Partner: Marcin Chmielewski

Institute of Electronic Materials Technology (PL)

Recent publications
1.Jarząbek D.M., Milczarek M., Wojciechowski T., Dziekoński C., Chmielewski M., The effect of metal coatings on the interfacial bonding strength of ceramics to copper in sintered Cu-SiC composites, CERAMICS INTERNATIONAL, ISSN: 0272-8842, DOI: 10.1016/j.ceramint.2017.01.056, pp.1-9, 2017
Abstract:

Cu-SiC composites are very promising materials which have high thermal and electrical conductivity and may find many applications. Unfortunately, the main disadvantage of these materials is the dissolution of silicon in copper at elevated temperature, which significantly reduces their properties. In order to overcome this problem particles can be coated with a protective material before sintering. In this paper– the influence of three different metallic coatings on bonding strength were investigated. SiC particles were coated with tungsten, chromium or titanium. As reference a material with uncoated particles was prepared. The experiments were carried out with the use of microtensile tester. The highest increase in strength was observed in the case of chromium coating. On the other hand, the titanium coating, which was of very poor quality, decrease the bonding strength in comparison with uncoated particles. Furthermore, scanning electron and optical microscopes were used to determine the mechanism of debonding.

Keywords:

Interfacial bonding strength, Metal matrix composites, Tensile strength, Silicon carbide particles

Affiliations:
Jarząbek D.M.-IPPT PAN
Milczarek M.-Warsaw University of Technology (PL)
Wojciechowski T.-Institute of Physics, Polish Academy of Sciences (PL)
Dziekoński C.-IPPT PAN
Chmielewski M.-Institute of Electronic Materials Technology (PL)
2.Piotrowski L., Chmielewski M., Kowalewski Z.L., The Dominant Influence of Plastic Deformation Induced Residual Stress on the Barkhausen Effect Signal in Martensitic Steels, JOURNAL OF NONDESTRUCTIVE EVALUATION, ISSN: 0195-9298, DOI: 10.1007/s10921-016-0389-x, Vol.36, No.10, pp.1-8, 2017
Abstract:

The paper presents the results of investigation of the influence of plastic deformation on the magnetic properties of martensitic steel (P91 grade). The properties of the hysteresis loops as well as of the Barkhausen effect (BE) signal are analysed for both tensile and compressive loading up to ε=10% of plastic deformation. The choice of the steel and of the deformation range is unique, since for such combination one can expect high residual stresses (both compressive and tensile) in the material that does not exhibit saturation of the BE intensity as a function of elastic stress. The obtained relationships show that for the low level of deformation the dislocation density changes may play a dominant role, yet for higher deformation level the residual stress becomes a dominant factor. It leads to the strong decrease of the BE signal for tensile deformation and an increase for the case of compression. It agrees well with the assumption that the tensile plastic deformation results in the compressive stresses appearance in the soft (magnetically active) sub-regions of the material whereas for the compression one can expect a residual stress of a tensile nature in those areas. Both deformation modes result in the increase of coercivity of the samples, yet the increase observed for the tensile deformation is significantly higher since both the residual compressive stress and increase of dislocation density have a strong effect on the material coercivity. The change of the hysteresis loops steepness agrees well with the notion of the dominant role of residual stresses too.

Keywords:

Barkhausen effect, Plastic deformation, Residual stress, Magnetic hysteresis, Coercivity

Affiliations:
Piotrowski L.-other affiliation
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Kowalewski Z.L.-IPPT PAN
3.Chmielewski M., Pietrzak K., Teodorczyk M., Nosewicz S., Jarząbek D., Zybała R., Bazarnik P., Lewandowska M., Strojny-Nędza A., Effect of metallic coating on the properties of copper-silicon carbide composites, APPLIED SURFACE SCIENCE, ISSN: 0169-4332, DOI: 10.1016/j.apsusc.2016.12.130, Vol.421, pp.159-169, 2017
Abstract:

In the presented paper a coating of SiC particles with a metallic layer were used to prepare copper matrix composite materials. The role of the layer was to protect the silicon carbide from decomposition and dissolution of silicon in the copper matrix during the sintering process. The SiC particles were covered by chromium, tungsten and titanium using Plasma Vapour Deposition method. After powder mixing of components, the final densification process via Spark Plasma Sintering (SPS) method at temperature 950C was provided. The almost fully dense materials were obtained (> 97.5%). The microstructure of obtained composites was studied using scanning electron microscopy as well as transmission electron microscopy. The microstructural analysis of composites confirmed that regardless of the type of deposited material, there is no evidence for decomposition process of silicon carbide in copper. In order to measure the strength of the interface between ceramic particles and the metal matrix, the micro tensile tests have been performed. Furthermore, thermal diffusivity was measured with the use of the laser pulse technique. In the context of performed studies, the tungsten coating seems to be the most promising solution for heat sink application. Compared to pure composites without metallic layer, Cu-SiC with W coating indicate the higher tensile strength and thermal diffusitivy, irrespective of an amount of SiC reinforcement. The improvement of the composite properties is related to advantageous condition of Cu-SiC interface characterized by well homogenity and low porosity, as well as individual properties of the tungsten coating material.

Keywords:

metal matrix composites, silicon carbide, metallic layers deposition, thermal conductovity, interface strength

Affiliations:
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Pietrzak K.-other affiliation
Teodorczyk M.-other affiliation
Nosewicz S.-IPPT PAN
Jarząbek D.-IPPT PAN
Zybała R.-Warsaw University of Technology (PL)
Bazarnik P.-Warsaw University of Technology (PL)
Lewandowska M.-other affiliation
Strojny-Nędza A.-Institute of Electronic Materials Technology (PL)
4.Nosewicz S., Rojek J., Chmielewski M., Pietrzak K., Discrete element modeling and experimental investigation of hot pressing of intermetallic NiAl powder, ADVANCED POWDER TECHNOLOGY, ISSN: 0921-8831, DOI: 10.1016/j.apt.2017.04.012, Vol.28, pp.1745-1759, 2017
Abstract:

This paper presents the numerical and experimental analysis of hot pressing of NiAl powder with an emphasis on the best possible representation of its main stages: initial powder compaction and pressure-assisted sintering. The numerical study has been performed within the discrete element framework. In the paper, an original viscoelastic model of hot pressing has been used. In order to ensure that the applied values of material parameters in numerical simulations are appropriate, the reference literature has been reviewed. It produced the relations and equations to estimate the values of all required sintering material parameters of the considered viscoelastic model. Numerical simulations have employed the geometrical model of the initial dense specimen generated by a special algorithm which uses the real grain distribution of powder. The numerical model has been calibrated and validated through simulations of the real process of hot pressing of intermetallic NiAl material. The kinetics of compaction, sintering and cooling stage indicated by the evolution of density, shrinkage and densification rate have been studied. The comparison of numerical and experimental results has shown a good performance of the developed numerical model.

Keywords:

Powder metallurgy; Hot pressing; Sintering; Simulation; Discrete element method; Nickel aluminide

Affiliations:
Nosewicz S.-IPPT PAN
Rojek J.-IPPT PAN
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Pietrzak K.-IPPT PAN
5.Nosewicz S., Rojek J., Chmielewski M., Pietrzak K., Lumelskyj D., Application of the Hertz formulation in the discrete element model of pressure-assisted sintering, GRANULAR MATTER, ISSN: 1434-5021, DOI: 10.1007/s10035-016-0699-9, Vol.19, No.1, pp.16-1-8, 2017
Abstract:

This paper presents the numerical modelling of initial powder compaction and pressure-assisted sintering performed by original viscoelastic discrete element model. The research is focused on the influence of the type of the model representing an elastic part of interparticle force. Two elastic contact models—linear and nonlinear Hertz model—have been implemented and used to analyse interaction of NiAl powder particles during compaction and sintering process. Numerical models have been validated using own experimental results. Microscopic effects (particle penetration) and macroscopic changes (relative density) have been compared. It has been shown that although both models represent properly macroscopic behaviour of the material at the sintering process, the Hertz model produces the results closer to the real experimental ones during the initial compaction stage. Evaluation of macroscopic quantities enables implementation of the discrete element model in the framework of the multiscale modelling framework which is currently developed for sintering processes.

Keywords:

Powder metallurgy, Sintering, Initial compaction, Elasticity, Discrete element method

Affiliations:
Nosewicz S.-IPPT PAN
Rojek J.-IPPT PAN
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Pietrzak K.-IPPT PAN
Lumelskyj D.-IPPT PAN
6.Chmielewski M., Pietrzak K., Strojny-Nędza A., Jarząbek D., Nosewicz S., Investigations of interface properties in copper-silicon carbide composites, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.1515/amm-2017-0200, Vol.62, No.2B, pp.1315-1318, 2017
Abstract:

This paper analyses the technological aspects of the interface formation in the copper-silicon carbide composite and its effect on the material’s microstructure and properties. Cu-SiC composites with two different volume content of ceramic reinforcement were fabricated by hot pressing (HP) and spark plasma sintering (SPS) technique. In order to protect SiC surface from its decomposition, the powder was coated with a thin tungsten layer using plasma vapour deposition (PVD) method. Microstructural analyses provided by scanning electron microscopy revealed the significant differences at metal-ceramic interface. Adhesion force and fracture strength of the interface between SiC particles and copper matrix were measured. Thermal conductivity of composites was determined using laser flash method. The obtained results are discussed with reference to changes in the area of metal-ceramic boundary.

Keywords:

copper matrix composites, silicon carbide, interface, thermal conductivity, adhesion

Affiliations:
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Pietrzak K.-IPPT PAN
Strojny-Nędza A.-Institute of Electronic Materials Technology (PL)
Jarząbek D.-IPPT PAN
Nosewicz S.-IPPT PAN
7.Strojny-Nędza A., Pietrzak K., Teodorczyk M., Basista M., Węglewski W., Chmielewski M., Influence of Material Ccating on the heat Transfer in a layered Cu-SiC-Cu Systems, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.1515/amm-2017-0199, Vol.62, No.2B, pp.1311-1314, 2017
Abstract:

This paper describes the process of obtaining Cu-SiC-Cu systems by way of spark plasma sintering. A monocrystalline form of silicon carbide (6H-SiC type) was applied in the experiment. Additionally, silicon carbide samples were covered with a layer of tungsten and molybdenum using chemical vapour deposition (CVD) technique. Microstructural examinations and thermal properties measurements were performed. A special attention was put to the metal-ceramic interface. During annealing at a high temperature, copper reacts with silicon carbide. To prevent the decomposition of silicon carbide two types of coating (tungsten and molybdenum) were applied. The effect of covering SiC with the aforementioned elements on the composite’s thermal conductivity was analyzed. Results were compared with the numerical modelling of heat transfer in Cu-SiC-Cu systems. Certain possible reasons behind differences in measurements and modelling results were discussed.

Keywords:

copper matrix composites, silicon carbide, interface, thermal conductivity, modelling

Affiliations:
Strojny-Nędza A.-Institute of Electronic Materials Technology (PL)
Pietrzak K.-IPPT PAN
Teodorczyk M.-other affiliation
Basista M.-IPPT PAN
Węglewski W.-IPPT PAN
Chmielewski M.-Institute of Electronic Materials Technology (PL)
8.Rojek J., Nosewicz S., Chmielewski M., MICRO-MACRO RELATIONSHIPS FROM DISCRETE ELEMENT SIMULATIONS OF SINTERING, INTERNATIONAL JOURNAL FOR MULTISCALE COMPUTATIONAL ENGINEERING, ISSN: 1543-1649, DOI: 10.1615/IntJMultCompEng.2017020322, Vol.15, No.4, pp.323-342, 2017
Abstract:

A two-scale modeling framework for sintering processes has been presented. Formulation of the micromechanical model of sintering developed in the discrete element method and basic relationships in the macroscopic model of sintering have been briefly reviewed. The methodology to determine macroscopic quantities–stress, strains, and constitutive viscous properties-from the discrete element simulations has been presented. This methodology has been applied to modeling of NiAl sintering. First, the discrete element model (DEM) has been calibrated by fitting the numerical densification curve to the experimental data. The DEM model with calibrated parameters has been used in simulations specially conceived to give macroscopic viscous moduli of the sintered material. Using the averaging procedures macroscopic stresses and strains have been calculated. Strain rates have been obtained differentiating the strain curves with respect to time. Finally, the viscous constitutive properties of the sintered material have been determined. The dependence of the shear and volumetric viscous moduli on the relative density (or equivalently) on the porosity has been obtained. It has been found that the numerical simulations predict a similar dependence as that assumed in the phenomenological macroscopic models. Thus, the validity of the micro-macro relationships obtained from the discrete element simulations of powder sintering has been confirmed. The proposed methodology allows us to use the discrete element model in the framework of multiscale modeling of sintering.

Keywords:

discrete element method, sintering, simulation, micro-macro relationships, multiscale modeling

Affiliations:
Rojek J.-IPPT PAN
Nosewicz S.-IPPT PAN
Chmielewski M.-Institute of Electronic Materials Technology (PL)
9.Chmielewski M., Pietrzak K., Strojny-Nędza A., Kaszyca K., Zybala R., Bazarnik P., Lewandowska M., Nosewicz S., Microstructure and thermal properties of Cu-SiC composite materials depending on the sintering technique, SCIENCE OF SINTERING, ISSN: 0350-820X, DOI: 10.2298/SOS1701011C, Vol.49, pp.11-22, 2017
Abstract:

The presented paper investigates the relationship between the microstructure and thermal properties of copper–silicon carbide composites obtained through hot pressing (HP) and spark plasma sintering (SPS) techniques. The microstructural analysis showed a better densification in the case of composites sintered in the SPS process. TEM investigations revealed the presence of silicon in the area of metallic matrix in the region close to metal ceramic boundary. It is the product of silicon dissolving process in copper occurring at an elevated temperature. The Cu-SiC interface is significantly defected in composites obtained through the hot pressing method, which has a major influence on the thermal conductivity of materials.

Keywords:

Metal matrix composites; Silicon carbide; Interface; Spark plasma sintering; Thermal conductivity.

Affiliations:
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Pietrzak K.-IPPT PAN
Strojny-Nędza A.-Institute of Electronic Materials Technology (PL)
Kaszyca K.-other affiliation
Zybala R.-Warsaw University of Technology (PL)
Bazarnik P.-Warsaw University of Technology (PL)
Lewandowska M.-other affiliation
Nosewicz S.-IPPT PAN
10.Chmielewski M., Nosewicz S., Kurpaska Ł., Romelczyk B., Evolution of material properties during the sintering process of Cr-Re-Al2O3 composites, COMPOSITES PART B-ENGINEERING, ISSN: 1359-8368, DOI: 10.1016/j.compositesb.2016.04.065, Vol.98, pp.88-96, 2016
Abstract:

This paper constitutes an analysis of the effect of heat treatment time on the properties of Cr-Re-Al2O3 composite materials. It was found that as a result of sintering, rhenium is dissolved in chromium to create chromium-rhenium solid solution. This process is time-dependent, therefore as the time extends, the structure of material becomes homogenous, which improves its mechanical properties. Within the frame of herein presented studies, a series of technological tests have been carried out for a constant sintering temperature (1450°C) and pressure (30 MPa), with the use of a variable holding time in the maximum temperature. As a result, changes in the structure of Crsingle bondRe matrix have been determined and the resulting changes in the properties of composite. Based on those tests, optimal conditions of the sintering process have been determined from the point of view of obtaining a homogenous structure and the most beneficial properties of Cr-Re-Al2O3 composites.

Keywords:

Metal-matrix composites (MMCs), Mechanical properties, Mechanical testing, Sintering

Affiliations:
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Nosewicz S.-IPPT PAN
Kurpaska Ł.-National Centre for Nuclear Research (PL)
Romelczyk B.-Warsaw University of Technology (PL)
11.Wejrzanowski T., Grybczuk M., Chmielewski M., Pietrzak K., Kurzydłowski K.J., Strojny-Nędza A., Thermal conductivity of metal-graphene composites, MATERIALS AND DESIGN, ISSN: 0261-3069, DOI: 10.1016/j.matdes.2016.03.069, Vol.99, pp.163-173, 2016
Abstract:

In this paper the results of numerical simulations and experimental studies are presented which describe potential and limitation of applications of single-layer (SLG) and multi-layer (MLG) graphene for thermal conductivity enhancement (TCE) of copper. A series of composite structures were studied which are representative of most widely used systems. The influence of structural parameters on the macroscopic thermal conductivity was analyzed, both experimentally and by numerical simulations. Analytical and Finite Element Method modeling were carried out to investigate a wide range of phenomena, including the effect of copper-MLG interface, copper grain size, volume fraction, thickness and orientation of MLG platelets as well as spatial distribution of MLG defined by percolation factor. Both modeling and the experimental results show that the volume fraction of MLG regions, their size, orientation and spatial distribution may significantly affect the thermal conductivity of metal matrix composites. TCE can be obtained for the laminate-like structure or particulate composites with highly aligned MLG regions. The thermal conductivity of such composites is strongly anisotropic and enhanced in the direction perpendicular to the layers. The results obtained in this study predict that SLG will have a negative effect on the thermal conductivity of copper matrix composites.

Keywords:

Thermal conductivity, Composites, Graphene, Finite element method

Affiliations:
Wejrzanowski T.-other affiliation
Grybczuk M.-other affiliation
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Pietrzak K.-other affiliation
Kurzydłowski K.J.-Warsaw University of Technology (PL)
Strojny-Nędza A.-Institute of Electronic Materials Technology (PL)
12.Chmielewski M., Nosewicz S., Jakubowska D., Lewandowska M., Mizera J., Rojek J., Bazarnik P., The influence of sintering time on the microstructural properties of chromium-rhenium matrix composites, International Journal of Refractory Metals and Hard Materials, ISSN: 0263-4368, DOI: 10.1016/j.ijrmhm.2016.05.017, Vol.59, pp.78-86, 2016
Abstract:

This paper comprises the results of studies of the changes in the structure of Cr-Re-Al2O3 metal matrix depending on heat treatment time in sintering temperature. The density of material with the following composition: 95%(75%Cr-25%Al2O3)+5%Re was increased using the technique of sintering under pressure (30MPa) at the temperature of 1450°C. As a result, materials characterized by a high relative density (< 97% of theoretical density) were obtained. Next, they were subjected to structural tests including scanning and transmission electron microscopy as well as X-ray diffraction. Changes in the phase composition, grains size and parameters of crystallographic structure depending on heat treatment time were analysed. It was found that during sintering rhenium is dissolved in the chromium matrix and Cr-Re solid solution is formed. When sintering time is extended to 120 min, the matrix of the composite becomes completely homogenous, which results in an increased strength of the composite.

Keywords:

Metal matrix composites, Rhenium, Hot pressing, Microstructure analysis, XRD

Affiliations:
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Nosewicz S.-IPPT PAN
Jakubowska D.-other affiliation
Lewandowska M.-other affiliation
Mizera J.-other affiliation
Rojek J.-IPPT PAN
Bazarnik P.-Warsaw University of Technology (PL)
13.Chmielewski M., Pietrzak K., Basista M., Węglewski W., Rhenium doped chromium–alumina composites for high-temperature applications, International Journal of Refractory Metals and Hard Materials, ISSN: 0263-4368, DOI: 10.1016/j.ijrmhm.2015.07.012, Vol.54, pp.196-202, 2016
Abstract:

Dense chromium–alumina composites doped with rhenium have been developed by the hot pressing method (bulk composite) and plasma spraying (composite coating). The obtained materials show superior mechanical properties, insensitivity to chemically aggressive environment, good resistance to frictional wear and oxidation at elevated temperature. These enhanced properties make the Cr/Re/Al2O3 composites interesting structural materials for energy and transport applications operating in demanding service conditions, e.g. fluidal boilers in power plants or valve seats in combustion engines.

Keywords:

Metal–ceramic composites, Powder technology, Mechanical properties, Coatings

Affiliations:
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Pietrzak K.-other affiliation
Basista M.-IPPT PAN
Węglewski W.-IPPT PAN
14.Pietrzak K., Sobczak N., Chmielewski M., Homa M., Gazda A., Zybała R., Strojny-Nędza A., Effects of Carbon Allotropic Forms on Microstructure and Thermal Properties of Cu-C Composites Produced by SPS, Journal of Materials Engineering and Performance, ISSN: 1059-9495, DOI: 10.1007/s11665-015-1851-0, Vol.25, No.8, pp.3077-3083, 2016
Abstract:

Combination of extreme service conditions and complex thermomechanical loadings, e.g., in electronics or power industry, requires using advanced materials with unique properties. Dissipation of heat generated during the operation of high-power electronic elements is crucial from the point of view of their efficiency. Good cooling conditions can be guaranteed, for instance, with materials of very high thermal conductivity and low thermal expansion coefficient, and by designing the heat dissipation system in an accurate manner. Conventional materials such as silver, copper, or their alloys, often fail to meet such severe requirements. This paper discusses the results of investigations connected with Cu-C (multiwall carbon nanotubes (MWNTs), graphene nanopowder (GNP), or thermally reduced graphene oxide (RGO)) composites, produced using the spark plasma sintering technique. The obtained composites are characterized by uniform distribution of a carbon phase and high relative density. Compared with pure copper, developed materials are characterized by similar thermal conductivity and much lower values of thermal expansion coefficient. The most promising materials to use as heat dissipation elements seems to be copper-based composites reinforced by carbon nanotubes (CNTs) and GNP.

Keywords:

copper matrix composites, graphene, spark plasma sintering, thermal properties

Affiliations:
Pietrzak K.-other affiliation
Sobczak N.-other affiliation
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Homa M.-Foundry Research Institute (PL)
Gazda A.-Foundry Research Institute (PL)
Zybała R.-Warsaw University of Technology (PL)
Strojny-Nędza A.-Institute of Electronic Materials Technology (PL)
15.Jarząbek D.M., Chmielewski M., Dulnik J., Strojny-Nędza A., The Influence of the Particle Size on the Adhesion Between Ceramic Particles and Metal Matrix in MMC Composites, Journal of Materials Engineering and Performance, ISSN: 1059-9495, DOI: 10.1007/s11665-016-2107-3, Vol.25, No.8, pp.3139-3145, 2016
Abstract:

This study investigated the influence of the particle size on the adhesion force between ceramic particles and metal matrix in ceramic-reinforced metal matrix composites. The Cu-Al2O3 composites with 5 vol.% of ceramic phase were prepared by a powder metallurgy process. Alumina oxide powder as an electrocorundum (Al2O3) powder with different particle sizes, i.e., fine powder <3 µm and coarse powder of 180 µm was used as a reinforcement. Microstructural investigations included analyses using scanning electron microscopy with an integrated EDS microanalysis system and transmission microscopy. In order to measure the adhesion force (interface strength), we prepared the microwires made of the investigated materials and carried out the experiments with the use of the self-made tensile tester. We have observed that the interface strength is higher for the sample with coarse particles and is equal to 74 ± 4 MPa and it is equal to 68 ± 3 MPa for the sample with fine ceramic particles.

Keywords:

adhesion, interface strength, metal matrix composites, nanocomposites, tensile test

Affiliations:
Jarząbek D.M.-IPPT PAN
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Dulnik J.-IPPT PAN
Strojny-Nędza A.-Institute of Electronic Materials Technology (PL)
16.Chmielewski M., Pietrzak K., Metal-ceramic functionally graded materials – manufacturing, characterization, application, BULLETIN OF THE POLISH ACADEMY OF SCIENCES: TECHNICAL SCIENCES, ISSN: 0239-7528, DOI: 10.1515/bpasts-2016-0017, Vol.64, No.1, pp.151-160, 2016
Abstract:

Functionally graded materials (FGMs) belong to a new, continuously developing group of materials, finding application in various branches of industry. The idea of freely designing their construction profile, restricted only by the available manufacturing techniques, enables obtaining materials with composition and structure gradients having unprecedented properties. In this paper, selected results of works carried out by the authors and relating to the application of the developed metal-ceramic composites were presented in order to manufacture functionally graded materials for target purposes. Gradient structures with various construction profiles that can play different roles were produced on the basis on the following material pairs: Cr-Al2O3, NiAl-Al2O3 and Cu-AlN. Manufacturing conditions, microstructure characteristics and selected properties, crucial from the point of view of future applications, were presented.

Keywords:

metal-ceramic functionally graded materials, manufacturing, characterization, application

Affiliations:
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Pietrzak K.-other affiliation
17.Jurczak K., Rojek J., Nosewicz S., Lumelskyy D., Bochenek K., Chmielewski M., Pietrzak K., Modelowanie wstępnego prasowania proszków metodą elementów dyskretnych, HUTNIK - WIADOMOŚCI HUTNICZE, ISSN: 1230-3534, DOI: 10.15199/24.2016.1.1, Vol.83, No.1, pp.3-7, 2016
Abstract:

W niniejszym artykule zaprezentowano wyniki modelowania zagęszczania proszku stanowiącego wstępny etap procesu prasowania na gorąco. Modelowanie numeryczne zrealizowano metodą elementów dyskretnych z wykorzystaniem kulistych cząstek. Analizę skoncentrowano na badaniu mechanizmów zagęszczania proszku przy ciśnieniu do 50 MPa oraz poszukiwaniu modeli odpowiednich przy zastosowanych warunkach realizacji procesu. Symulacje numeryczne wykonano wykorzystując dwa modele oddziaływania cząstek proszku: sprężysty model Hertza-Mindlina-Deresiewicza oraz plastyczny model Storåkersa. Wyniki numeryczne zostały porównane z wynikami laboratoryjnymi prasowania proszku NiAl. Otrzymano dużą zgodność wyników eksperymentalnych i numerycznych.

This paper presents the results of discrete element simulation of powder compaction which is the initial stage in the hot pressing process. Numerical simulation has been performed by discrete element method with using spherical particles. The research has been focused on densification mechanisms under pressure 50 MPa and models appropriate for these conditions. Numerical simulations have been carried out for two contact models: elastic Hertz-Mindlin-Deresiewicz and plastic - Storåkers. Numerical results and results from laboratory test of the uniaxial pressing of NiAl powder have been compared. The obtained results of numerical simulation and laboratory tests showing a good agreement.

Keywords:

metoda elementów dyskretnych, prasowanie proszków, materiały intermetaliczne, discrete element method, powder compaction, intermetallics

Affiliations:
Jurczak K.-IPPT PAN
Rojek J.-IPPT PAN
Nosewicz S.-IPPT PAN
Lumelskyy D.-IPPT PAN
Bochenek K.-IPPT PAN
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Pietrzak K.-other affiliation
18.Rojek J., Nosewicz S., Jurczak K., Chmielewski M., Bochenek K., Pietrzak K., Discrete element simulation of powder compaction in cold uniaxial pressing with low pressure, Computational Particle Mechanics, ISSN: 2196-4378, DOI: 10.1007/s40571-015-0093-0, Vol.3, pp.513-524, 2016
Abstract:

This paper presents numerical studies of powder compaction in cold uniaxial pressing. The powder compaction in this work is considered as an initial stage of a hot pressing process so it is realized with relatively low pressure (up to 50 MPa). Hence the attention has been focused on the densification mechanisms at this range of pressure and models suitable for these conditions. The discrete element method employing spherical particles has been used in the numerical studies. Numerical simulations have been performed for two different contact models—the elastic Hertz–Mindlin–Deresiewicz model and the plastic Storåkers model. Numerical results have been compared with the results of laboratory tests of the die compaction of the NiAl powder. Comparisons have shown that the discrete element method is capable to represent properly the densification mechanisms by the particle rearrangement and particle deformation.

Keywords:

Discrete element method, Simulation, Powder compaction, Cold uniaxial pressing

Affiliations:
Rojek J.-IPPT PAN
Nosewicz S.-IPPT PAN
Jurczak K.-IPPT PAN
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Bochenek K.-IPPT PAN
Pietrzak K.-other affiliation
19.Jarząbek D.M., Chmielewski M., Wojciechowski T., The measurement of the adhesion force between ceramic particles and metal matrix in ceramic reinforced-metal matrix composites, COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING, ISSN: 1359-835X, DOI: 10.1016/j.compositesa.2015.05.025, Vol.76, pp.124-130, 2015
Abstract:

This paper presents the method for measurement of the adhesion force and fracture strength of the interface between ceramic particles and metal matrix in ceramic reinforced-metal matrix composites. Three samples with the following Cu to Al2O3 ratio (in vol.%) were prepared: 98.0Cu/2.0Al2O3, 95.0Cu/5.0Al2O3 and 90Cu/10Al2O3. Furthermore, microwires which contain a few ceramic particles were produced by means of electro etching. The microwires with clearly exposed interface were tested with use of the microtensile tester. The microwires usually break exactly at the interface between the metal matrix and ceramic particle. The force and the interface area were carefully measured and then the fracture strength of the interface was determined. The strength of the interface between ceramic particle and metal matrix was equal to 59 ± 8 MPa and 59 ± 11 MPa in the case of 2% and 5% Al2O3 to Cu ratio, respectively. On the other hand, it was significantly lower (38 ± 5 MPa) for the wires made of composite with 10% Al2O3.

Keywords:

Nanocomposites, Metal matrix composites, Adhesion, Interface

Affiliations:
Jarząbek D.M.-IPPT PAN
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Wojciechowski T.-Institute of Physics, Polish Academy of Sciences (PL)
20.Chmielewski M., Nosewicz S., Rojek J., Pietrzak K., Mackiewicz S., Romelczyk B., A study of densification and microstructure evolution during hot pressing of NiAl/Al2O3 composite, Advanced Composite Materials, ISSN: 0924-3046, DOI: 10.1080/09243046.2013.879408, Vol.24, No.1, pp.57-66, 2015
Abstract:

Evolution of the density and the microstructure during hot pressing of NiAl/Al2O3 composite has been investigated in the present paper. In particular, the effect of the process parameters, viz. compacting pressure, sintering temperature and sintering time, on the evolution of the density of the intermetallic–ceramic composite has been studied. Evolution of the density has been related to microstructure changing. Porosity, pore structures and grains rearrangement have been analysed in microscopic observations.

Keywords:

hot pressing, sintering, intermetallic–ceramic composite, density evolution, microstructure

Affiliations:
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Nosewicz S.-IPPT PAN
Rojek J.-IPPT PAN
Pietrzak K.-other affiliation
Mackiewicz S.-IPPT PAN
Romelczyk B.-Warsaw University of Technology (PL)
21.Rojek J., Nosewicz S., Pietrzak K., Chmielewski M., Evaluation of macroscopic stresses in discrete element models of sintering processes, COMPUTER METHODS IN MATERIALS SCIENCE / INFORMATYKA W TECHNOLOGII MATERIAŁÓW, ISSN: 1641-8581, Vol.15, No.1, pp.219-255, 2015
Abstract:

This paper presents investigation of macroscopic stresses in powder metallurgy process modelled with the discrete element method. The discrete element model belongs to the class of micromechanical models. In the DEM model the material is represented by an assembly of particles interacting by contact forces and the method is formulated in terms of forces and displacements. In order to evaluate macroscopic stresses a special upscaling procedure is necessary. The paper presents basic formulation of the discrete element method with special attention for the contact interaction models for powder compaction and sintering. A method to evaluate macroscopic stresses based on the two level averaging is presented. The discrete element model of sintering is verified using own experimental results. Macroscopic stresses are calculated for the whole process including loading, heating, sintering, cooling and unloading. It has been found out that the macroscopic stresses are consistent with changing process parameters. The procedure is suitable for multiscale modelling of sintering.

Keywords:

sintering, modeling, discrete element method, macroscopic stresses

Affiliations:
Rojek J.-IPPT PAN
Nosewicz S.-IPPT PAN
Pietrzak K.-other affiliation
Chmielewski M.-Institute of Electronic Materials Technology (PL)
22.Węglewski W., Basista M., Manescu A., Chmielewski M., Pietrzak K., Schubert Th., Effect of grain size on thermal residual stresses and damage in sintered chromium–alumina composites: Measurement and modeling, COMPOSITES PART B-ENGINEERING, ISSN: 1359-8368, DOI: 10.1016/j.compositesb.2014.06.027, Vol.67, pp.119-124, 2014
Abstract:

In this paper we present the results of experimental measurements and numerical modeling of the effect of particle size on the residual thermal stresses arising in sintered metal–matrix composites after cooling down from the fabrication temperature. On example of novel Cr(Re)/Al2O3 composites processed by (i) spark plasma sintering and (ii) hot pressing the residual thermal stresses are measured by neutron diffraction technique and determined by a FEM model based on micro-CT scans of the material microstructure. Then numerical model of microcracking induced by residual stresses is applied to predict the effective Young modulus of the damaged composite. Comparison of the numerical results with the measured data of the residual stresses and Young’s modulus is presented and fairly good agreement is noted.

Keywords:

Metal–matrix composites (MMC), Residual/internal stress, Finite element analysis (FEA), Sintering

Affiliations:
Węglewski W.-IPPT PAN
Basista M.-IPPT PAN
Manescu A.-Universita degli Studi di Ancona (IT)
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Pietrzak K.-other affiliation
Schubert Th.-Fraunhofer Institut für Fertigungstechnik und Angewandte Materialforschung (DE)
23.Nosewicz S., Rojek J., Mackiewicz S., Chmielewski M., Pietrzak K., Romelczyk B., The influence of hot pressing conditions on mechanical properties of nickel aluminide/alumina composite, Journal of Composite Materials, ISSN: 0021-9983, DOI: 10.1177/0021998313511652, Vol.48, No.29, pp.3577-3589, 2014
Abstract:

The influence of hot pressing conditions on mechanical properties of nickel aluminide/alumina composite has been investigated in the present paper. In particular, effect of the process parameters, viz. compacting pressure, sintering temperature and sintering time on the evolution of density, elastic constants and tensile strength properties of the intermetallic-ceramic composite has been studied. Elastic constants, the Young's modulus and Poisson's ratio, have been evaluated using an ultrasonic testing method, and the tensile strength has been determined by a Brazilian-type splitting test. Microscopic observations of microstructure evolution complemented the experimental procedure. Experimental results have been confronted with theoretical models showing a good agreement between the data compared.

Keywords:

Hot pressing, sintering, intermetallic-ceramic composite, elastic properties, Brazilian test, tensile strength, ultrasonic method

Affiliations:
Nosewicz S.-IPPT PAN
Rojek J.-IPPT PAN
Mackiewicz S.-IPPT PAN
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Pietrzak K.-other affiliation
Romelczyk B.-Warsaw University of Technology (PL)
24.Chmielewski M., Pietrzak K., Strojny-Nędza A., Dubiel B., Czyrska-Filemonowicz A., Effect of rhenium addition on the strengthening of chromium-alumina composite materials, INTERNATIONAL JOURNAL OF MATERIALS RESEARCH, ISSN: 1862-5282, DOI: 10.3139/146.111002, Vol.105, No.2, pp.200-207, 2014
Abstract:

Chromium–alumina composites are well known for their good mechanical properties in comparison to pure ceramics or metals. These composites are characterized by high hardness and high mechanical strength. The aim of the present work was to improve the properties of chromium–alumina composites even more and expand the range of their possible applications by addition of rhenium. To achieve this goal, chromium–alumina composites containing 2 and 5 vol.% of rhenium were produced via powder metallurgy. The microstructural characterization of the processed material was performed using light microscopy, scanning and transmission electron microscopy as well as X-ray diffraction analysis. Measurement of selected properties such as Young's modulus, bend strength and hardness revealed an advantageous influence of rhenium additions. The results are discussed in terms of the influence of rhenium volume content on the microstructure and on the physical and mechanical properties of the chromium–alumina composites. The solid solution is only partially formed. The properties strongly depend on the amount and distribution of both aluminium oxide and rhenium content.

Affiliations:
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Pietrzak K.-other affiliation
Strojny-Nędza A.-Institute of Electronic Materials Technology (PL)
Dubiel B.-AGH University of Science and Technology (PL)
Czyrska-Filemonowicz A.-AGH University of Science and Technology (PL)
25.Chmielewski M., Nosewicz S., Pietrzak K., Rojek J., Strojny-Nędza A., Mackiewicz S., Dutkiewicz J., Sintering Behavior and Mechanical Properties of NiAl, Al2O3, and NiAl-Al2O3 Composites, Journal of Materials Engineering and Performance, ISSN: 1059-9495, DOI: 10.1007/s11665-014-1189-z, Vol.23, No.11, pp.3875-3886, 2014
Abstract:

It is commonly known that the properties of sintered materials are strongly related to technological conditions of the densification process. This paper shows the sintering behavior of a NiAl-Al2O3 composite, and its individual components sintered separately. Each kind of material was processed via the powder metallurgy route (hot pressing). The progress of sintering at different stages of the process was tested. Changes in the microstructure were examined using scanning and transmission electron microscopy. Metal-ceramics interface was clean and no additional phases were detected. Correlation between the microstructure, density, and mechanical properties of the sintered materials was analyzed. The values of elastic constants of NiAl/Al2O3 were close to intermetallic ones due to the volume content of the NiAl phase particularly at low densities, where small alumina particles had no impact on the composite’s stiffness. The influence of the external pressure of 30 MPa seemed crucial for obtaining satisfactory stiffness for three kinds of the studied materials which were characterized by a high dense microstructure with a low number of isolated spherical pores.

Keywords:

ceramics, composites, electron, intermetallic, metallic matrix, microscopy, powder metallurgy, sintering, structural

Affiliations:
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Nosewicz S.-IPPT PAN
Pietrzak K.-other affiliation
Rojek J.-IPPT PAN
Strojny-Nędza A.-Institute of Electronic Materials Technology (PL)
Mackiewicz S.-IPPT PAN
Dutkiewicz J.-Institute of Metallurgy and Materials Science, Polish Academy of Sciences (PL)
26.Augustyniak B., Chmielewski M., Piotrowski L., Kiełczyński W., Prokop K., Kukla D., Pomiar naprężeń własnych metodą Barkhausena za pomocą sondy z wirującym polem magnetycznym, ENERGETYKA, PROBLEMY ENERGETYKI I GOSPODARKI PALIWOWO-ENERGETYCZNEJ, ISSN: 0013-7294, Vol.11, pp.641-643, 2014
Abstract:

Efekt Barkhausena (EB) kojarzony jest z impulsami napięcia indukowanymi w cewce detekcyjnej zbliżonej do magnesowanej płyty. Typowa sonda efektu Barkhausena składa się z elektromagnesu jarzmowego (typu C) i cewki detekcyjnej z rdzeniem ferrytowym [1]. Natężenie efektu Barkhausena zależy od mikrostruktury (wielkości ziarna, morfologii wydzieleń i dyslokacji) oraz od poziomu naprężeń [2]. Magnesowanie jest łatwiejsze, gdy kierunek pola magnetycznego sondy zgodny jest z kierunkiem działania naprężeń rozciągających i trudniejsze, gdy magnesowany jest materiał poddany działaniu naprężeń ściskających. Pomiar naprężeń z wykorzystaniem efektu Barkhausena ma wiele zalet: krótki czas pomiaru (kilkanaście sekund), względnie proste przygotowanie powierzchni (usunięcie warstwy tlenków szlifierką oscylacyjną z papierem ściernym o gradacji powyżej 100). W celu określenia składowych płaskiego stanu naprężenia konieczne jest wyznaczenie rozkładu kątowego natężenia EB [2, 3]. W artykule opisano wyniki badań stanu naprężenia za pomocą nowo opracowanego aparatu wyposażonego w sondę, która generuje w badanym elemencie namagnesowanie o skokowo zmiennym kierunku magnesowania. Aparat ten umożliwia automatyczny pomiar rozkładów kątowych natężenia EB. Badania te są realizowane w ramach projektu NCBiR nr PBS1/A9/14/2012 pt. Opracowanie magnetycznej metody oceny stanu naprężeń w materiałach konstrukcyjnych zwłaszcza anizotropowych. Zdaniem Autorów jest to rozwiązanie o lepszych walorach użytkowych niż proponowane w poprzednich opracowaniach [4, 5]. Anizotropowość właściwości magnetycznych (wynikająca np. z tekstury struktury ziaren) ujawnia się w eliptycznym, a nie kołowym rozkładzie kątowym natężenia EB. Oczywista jest konieczność uwzględnienia tej anizotropii przy badaniu stanu naprężenia tą technika. Poniżej podano przykłady badania stanu naprężenia nowym układem dla złącz spawanych wykonanych z praktycznie izotropowej magnetycznie stali oraz dla stali z wyraźną anizotropią magnetyczną.

Affiliations:
Augustyniak B.-Gdansk University of Technology (PL)
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Piotrowski L.-other affiliation
Kiełczyński W.-other affiliation
Prokop K.-other affiliation
Kukla D.-other affiliation
27.Nosewicz S., Rojek J., Pietrzak K., Chmielewski M., Viscoelastic discrete element model of powder sintering, POWDER TECHNOLOGY, ISSN: 0032-5910, DOI: 10.1016/j.powtec.2013.05.020, Vol.246, pp.157-168, 2013
Abstract:

This paper presents an original viscoelastic model of powder sintering developed within the discrete element framework. The viscous model used by other authors has been enriched by adding a spring connected in series to the viscous rheological element. In this way elastic and viscous effects in the particle interaction during sintering are treated using the Maxwell viscoelasticity. The new numerical model has been verified through simulation of simple problems of free sintering and sintering under pressure. Sintering processes have been treated as isothermic. In order to accelerate the analysis an algorithmic mass scaling has been used allowing to use larger time steps in the explicit time integration scheme. The results obtained using the new model are consistent with the standard viscous model. At the same time, a much better efficiency of the new model in comparison to the standard viscous one has been found because the critical time steps required by the viscoelastic model are much larger than those required by the viscous model. The new model has been applied to the simulation of real process of sintering of NiAl powder. The kinetics of sintering indicated by the evolution of density has been studied. The comparison of numerical and experimental results has shown a good performance of the developed numerical model.

Keywords:

Powder sintering, Simulation, Discrete element method, Viscoelastic model

Affiliations:
Nosewicz S.-IPPT PAN
Rojek J.-IPPT PAN
Pietrzak K.-other affiliation
Chmielewski M.-Institute of Electronic Materials Technology (PL)
28.Chmielewski M., Węglewski W., Comparison of experimental and modelling results of thermal properties in Cu-AlN composite materials, BULLETIN OF THE POLISH ACADEMY OF SCIENCES: TECHNICAL SCIENCES, ISSN: 0239-7528, DOI: 10.2478/bpasts-2013-0050, Vol.61, No.2, pp.507-514, 2013
Abstract:

Copper-based composites could be widely used in automotive, electronic or electrical industry due to their very promising thermal properties. In the present paper, Cu-AlN metal matrix composites with ceramic volume fractions between 0.1 and 0.4 were fabricated by hot pressing method in vacuum. Dependence of the coefficient of thermal expansion (CTE) and the thermal conductivity (TC) on the chemical composition of composites has been investigated. The measured values of the thermal expansion coefficient have been compared with the analytical models’ predictions. A numerical model based on FEAP 7.5 in 3D space has been used to evaluate the influence of the porosity on the thermal properties (thermal conductivity) of the composite. A fairly good correlation between the FEM results and the experimental measurements has been obtained.

Keywords:

thermal properties, porosity, copper-based composites

Affiliations:
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Węglewski W.-IPPT PAN
29.Basista M., Pietrzak K., Węglewski W., Chmielewski M., Kompozyty spiekane Cr-Al2O3 z dodatkiem renu. Wytwarzanie, właściwości, modelowanie, zastosowania, RUDY I METALE NIEŻELAZNE, ISSN: 0035-9696, Vol.R58, No.10, pp.556-563, 2013
Abstract:

Celem pracy było zbadanie wpływu dodatku renu na właściwości termomechaniczne i użytkowe kompozytów Cr-Al2O3 wytwarzanych metodą spiekania pod ciśnieniem w prasie HP oraz metodą Spark Plasma Sintering (SPS). Uzyskano kompozyty o gęstości przekraczającej 98% gęstości teoretycznej. Właściwości mechaniczne (m.in. moduł Younga, wytrzymałość na zginanie, twardość, odporność na pękanie, granica plastycznośći) oraz odporność na utlenianie wytworzonych materiałów są obiecujące. Zbudowano model numeryczny do obliczeń wielkości naprężeń resztkowych obecnych w materiałach faz kompozytu po procesie spiekania oraz modułów sprężystości. Wykorzystano w tym celu obrazy rzeczywistej mikrostruktury kompozytu otrzymane z tomografii komputerowej. Uzyskano dobrą zgodność wyników modelu z wynikami pomiarów naprężeń metodą XRD. Przedstawiono ponadto porównanie wyników obliczeń numerycznych i pomiarów modułu Younga przy zastosowaniu różnych metod

Keywords:

kompozyty MMC, metalurgia proszków, modelowanie MES, mikrotomografia komputerowa, naprężenia resztkowe

Affiliations:
Basista M.-IPPT PAN
Pietrzak K.-other affiliation
Węglewski W.-IPPT PAN
Chmielewski M.-Institute of Electronic Materials Technology (PL)
30.Rojek J., Nosewicz S., Pietrzak K., Chmielewski M., Simulation of Powder Sintering Using a Discrete Element Model, ACTA MECHANICA ET AUTOMATICA, ISSN: 1898-4088, DOI: 10.2478/ama-2013-0030, Vol.7, pp.175-179, 2013
Abstract:

This paper presents numerical simulation of powder sintering. The numerical model introduced in this work employs the discrete element method which assumes that material can be modelled by a large assembly of discrete elements (particles) of spherical shape interacting among one another. Modelling of sintering requires introduction of the cohesive interaction among particles representing interparticle sintering forces. Numerical studies of sintering have been combined with experimental studies which provided data for calibration and validation of the model. In the laboratory tests evolution of microstructure and density during sintering have been studied. Comparison of numerical and experimental results shows a good performance of the numerical model developed

Keywords:

Powder Sintering, Simulation, Discrete Element Method

Affiliations:
Rojek J.-IPPT PAN
Nosewicz S.-IPPT PAN
Pietrzak K.-other affiliation
Chmielewski M.-Institute of Electronic Materials Technology (PL)
31.Węglewski W., Basista M., Chmielewski M., Pietrzak K., Modeling of thermally induced damage in the processing of Cr–Al2O3 composites, COMPOSITES PART B-ENGINEERING, ISSN: 1359-8368, DOI: 10.1016/j.compositesb.2011.07.016, Vol.43B, No.2, pp.255-264, 2012
Abstract:

Thermal stresses induced during the cooling of Cr–Al2O3 (MMC) processed by sintering are modeled numerically using the FEA. The composite microstructure is modeled as (i) random distribution of ceramic particles (voxels) in the metal matrix, and (ii) using micro-CT scans of the real microstructure transformed into a FE mesh. Numerical simulations of the thermal residual stresses are compared with the test data measured by X-ray diffraction. A simple numerical model is then proposed to predict the overall elastic properties of the composite with account of the porosity and damage induced by the thermal stresses. Comparison of the model predictions with the measured data for Young’s modulus is presented.

Keywords:

Metal-matrix composites (MMCs), Residual/internal stress, Finite element analysis (FEA), Sintering

Affiliations:
Węglewski W.-IPPT PAN
Basista M.-IPPT PAN
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Pietrzak K.-IPPT PAN
32.Augustyniak B., Piotrowski L., Chmielewski M., Kowalewski Z.L., Comparative study with magnetic techniques of P91 and 13HMF steels properties subjected to fatigue tests, Journal of Electrical Engineering-Elektrotechnicky Casopis, ISSN: 1335-3632, Vol.63, No.7, pp.15-18, 2012
33.Nosewicz Sz., Rojek J., Pietrzak K., Chmielewski M., Kaliński D., Modelowanie procesu spiekania materiałów dwufazowych metodą elementów dyskretnych, RUDY I METALE NIEŻELAZNE, ISSN: 0035-9696, Vol.57, No.9, pp.599-603, 2012
Abstract:

W niniejszym artykule zostały przedstawione nowe wyniki modelowania procesu spiekania metodą elementów dyskretnych. W sformułowaniu teoretycznym dla części sprężystej zastosowano model kontaktu Hertza w celu lepszego odwzorowania oddziaływania elementów kulistych w trakcie prasowania. Sformułowanie i implementację modelu rozszerzono na przypadek spiekania materiałów dwufazowych. Na podstawie badań literaturowych wyznaczono parametry materiałowe procesu, które zostały następnie zweryfikowane za pomocą wyników eksperymentalnych. Wyniki numeryczne ewolucji gęstości próbki porównano z wynikami doświadczalnymi otrzymując dużą zgodność.

Keywords:

materiały dwufazowe, metalurgia proszków, spiekanie, metoda elementów dyskretnych

Affiliations:
Nosewicz Sz.-IPPT PAN
Rojek J.-IPPT PAN
Pietrzak K.-IPPT PAN
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Kaliński D.-other affiliation
34.Augustyniak B., Piotrowski L., Chmielewski M., Kowalewski Z.L., Właściwości magneto-akustyczne degradowanych próbek stali 13HMF oraz P91, ENERGETYKA, PROBLEMY ENERGETYKI I GOSPODARKI PALIWOWO-ENERGETYCZNEJ, ISSN: 0013-7294, Vol.24, pp.1-7, 2012
35.Piotrowski L., Augustyniak B., Chmielewski M., Kowalewski Z.L., On the possibility of application of magnetoacoustic emission for the assessment of plastic deformation level in ferrous materials, IEEE TRANSACTIONS ON MAGNETICS, ISSN: 0018-9464, Vol.47, pp.1-5, 2011
36.Rojek J., Pietrzak K., Chmielewski M., Kaliński D., Nosewicz S., Discrete Element Simulation of Powder Sintering, COMPUTER METHODS IN MATERIALS SCIENCE / INFORMATYKA W TECHNOLOGII MATERIAŁÓW, ISSN: 1641-8581, Vol.11, No.1, pp.68-73, 2011
Abstract:

This paper presents numerical modelling of powder sintering. The numerical model introduced in this work employs the discrete element method which assumes that material can be modelled by a large assembly of discrete elements (particles) of spherical shape interacting among one another. Modelling of sintering requires introduction of the cohesive interaction among particles representing inter-particle sintering forces. Numerical studies of sintering have been supplemented with experimental studies which provided data for calibration and validation of the model. In the laboratory tests evolution of microstructure and density during sintering have been studied. Comparison of numerical and experimental results shows a good performance of the numerical model developed.

Keywords:

powder sintering, powder metallurgy, simulation, discrete element method

Affiliations:
Rojek J.-IPPT PAN
Pietrzak K.-IPPT PAN
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Kaliński D.-other affiliation
Nosewicz S.-IPPT PAN
37.Piotrowski L., Augustyniak B., Chmielewski M., Kowalewski Z.L., Multiparameter analysis of the Barkhausen noise signal and its application for the assessment of a plastic deformation level in the 13HMF grade steel, MEASUREMENT SCIENCE AND TECHNOLOGY, ISSN: 0957-0233, Vol.21, No.11, pp.115702-1-7, 2010
Abstract:

The paper presents the results of multiparameter analysis of Barkhausen noise (BN) signal properties. In addition to the commonly used quantifiers of the BN signal, such as amplitude, integral of the BN envelope or results of pulse count analysis, we propose an additional analysis based on the change in magnetizing current amplitude. As it turns out the character of the change of the BN signal (as a function of the plastic deformation level) measured for various magnetizing currents differs significantly. Being so, a comparison of the results obtained for at least two magnetizing intensities gives a much better description of a plastic deformation level. In addition to that we observe two monotonic changes in the BN signal properties - a systematic shift of the BN signal peak position and the increase in the frequency for which the maximum in the BN FFT spectra occurs.

Keywords:

Barkhausen effect, plastic deformation, nondestructive evaluation

Affiliations:
Piotrowski L.-other affiliation
Augustyniak B.-Gdansk University of Technology (PL)
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Kowalewski Z.L.-IPPT PAN
38.Węglewski W., Chmielewski M., Kaliński D., Pietrzak K., Basista M., Thermal residual stresses generated during processing of Cr/Al2O3 composites and their influence on macroscopic elastic properties, Advances in Science and Technology, ISSN: 1662-0356, DOI: 10.4028/www.scientific.net/AST.65.27, Vol.65, pp.27-32, 2010
Abstract:

This work is focused on the modeling of thermal stresses induced during the fabrication of the metal/ceramic composites. On example of Cr-Al2O3 composite processed by powder metallurgy, thermal stresses after fabrication are determined by FEM model for different contents of metal and ceramic phases. Numerical model of microcracking induced by thermal stresses is then proposed and applied to compute the overall elastic properties of the damaged composite. Comparison of the model predictions with the measur ed data for Young's modulus is presented.

Keywords:

Cr-Al2O3 composite, mechanical properties, thermal stress modeling, microcracking, Young’s modulus modeling

Affiliations:
Węglewski W.-IPPT PAN
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Kaliński D.-other affiliation
Pietrzak K.-IPPT PAN
Basista M.-IPPT PAN
39.Chmielewski M., Pietrzak K., Kaliński D., Strojny A., Processing and thermal properties of Cu-AlN composites, Advances in Science and Technology, ISSN: 1662-0356, DOI: 10.4028/www.scientific.net/AST.65.100, Vol.65, pp.100-105, 2010
Abstract:

Heat transfer by conduction is involved in the use of heat sinks dissipitating heat from electronic devices. Effective transfer of heat requires using materials of high thermal conductivity. In addition, it requires appropriate values of thermal expansion, matched to the semiconductor materials, high purity of materials used and good contact between bonded elements across which heat transfer occurs. The conventional materials are not able to fulfil still raising and complex requirements. The solutions of this problem could be using the composites materials, where the combinations of different properties is possible to use. This study presents the technological tests and the analysis of correlation between processing parameters and the properties of copperaluminium nitride composites. Composite materials were obtained by mixing in planetary ball mill and then densified using the sintering under pressure or hot pressing method. The microstructure of obtained composite materials using optical microscopy and scanning electron microscopy were analyzed. Coefficient of thermal expansion (CTE) and thermal conductivity (TC) were investigated depending on the process conditions

Keywords:

Composite Material, Hot-Pressing, Sintering, Thermal Conductivity (TC), Thermal Diffusivity, Thermal Expansion Coefficient

Affiliations:
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Pietrzak K.-IPPT PAN
Kaliński D.-other affiliation
Strojny A.-Institute of Electronic Materials Technology (PL)
40.Augustyniak B., Chmielewski M., Piotrowski L., Kowalewski Z.L., Comparison of properties of magnetoacoustic emission and mechanical Barkhausen effects for P91 steel after plastic flow and creep, IEEE TRANSACTIONS ON MAGNETICS, ISSN: 0018-9464, DOI: 10.1109/TMAG.2008.2002525, Vol.44, pp.3273-3276, 2008
Abstract:

The correlation between magnetoacoustic emission intensity and mechanical Barkhausen effect intensity has been tested in the case of P91 steel having different microstructure states due to either plastic flow at room temperature or speeded-up creep, performed under stress 290 MPa at temperature 773 K. The plastic strain range for the first set of samples has been from 2.0% up to 10.5% and for the second one from 0.85% up to 10.0%. Both effects revealed analogous monotonous decrease of their intensities as a function of resulting plastic strain. The decrease was higher for plastic flow than for creep. Those results are well consistent with results of tensile tests of the as damaged samples.

Keywords:

Magnetic properties, Mechanical factors, Steel, Plastics, Creep, Testing, Temperature distribution, Microstructure, Performance evaluation, Stress

Affiliations:
Augustyniak B.-Gdansk University of Technology (PL)
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Piotrowski L.-other affiliation
Kowalewski Z.L.-IPPT PAN

Conference papers
1.Pietrzak K., Kaliński D., Chmielewski M., Chmielewski T., Włosiński W., Choręgiewicz K., Processing of intermetallics with Al2O3 or steel joints obtained by friction welding technique, ECerS XII, 12th Conference of the European Ceramic Society, 2011-06-19/06-23, Stockholm (SE), pp.1-4, 2011
Abstract:

The development of technologies for joining advanced materials is connected with an introduction of new materials and new applications of their bonds, to work in ever more difficult conditions. One of possibilities of obtaining this type of joints is using the friction welding technique. This paper presents the results of joining intermetallics (Fe-Al and Ni-Al type) with steel (S235JR) and ceramics (Al2O3) using friction welding technique. The focus of the investigations was selecting: appropriate rotational speed (10000-25000rpm) of joining elements, welding pressure and time (1500-4500ms) of its application and swelling time (1000-7000ms). The paper presents the results of microstructure investigations, investigations of microhardness (perpendicularly to joint surface) and mechanical properties (tensile strength).

Keywords:

friction welding, intermetallics, microstructure of joints, microhardness, tensile strength

Affiliations:
Pietrzak K.-IPPT PAN
Kaliński D.-other affiliation
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Chmielewski T.-other affiliation
Włosiński W.-other affiliation
Choręgiewicz K.-other affiliation
2.Pietrzak K., Jach K., Kaliński D., Chmielewski M., Morgiel J., Processing and Microstructure of Al2O3-Cu Composite Material Interpenetrating Network Type, Euro PM2011 Congress and Exhibition, 2011-10-09/10-12, Barcelona (ES), Vol.2, pp.1-6, 2011
Abstract:

Alumina/copper composites have been used where high thermal conductivity, high absorption and dissipation of heat, high resistance to thermal fatigue and good frictional wear resistance are required. This kind of composites may be applied in medicine, electronic and automotive industry. Both the physical and mechanical properties of this type of composites are strongly influenced by the properties of its individual constituents and, also, by the properties of interface layer between ceramic and metal. One of the solution, from the point of view of the best properties’ achievements (especially thermal, structural and shape stability), is the production of ceramic-metal composites with interpenetrating networks structure. They can be produced using porous alumina performs, which are infiltrated (pressure or pressureless) by molten metal or sintered with metallic powders. The subject of the presented paper is the development of the interpenetrating network Al2O3-Cu composites, processed by sintering porous ceramic perform (85 and 90% porosity) with copper powder. The paper presents the new developed technology, results of microstructure investigations, measurements of the selected physical and mechanical properties and the analysis of the influence of the processing conditions on the properties and interface morphology between ceramic and copper

Affiliations:
Pietrzak K.-IPPT PAN
Jach K.-Institute of Electronic Materials Technology (PL)
Kaliński D.-other affiliation
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Morgiel J.-Institute of Metallurgy and Materials Science, Polish Academy of Sciences (PL)
3.Rojek J., Pietrzak K., Chmielewski M., Kaliński D., Modelowanie spiekania proszków metalicznych metodą elementów dyskretnych, KomPlasTech 2010, XVII Konferencja Informatyka w Technologii Metali, 2010-01-10/01-13, Białka Tatrzańska (PL), pp.1-8, 2010
Abstract:

W artykule przedstawiono badania doświadczalne oraz modelowanie numeryczne procesu spiekania proszków metalicznych. W części eksperymentalnej pracy badano ewolucję mikrostruktury oraz gęstości spieku w trakcie procesu spiekania. Jako metodę modelowania wybrano metodę elementów dyskretnych, w której zakłada się, że materiał jest reprezentowany przez liczny zbiór elementów dyskretnych (cząstek) o kształcie sferycznym oddziałujących między sobą. Modelowanie spiekania wymaga wprowadzenia oddziaływania kohezyjnego między cząstkami reprezentującego naprężenia powstające między ziarnami w trakcie spiekania. W artykule przedstawiono wstępne wyniki numeryczne pokazujące ewolucję naprężenia w trakcie spiekania między dwoma ziarnami spiekanego proszku.

Keywords:

spiekanie, metalurgia proszków, związki międzymetaliczne, modelowanie, metoda elementów dyskretnych

Affiliations:
Rojek J.-IPPT PAN
Pietrzak K.-IPPT PAN
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Kaliński D.-other affiliation
4.Pietrzak K., Jach K., Kaliński D., Chmielewski M., Improving alumina wettabillity by modification of copper alloys chemical composition, PM2010, Powder Metallurgy World Congress and Exhibition, 2010-10-10/10-14, Florence (IT), Vol.2, pp.361-367, 2010

Conference abstracts
1.Chmielewski M., Pietrzak K., Strojny-Nędza A., Kaszyca K., Nosewicz S., Jarząbek D., The effect of nickel coating on the properties of Cu-SiC composites, EUROMAT 2017, European Congress and Exhibition on Advanced Materials and Processes, 2017-09-17/09-22, Thessaloniki (GR), pp.1, 2017
2.Nosewicz S., Rojek J., Maździarz M., Kowalczyk P., Wawrzyk K., Chmielewski M., Pietrzak K., Multiscale modeling of pressure-assisted sintering process, EUROMAT 2017, European Congress and Exhibition on Advanced Materials and Processes, 2017-09-17/09-22, Thessaloniki (GR), pp.1, 2017
3.Rojek J., Jurczak K., Nosewicz S., Lumelskyj D., Chmielewski M., Contact models for discrete element simulation of the power compaction in a hot pressing process, CMIS 2016, Contact Mechanics International Symposium, 2016-05-11/05-16, Warszawa (PL), pp.28-29, 2016
4.Nosewicz S., Jurczak K., Rojek J., Chmielewski M., Pietrzak K., Application of contact interaction of Hertz model to viscoelastic discrete element model of sintering, ISNNM, 14th International Symposium on Novel and Nano Materials, 2016-07-03/07-08, Budapeszt (HU), pp.119, 2016
5.Jurczak K., Rojek J., Nosewicz S., Lumelskyy D., Bochenek K., Chmielewski M., Pietrzak K., Modelowanie wstępnego prasowania proszków metodą elementów dyskretnych, KomPlasTech 2016, XXIII Konferencja Informatyka w Technologii Metali, 2016-01-17/01-20, Wisła (PL), pp.68, 2016
Abstract:

W niniejszym artykule zaprezentowano wyniki modelowania, zagęszczania proszku stanowiącego wstępny etap procesu prasowania na gorąco, metodą elementów dyskretnych opisaną w [1]. Modelowanie numeryczne zrealizowano metodą elementów dyskretnych, z wykorzystaniem kulistych cząstek. Badania skoncentrowano na mechanizmach zagęszczania proszku przy ciśnieniu 50 MPa oraz modelach odpowiednich przy zastosowanych warunkach procesu. Numeryczne symulacje wykonano z wykorzystaniem dwóch modeli: pierwszy - elastyczny Hertz-Mindlin-Deresiewicz, drugi - plastyczny Storakers, opisanych w pracy [2]. Wyniki symulacji numerycznych zostały porównane z wynikami laboratoryjnymi zagęszczania proszku NiAl w matrycy. W rezultacie otrzymano dużą zgodność wyników eksperymentalnych i numerycznych.

Keywords:

metoda elementów dyskretnych, modelowanie, zagęszczanie proszków, prasowanie

Affiliations:
Jurczak K.-IPPT PAN
Rojek J.-IPPT PAN
Nosewicz S.-IPPT PAN
Lumelskyy D.-IPPT PAN
Bochenek K.-IPPT PAN
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Pietrzak K.-other affiliation
6.Nosewicz S., Rojek J., Pietrzak K., Chmielewski M., Discrete element modelling of hot pressing process, EUROMAT 2015, European Congress and Exhibition on Advanced Materials and Processes, 2015-09-20/09-24, Warszawa (PL), pp.1, 2015
7.Basista M., Węglewski W., Bochenek K., Chmielewski M., Pietrzak K., Chromium-rhenium-alumina composites for powertrain application: Processing route, microstructure, properties and numerical modelling, EUROMAT 2015, European Congress and Exhibition on Advanced Materials and Processes, 2015-09-20/09-24, Warszawa (PL), pp.1, 2015
Abstract:

Chromium based composites reinforced with alumina particles combineenhanced thermal, oxidation and wear resistance with mechanical strength and hardness. Because of these valuable properties Cr/Al2O3 composites can be used e.g. in the automotive sector for elements of powertrain. Rhenium due to its good mechanical and thermal properties is primarily used as an admixture of nickel superalloys in the aerospace and chemical industries. In the present paper a powder metallurgy route was used to manufacture dense Cr/Re/Al2O3 bulk composites with rhenium admixture of 2vol% and 5vol%. Composites were processed by hot pressing (HP) and by spark plasma sintering (SPS) techniques. The density of the sintered composites exceeded 98% of the theoretical value. Microstructural characterisation revealed that a solid solution of rhenium in chromium was partially formed. Mechanical properties such as Young’s modulus, bending strength, hardness, plastic limit are promising so are oxidation and corrosion resistance. A numerical FE model was developed for the prediction of thermal residual stresses (TRS) and damage generated in the metal and ceramic phase during cooling from high sintering temperature down to room temperature. The model uses micro-CTimages of the real material microstructure as the input data. A good agreement of the simulation results for TRS and the measurements of by neutron diffraction was achieved. The obtained Cr/Re/Al2O3composites were already tested as demonstrators of valve seats in combustion engines and good preliminary results were reported.

Keywords:

Chromium-alumina MMC, rhenium admixture, powder metallurgy, thermal residual stresses, microCT FEM

Affiliations:
Basista M.-IPPT PAN
Węglewski W.-IPPT PAN
Bochenek K.-IPPT PAN
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Pietrzak K.-other affiliation
8.Jarząbek D., Chmielewski M., Wojciechowski T., The measurement of the adhesion force between ceramic particles and metal matrix in ceramic reinforced-metal matrix composites, EUROMAT 2015, European Congress and Exhibition on Advanced Materials and Processes, 2015-09-20/09-24, Warszawa (PL), pp.1, 2015
Abstract:

This paper presents the method for measurement of the adhesion force and fracture strength of the interface between ceramic particles and metal matrix in ceramic reinforced-metal matrix composites. Three samples with the following Cu to Al 2 O 3 ratio (in vol.%) were prepared: 98.0Cu/2.0Al 2 O 3 , 95.0Cu/5.0Al 2 O 3 and 90Cu/10Al 2 O 3 . Furthermore, microwires which contain a few ceramic particles were produced by means of electro etching. The microwires with clearly exposed interface were tested with use of the microt ensile tester (Fig. 1). The microtensile tester consists of two stages, to which two endings of the microwire are fixed. The first stage is able to measure force with the precision equal to 0.1 mN. The microwires usually break exactly at the interface between the metal matrix and ceramic particle. The force and the interface area were carefully measured and then the fracture strength of the interface was determined. The strength of the interface between ceramic particle and metal matrix was equal to 59 ±8 MPa and 59±11 MPa in the case of 2% and 5% Al 2 O 3 to Cu ratio, respectively. On the other hand, it was significantly lower (38±5 MPa) for the wires made of composite with 10% Al2O3

Affiliations:
Jarząbek D.-IPPT PAN
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Wojciechowski T.-Institute of Physics, Polish Academy of Sciences (PL)
9.Jarząbek D.M., Chmielewski M., Wojciechowski T., The measurement of the adhesion force between ceramic particles and metal matrix in ceramic reinforced-metal matrix composites, Nanomechanical Testing in Materials Research and Development V, 2015-10-04/10-09, Albufeira (PT), pp.1, 2015
10.Augustyniak B., Piotrowski L., Chmielewski M., Kowalewski Z.L., Makowska K., Case study on damage detection possibility in P91 and 40HNMA steels using magnetic NDT techniques, DAS 30, 30th Danubia-Adria-Symposium on Advances in Experimental Mechanics, 2013-09-25/09-28, Primosten (HR), Vol.1, pp.87-88, 2013
11.Nosewicz S., Rojek J., Pietrzak K., Chmielewski M., Numerical modeling of stresses in composites manufactured by powder metallurgy, ICMM3, 3rd International Conference on Material Modelling incorporating 13th European Mechanics of Materials Conference, 2013-09-08/09-11, Warszawa (PL), pp.133, 2013
12.Rojek J., Nosewicz S., Pietrzak K., Chmielewski M., Discrete element modelling of powder metallurgy processes, Particles 2013, III International Conference on Particle-based Methods, 2013-09-18/09-20, Stuttgart (DE), pp.1, 2013
13.Rojek J., Nosewicz S., Pietrzak K., Chmielewski M., Simulation of powder sintering using a discrete element method, VII International Symposium on Mechanics of Materials and Structures, 2013-06-03/06-06, Augustów (PL), pp.59-60, 2013
14.Rojek J., Nosewicz Sz., Pietrzak K., Chmielewski M., Kaliński D., Discrete element simulation of powder metallurgy manufacturing process of metal-ceramic composites, ECCOMAX 2012, 6th European Congress on Computational Methods in Applied Sciences and Engineering, 2012-09-10/09-14, Wiedeń (AT), pp.1-2, 2012
15.Nosewicz Sz., Rojek J., Pietrzak K., Chmielewski M., Kaliński D., Kačianauskas R., Discrete Element Modelling of Solid State Sintering Process of Metal-Ceramic Composite, SolMech 2012, 38th Solid Mechanics Conference, 2012-08-27/08-31, Warszawa (PL), pp.172-173, 2012
16.Rojek J., Nosewicz S., Pietrzak K., Chmielewski M., Kaliński D., Modelling of powder sintering using the discrete element method, CMM 2011, 19th International Conference on Computer Methods in Mechanics, 2011-05-09/05-12, Warszawa (PL), pp.241-1-2, 2011
17.Rojek J., Pietrzak K., Chmielewski M., Kaliński D., Discrete element modelling of powder sintering, SolMech 2010, 37th Solid Mechanics Conference, 2010-09-06/09-10, Warszawa (PL), pp.64-65, 2010
18.Rojek J., Pietrzak K., Chmielewski M., Kaliński D., Constitutive modelling of sintering processes using the discrete element method, Workshop on Constitutive Modeling in Applications for Industrial Processes, 2010-09-01/09-03, Kraków (PL), pp.1-2, 2010