mgr inż. Kamil Bochenek

Zakład Mechaniki Materiałów (ZMM)
Pracownia Zaawansowanych Materiałów Kompozytowych (PZMK)
stanowisko: starszy specjalista
telefon: (+48) 22 826 12 81 wew.: 438
pokój: 145
e-mail: kboch

Ostatnie publikacje
1.Basista M., Węglewski W., Bochenek K., Poniżnik Z., Nowak Z., Micro-CT Finite Element Analysis of Thermal Residual Stresses and Fracture in Metal-Ceramic Composites, Advanced Engineering Materials, ISSN: 1438-1656, DOI: 10.1002/adem.201600725, Vol.19, No.8, pp.1600725-1-9, 2017

Streszczenie:

This paper presents a simple way of using X-ray micro-computed tomography (micro-CT) in numerical modeling of material properties of metal-ceramic composites. It shows step by step the proposed methodology with details of the finite element mesh creation, so that it can easily be reproduced by interested researchers. Two case studies are considered to show the proposed approach at work: i) determination of processing-induced residual stresses in hot pressed Cr/Al2O3 and NiAl/Al2O3 particulate composites and ii) determination of J-integral for an interpenetrating phase composite made of porous alumina preform infiltrated with molten copper. The method is straightforward and effective but has its limitations that are pointed out.

Afiliacje autorów:

Basista M.-IPPT PAN
Węglewski W.-IPPT PAN
Bochenek K.-IPPT PAN
Poniżnik Z.-IPPT PAN
Nowak Z.-IPPT PAN
25p.
2.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

Streszczenie:

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.

Słowa kluczowe:

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

Afiliacje autorów:

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
7p.
3.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

Streszczenie:

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.

Słowa kluczowe:

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

Afiliacje autorów:

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
4.Bochenek K., Basista M., Advances in processing of NiAl intermetallic alloys and composites for high temperature aerospace applications, PROGRESS IN AEROSPACE SCIENCES, ISSN: 0376-0421, DOI: 10.1016/j.paerosci.2015.09.003, Vol.79, pp.136-146, 2015

Streszczenie:

Over the last few decades intermetallic compounds such as NiAl have been considered as potential high temperature structural materials for aerospace industry. A large number of investigations have been reported describing complex fabrication routes, introducing various reinforcing/alloying elements along with theoretical analyses. These research works were mainly focused on the overcoming of main disadvantage of nickel aluminides that still restricts their application range, i.e. brittleness at room temperature. In this paper we present an overview of research on NiAl processing and indicate methods that are promising in solving the low fracture toughness issue at room temperature. Other material properties relevant for high temperature applications are also addressed. The analysis is primarily done from the perspective of NiAl application in aero engines in temperature regimes from room up to the operating temperature (over 1150 °C) of turbine blades.

Słowa kluczowe:

Nickel aluminide, Intermetallics, Turbine blades, Fracture toughness, Manufacturing techniques

Afiliacje autorów:

Bochenek K.-IPPT PAN
Basista M.-IPPT PAN
50p.
5.Węglewski W., Bochenek K., Basista M., Schubert Th., Jehring U., Litniewski J., Mackiewicz S., Comparative assessment of Young’s modulus measurements of metal-ceramic composites using mechanical and non-destructive tests and micro-CT based computational modeling, COMPUTATIONAL MATERIALS SCIENCE, ISSN: 0927-0256, DOI: 10.1016/j.commatsci.2013.04.007, Vol.77, pp.19-30, 2013

Streszczenie:

It is commonly known that the available non-destructive and mechanical methods of the Young modulus measurement yield different results. This paper presents comparison of the results of experimental determination and numerical modeling of the Young modulus of Cr–Al2O3–Re composites (MMC) processed by a powder metallurgical method (SPS). In the computational model a finite element analysis is combined with images of the real material microstructure obtained from micro-computed tomography (micro-CT). Experimental measurements were carried out by four testing methods: three-point bending, resonance frequency damping analysis (RFDA), ultrasonic pulse-echo technique, and scanning acoustic microscopy. The paper also addresses the issue which of the four experimental methods at hand gives results closest to the theoretical predictions of the micro-CT based FEM model.

Słowa kluczowe:

Finite element analysis (FEA), Micro-CT based FE model, Metal matrix composites, Elastic modulus, Mechanical and nondestructive techniques

Afiliacje autorów:

Węglewski W.-IPPT PAN
Bochenek K.-IPPT PAN
Basista M.-IPPT PAN
Schubert Th.-Fraunhofer Institut für Fertigungstechnik und Angewandte Materialforschung (DE)
Jehring U.-Fraunhofer Institut für Fertigungstechnik und Angewandte Materialforschung (DE)
Litniewski J.-IPPT PAN
Mackiewicz S.-IPPT PAN
30p.

Abstrakty konferencyjne
1.Basista M., Węglewski W., Bochenek K., Poniżnik Z., Modelling of thermal residual stresses and fracture in metal-ceramic composites, 4th Dresden Nanoanalysis Symposium, 2016-06-15/06-15, Dresden (DE), pp.6, 2016

Streszczenie:

In processing of metal-ceramic composites thermal residual stresses may result from different CTEs of the constituent materials, variable cooling rates inside the bulk material, or irregular pore shapes causing thermal stress concentrations.This paper investigates the interplay between material microstructure and processing-induced thermal residual stresses (TRS) in particulate bulk metal-matrix composites (MMC) and infiltrated phase composites (IPC) with the main objective to explore thecombined effect of TRS and microstructure on the macroscopic mechanical properties (E modulus, bending strength, fracture toughness) of the composite. The main focus is on numerical modelling of TRS, fracture toughness and effective elastic properties, while taking into account the real material microstructure from micro–computed tomography (micro-CT) experiments. The modelling methodology will be developed on examples ofa hot pressed chromium-alumina bulk MMCdoped with rheniumand on an IPC obtained by squeeze casting infiltrationof an alumina porous preform with molten Al alloyor Cu. Our interest in these particular compositesis motivated by their potential applications in transport and energy sectors. The paperwill includehighlights on the processingtechnologies used(HP, SPS, ceramic tape casting/squeeze casting infiltration), microscopic analysis of material microstructure with special focus on micro-CT scanning, measurements of TRS by neutron diffraction (ND) method, and numerical modelling of TRS by FEM using micro-CT images of real material microstructure. A numerical micro-CT based model developed to predict the TRS, Young’s modulus with account of TRS-induced damage of the ceramic phase will be shown (cf. Fig. 1). The grain size effect on TRS and Young’s modulus will be addressed. A good predictive capability of these TRS models was achieved which may become important considering the cost of beam time for ND experiments at neutron sources. Another model to be presented is concerned with micro-CT FEM modeling of fracture in infiltrated metal-ceramic composites. The model accounts for crack bridging toughening mechanism, large plastic deformations of metal ligaments, and matrix-ligament decohesion. Here the results on J integralin the case of compact-tensiontest specimen made of real interpentrating phase composite will be discussed. Finally, the large pool of obtained experimental data and modelling results will be wrapped up and conclusions will be drawn.

Słowa kluczowe:

metal-ceramic composites, processing, thermal residual stresses, Youngs' modulus, microCT imaging, numerical modelling

Afiliacje autorów:

Basista M.-IPPT PAN
Węglewski W.-IPPT PAN
Bochenek K.-IPPT PAN
Poniżnik Z.-IPPT PAN
2.Węglewski W., Basista M., Bochenek K., Numerical modeling of thermal residual stress in NiAl/Al2O3 composites: Effect on mechanical properties, 5th KMM-VIN Industrial Workshop: Multi-scale and multi-physics materials modeling for advanced industries, 2016-01-26/01-27, Madryt (ES), pp.1, 2016

Streszczenie:

In this paper a numerical model will be presented to investigate the influence of processing-induced thermal residual stresses (TRS) on the mechanical properties (E modulus, bending strength) in particulate bulk intermetallic-ceramic composites. The materials under consideration are hot pressed NiAl/20%Al2O3bulk composites sintered in different temperatures (1300 C deg. and 1400 C deg.). The reported research includes the processing of composites by powder metallurgy techniques (HP), microscopic analysis of material microstructure with special focus on micro-CT scanning, measurements of TRS by neutron diffraction (ND) method and numerical modeling of TRS by FEM based on micro-CT images of real material microstructure. Numerical micro-CT based models are proposed to predict the TRS and Young’s modulus with account of the TRS-induced damage of the ceramic phase. Our micro-CT based FEM models reproduce the TRS measurements with a good accuracy which may be an asset in applications having in mind the high cost of beam time for ND experiments at neutron sources. Finally, the experimental data and modeling results are compared to assess the TRS/microstructure effect on the Young’s modulus of the composites investigated.

Słowa kluczowe:

sintering, metal-matrix composites, thermal residual stresses, neutron diffraction, microCT based FEM model

Afiliacje autorów:

Węglewski W.-IPPT PAN
Basista M.-IPPT PAN
Bochenek K.-IPPT PAN
3.Jakubowska J., Węglewski W., Bochenek K., Kasiarova M., Dusza J., Basista M., Effect of microstructure and thermal residual stresses on fracture behaviour of metal-ceramic composites, AMT 2016, XXI Physical Metallurgy and Materials Science Conference - Advanced Materials and Technologies, 2016-06-05/06-08, Rawa Mazowiecka (PL), No.E07, pp.1, 2016

Streszczenie:

In this paper the influence of material microstructure and thermal residual stresses on the macroscopic fracture toughness, Young’s modulus and bending strength of metal-ceramic composites is studied.
The investigated materials were: (1) Cr/Al2O3 composites (MMC and cermets) with various proportions of the starting powders prepared by hot pressing, and (2) Al2O3/Al infiltrated composites with different volume fractions of the aluminium phase. The two groups of composites (particulate vs. infiltrated) were chosen to examine the effect in question because of their significantly different microstructure.
In the case of hot pressed Cr/Al2O3 composites local thermal residual stresses are generated during cooling from the sintering temperature to RT due to number of factors such as (i) differences in the coefficients of thermal expansion of the ceramic and metal phase, (ii) differences in cooling speeds in different parts of the material, and (iii) irregular shapes of pores causing stress concentrations.
The same problem of formation of thermal residual stresses occurs in the infiltrated Al2O3/Al composite with metal and ceramic phases forming spatially continuous networks throughout the structure (also called Interpenetrating Phase Composites, IPCs).
The fracture toughness and bending strength measurements were performed in a four-point bend test on SEVNB specimens. The microstructural characterization and crack growth analysis were done using scanning electron microscopy.
Our results show that the fracture toughness and other mechanical properties investigated in this study strongly depend on such microstructural features like the amount and distribution of metal and ceramic phase and the type of microstructure (particulate vs. infiltrated). On the other hand the stiffness of reinforcement and matrix, the volume fraction and the grain size of the reinforcement, difference in grain sizes between matrix and reinforcement have an effect on thermal residual stresses distribution, which in turn have an effect on the macroscopic fracture parameters and the crack growth path.

Słowa kluczowe:

thermal residual stresses, mechanical properties, powder metallurgy, interpenetrating phase composites

Afiliacje autorów:

Jakubowska J.-IPPT PAN
Węglewski W.-IPPT PAN
Bochenek K.-IPPT PAN
Kasiarova M.-Institute of Materials Research, Slovak Academy of Sciences (SK)
Dusza J.-Institute of Materials Research, Slovak Academy of Sciences (SK)
Basista M.-IPPT PAN
4.Węglewski W., Basista M., Bochenek K., Numerical modelling of the effect of thermal residual stress on mechanical properties of metal-ceramic composites, ECCOMAS 2016, European Congress on Computational Methods in Applied Sciences and Engineering, 2016-06-05/06-10, Hersonissos (GR), pp.1, 2016

Streszczenie:

In this paper a numerical model will be presented to investigate the influence of processing-induced thermal residual stresses (TRS) on the fracture (fracture toughness) and mechanical properties (E modulus, bending strength) in particulate bulk metal-ceramic composites. The materials under consideration are hot pressed chromium-alumina bulk composites with different content of alumina (30, 60 and 90 vol. %) and with two different starting sizes of chromium particles to show how the microstructure can influence on the level of TRS.
The reported research includes the processing of composites by powder metallurgy techniques (HP), microscopic analysis of material microstructure with special focus on micro-CT scanning, measurements of TRS by neutron diffraction (ND) method and numerical modelling of TRS by FEM based on micro-CT images of real material microstructure [1-3].
Spatial distributions of TRS measured by ND are considered when interpreting the results of KIC measurements in a four point bending test. Numerical micro-CT based models are proposed to predict the TRS, Young’s modulus and bending strength with account of the TRS-induced damage of the ceramic phase. Our micro-CT based FEM models reproduce the TRS measurements with a good accuracy which may be an asset in applications having in mind the high cost of beam time for ND experiments at neutron sources. Finally, the experimental data and modelling results are compared to assess the TRS/microstructure effect on the fracture toughness of the composites investigated.

[1] W. Weglewski, M. Basista, M. Chmielewski, K. Pietrzak Modeling of thermally induced damage in the processing of Cr–Al2O3 composites. Compos. Part B (2012) 255–264.
[2] W. Weglewski, K. Bochenek, M. Basista, T. Schubert, U. Jehring, J. Litniewski, S. Mackiewicz, Comparative assessment of Young's modulus measurements of metal–ceramic composites using mechanical and non-destructive tests andmicro-CT based computational modeling, Comput. Mater. Sci. 77 (2013) 19–30.
[3] W.Węglewski, M. Basista, A. Manescu, M. Chmielewski, K. Pietrzak, T. Schubert, Effect of grain size on thermal residual stresses and damage in sintered chromium–alumina composites: measurement and modelling, Compos. Part B 67 (2014) 119–124.

Słowa kluczowe:

processing of metal-matrix composites, ceramics, thermal residual stresses, neutron diffraction, microCT FEM

Afiliacje autorów:

Węglewski W.-IPPT PAN
Basista M.-IPPT PAN
Bochenek K.-IPPT PAN
5.Bochenek K., Basista M., Węglewski W., Hot pressed nickel aluminide materials with various dopant elements for high temperature regimes, Junior EUROMAT 2016, 13th FEMS Junior Euromat 2016 - The Major Event for Young Material Scientists, 2016-07-10/07-14, Lausanne (CH), pp.1, 2016

Streszczenie:

The nickel aluminide base composites are considered to be potentially interesting high temperature structural materials for aerospace industry due to their low density (5.9 g/cm3), high thermal conductivity (76 W/mK) and good corrosion and oxidation resistance. However, it is well-known that the main reason limiting this material's application in aerospace industry is related to its low fracture toughness and low ductility at room temperature. Research works on this subject have been carried out by various scientists throughout the world for more than four decades now. After initially high expectations, followed by rather disappointing results reported some 15 years ago, the recent progress in processing technologies in the context of fracture toughness levels is, indeed, remarkable. However, application of this structural material in real working conditions is still to be confirmed, [1].The composite materials investigated in this study were manufactured by powder metallurgy technique. The primary target was to obtain low density nickel aluminide bulk materials with enhanced fracture toughness, flexural strength and high oxidation resistance. The powders of NiAl were mixed in a planetary ball mill with various volume fractions of aluminum oxide, chromium and rhenium. Sintering was conducted in a hot press under the pressure of 30 MPa at 1400oC. Mechanical properties, microstructure and cyclic oxidation at 900oC, 1100oC, 1300oC were investigated. A promising improvement of flexural strength and fracture toughness were observed for each chemical composition. The highest enhancements were measured for the composite with 0.6 at.% addition of rhenium, where the flexural strength increasedfrom the reference level of 428 MPa (pure NiAl) to 808MPa. The oxidation tests showed predominantly high oxidation resistance due to formation of a thin oxide layer preventing significant mass losses. The oxidation experiment was limited to 150 cycles of 1 h duration, hence further tests are necessary to make the final assessment of the oxidation behavior.The second major problem investigated in this paper were thermal residual stresses (TRS) induced in the sintered composites during cooling from high sintering temperature to room temperature, due to CTE mismatch of the constituent materials. The effects of TRS on fracture parameters and other mechanical properties (E modulus, bending strength) were examined experimentally and modelled numerically using micro-CT based FE meshes mimicking the material microstructure. Our micro-CT based FEM models reproduce the TRS measurements by neutron diffraction with good accuracy, which may be an asset for engineering applications considering the high cost of beam time at the neutron sources.

Słowa kluczowe:

Intermetallics, nickel-aluminides, turbine blades

Afiliacje autorów:

Bochenek K.-IPPT PAN
Basista M.-IPPT PAN
Węglewski W.-IPPT PAN
6.Bochenek K., Węglewski W., Basista M., The microstructure, mechanical properties and oxidation resistance of nickel aluminide based composites with various dopant elements for high temperature aerospace applications, KMM-VIN IW6, 6th KMM-VIN Industrial Workshop “Innovative Material Solutions for Transport Applications”, 2016-04-07/04-08, Hatfield (GB), pp.1, 2016

Streszczenie:

Intermetallic compounds such as NiAl manifest an attractive combination of mechanical and physical properties– low dens ity (5.9g/cm 3 ), high melting point (1676 o C), high thermal stability along with good oxidation and corrosion resistance. This has resulted in their numerous non-structural applications such as thermal barrier coatings, but no successful structural application of NiAl has been reported yet. This is caused by its low ductility and poor fracture toughness (<5MPa√m ) at room temperature along with an insufficient impact resistance. There has been a lot of work done already in order to improve NiAl properties and implement this material in aeroengines. The results are very promising, but till now there has been no reported successful application of NiAl - based bulk materials in real in - service conditions [1 - 2 ].

Słowa kluczowe:

NiAl intermetallics, microstructure, flexural strength, fracture toughness, oxidation resistance, aeroengines

Afiliacje autorów:

Bochenek K.-IPPT PAN
Węglewski W.-IPPT PAN
Basista M.-IPPT PAN
7.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

Streszczenie:

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.

Słowa kluczowe:

metoda elementów dyskretnych, modelowanie, zagęszczanie proszków, prasowanie

Afiliacje autorów:

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
8.Basista M., Węglewski W., Bochenek K., Influence of material microstructure and thermal residual stresses on macroscopic fracture parameters and elastic properties of metal-ceramic composites, THERMEC’2016, International Conference on Processing & Manufacturing of Advanced Materials, 2016-05-29/06-03, Graz (AT), pp.93-94, 2016

Streszczenie:

Th is paper investigates the interplay between material microstructure and processing - induced thermal residual stresses (TRS) in particulate bulk MMC’ s with the main objective to explore their combined effect on the macroscopic fracture toughness and material properties (E modulus, bending strength) of the composite. The materials under consideration are hot pressed chromium - alumina bulk composites doped with rhenium, the use of which is motivated by their potential applications in transport and energy sectors. The reported research includes the processing of MMC by powder metallurgy techniques (HP and SPS), microscopic analysis of material microstructure with special focus on micro - CT scanning, measurements of TRS by neutron diffraction (ND) method and numerical modelling of TRS by FEM based on micro - CT images of real material microstructure. Several compositions of Cr(Re)/Al 2 O 3 system and different particle sizes were used in the sintering process to assess the effect of microstructure on the TRS. Spatial distributions of TRS measured by ND are taken as supporting information when interpreting the results of K IC measurements in a four point bending test. Numerical micro - CT based models were developed to predict the TRS, Young’s modulus and bending strength with account of TRS - induced damage of the ceramic phase of MMCs. A good predictive capability of these TRS models was achieved which may become important considering the cost of beam time for ND experiments at neutron sources. Finally, the large pool of experimental data and modelling results is discussed and the conclusions are drawn as to the TRS/microstructure effect on the fracture toughness of the MMCs in question.

Słowa kluczowe:

thermal residual stress, metal-ceramic composites, fracture toughness, microCT FEM

Afiliacje autorów:

Basista M.-IPPT PAN
Węglewski W.-IPPT PAN
Bochenek K.-IPPT PAN
9.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

Streszczenie:

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.

Słowa kluczowe:

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

Afiliacje autorów:

Basista M.-IPPT PAN
Węglewski W.-IPPT PAN
Bochenek K.-IPPT PAN
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Pietrzak K.-other affiliation