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Affiliation to IPPT PAN

1.Kowalczyk-Gajewska K., Pieczyska E.A., Golasiński K., Maj M., Kuramoto S., Furuta T., A finite strain elastic-viscoplastic model of Gum Metal, International Journal of Plasticity, ISSN: 0749-6419, DOI: 10.1016/j.ijplas.2019.02.017, Vol.119, pp.85-101, 2019
Kowalczyk-Gajewska K., Pieczyska E.A., Golasiński K., Maj M., Kuramoto S., Furuta T., A finite strain elastic-viscoplastic model of Gum Metal, International Journal of Plasticity, ISSN: 0749-6419, DOI: 10.1016/j.ijplas.2019.02.017, Vol.119, pp.85-101, 2019

Abstract:
A hyperelastic-viscoplastic model of Gum Metal is presented. The model is formulated in the large strain framework. The free energy function is postulated consisting of the hyperelastic and viscoplastic components. Original extension of the Neo-Hooke model with a power law component is proposed for hyperelasticity, which enables to describe a relatively large non-linear elastic regime observed for the alloy. Viscoplastic strain follows the Perzyna-type law with an overstress function. The model is implemented into the finite element method and used to simulate the Gum Metal response in multiple tension loading-unloading cycles. The results are compared with experimental outcomes. Good accordance of the simulation results and the available experimental data is obtained.

Keywords:
Large strain, Hyperelasto-viscoplasticity, Gum metal, Cyclic deformation

2.Kowalczyk-Gajewska K., Maździarz M., Effective stiffness tensor of nanocrystalline materials of cubic symmetry: The core-shell model and atomistic estimates, International Journal of Engineering Science, ISSN: 0020-7225, DOI: 10.1016/j.ijengsci.2019.103134, Vol.144, No.103134, pp.1-24, 2019
Kowalczyk-Gajewska K., Maździarz M., Effective stiffness tensor of nanocrystalline materials of cubic symmetry: The core-shell model and atomistic estimates, International Journal of Engineering Science, ISSN: 0020-7225, DOI: 10.1016/j.ijengsci.2019.103134, Vol.144, No.103134, pp.1-24, 2019

Abstract:
Anisotropic core-shell model of a nano-grained polycrystal, proposed recently for nanocrystalline copper, is applied to estimate elastic effective properties for a set of crystals of cubic symmetry. Materials selected for analysis differ in the lattice geometry (face-centered cubic vs. body-centered cubic) as well as the value of a Zener factor: a ratio of two shear moduli defining elastic anisotropy of a cubic crystal. The predictions are verified by means of the atomistic simulations. The dependence of the overall bulk and shear moduli on the average grain diameter is analysed. In the mean-field approach the thickness of the shell is specified by the cutoff radius of a corresponding atomistic potential, while the grain shell is isotropic and its properties are identified by molecular simulations performed for very small grains with approximately all atoms belonging to the grain boundary zone. It is shown that the core-shell model provides predictions of satisfactory qualitative and quantitative agreement with atomistic simulations. Performed study indicates that the variation of the bulk and shear moduli with the grain size changes qualitatively when the Zener anisotropy factor is smaller or greater than one.

Keywords:
Molecular statics, Elasticity, Polycrystal, Effective medium, Cubic symmetry

3.Kucharski S., Woźniacka S., Size Effect in Single Crystal Copper Examined with Spherical Indenters, METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, ISSN: 1073-5623, DOI: 10.1007/s11661-019-05160-w, pp.1-16, 2019
Kucharski S., Woźniacka S., Size Effect in Single Crystal Copper Examined with Spherical Indenters, METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, ISSN: 1073-5623, DOI: 10.1007/s11661-019-05160-w, pp.1-16, 2019

Abstract:
The increasing hardness with decreasing penetration depth, referred to as indentation size effect (ISE) was previously investigated experimentally and theoretically by many researchers, however the mechanisms responsible for ISE are still being discussed. Generally, ISE is related to the density of geometrically necessary dislocation stored within a small volume beneath the indenter tip. In this study ISE is investigated experimentally in a single crystal copper using spherical indenter tips of different radii. Some new aspects of ISE are shown: a qualitative change of shape of residual impression (pile-up/sink-in pattern) when tip radius or load is modified, an increase of maximum pop-in load with decrease of tip radius as well as the well-known increase of hardness when tip radius decreases are analyzed. As we observe a difference of the residual imprint morphology which depends on tip radius and load, we apply two methods of hardness estimation: true hardness and nominal hardness. The former is determined on the basis of direct measurement of the contact area while accounting for a specific pile-up pattern, while the latter is determined by measuring the contact area using residual penetration depth. We show that hardness–tip radius relationship has a linear form for the nominal hardness and bilinear form for the true hardness.

4.Frydrych K., Simulations of Grain Refinement in Various Steels Using the Three-Scale Crystal Plasticity Model, METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, ISSN: 1073-5623, DOI: 10.1007/s11661-019-05373-z, Vol.50, No.10, pp.4913-4919, 2019
Frydrych K., Simulations of Grain Refinement in Various Steels Using the Three-Scale Crystal Plasticity Model, METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, ISSN: 1073-5623, DOI: 10.1007/s11661-019-05373-z, Vol.50, No.10, pp.4913-4919, 2019

Abstract:
In this paper, the recently developed three-scale crystal plasticity model is applied to simulate microstructural evolution of austenitic and ferritic stainless steels subjected to large plastic strains. It is shown that the model is able to correctly predict both texture and misorientation angle distributions in the materials studied. Moreover, it can correctly capture the grain-refinement kinetics and the influence of the stacking fault energy. Finally, it is confirmed that the 3SCP model is a computationally attractive alternative for reliable modeling of microstructural evolutions in metals and alloys.

5.Mercier S., Kowalczyk-Gajewska K., Czarnota C., Effective behavior of composites with combined kinematic and isotropic hardening based on additive tangent Mori–Tanaka scheme, COMPOSITES PART B-ENGINEERING, ISSN: 1359-8368, DOI: 10.1016/j.compositesb.2019.107052, Vol.174, pp.107052-1-21, 2019
Mercier S., Kowalczyk-Gajewska K., Czarnota C., Effective behavior of composites with combined kinematic and isotropic hardening based on additive tangent Mori–Tanaka scheme, COMPOSITES PART B-ENGINEERING, ISSN: 1359-8368, DOI: 10.1016/j.compositesb.2019.107052, Vol.174, pp.107052-1-21, 2019

Abstract:
The goal of the present work is to propose a multi-scale approach for composite materials which accounts for kinematic hardening in the phases. For that purpose, the additive/sequential interaction rule and tangent linearization of viscoplastic response proposed for elastic–viscoplastic material can be extended in a straightforward manner. A two phase composite where each phase is elastic–viscoplastic is considered. The viscoplastic flow is governed by a ?2 flow theory with an overstress. To find the overall behavior of the composite, a Mori–Tanaka model is applied. Numerical validation of the proposition is carried out by considering a representative volume element with 30 inclusions. Various configurations have been tested: hard or soft inclusion cases with or without isotropic hardening. It is shown that the quality of the model predictions is not affected by the introduction of the kinematic hardening component in the local constitutive behavior. Namely, in most cases considered in the paper the overall stress–strain response as well as the average stress–strain response per phase is accurately estimated. It has been also verified that the obtained backstress components are consistent with the ones predicted by Finite element calculations with ABAQUS Software.

Keywords:
Elastic-viscoplasticity, Homogenization, Finite element, Metal matrix composite, Mori–Tanaka scheme, Kinematic hardening

6.Węglewski W., Krajewski M., Bochenek K., Denis P., Wysmołek A., Basista M., Anomalous size effect in thermal residual stresses in pressure sintered alumina-chromium composites, MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, ISSN: 0921-5093, DOI: 10.1016/j.msea.2019.138111, Vol.762, No.138111, pp.1-10, 2019
Węglewski W., Krajewski M., Bochenek K., Denis P., Wysmołek A., Basista M., Anomalous size effect in thermal residual stresses in pressure sintered alumina-chromium composites, MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, ISSN: 0921-5093, DOI: 10.1016/j.msea.2019.138111, Vol.762, No.138111, pp.1-10, 2019

Abstract:
This paper explores an anomalous size effect in thermal residual stresses occurring in the alumina matrix of Al2O3/Cr sintered composite upon varying the particle size of the chromium reinforcement. When a coarse chromium powder (45 µm mean particle size) is used the average residual stress in the alumina phase after cooling is compressive in accordance with the classical Eshelby solution. However, in the case of a fine chromium (5 µm mean particle size) it switches to tension. This effect, detected by photoluminescence piezospectroscopy, is also confirmed by X-ray and neutron diffraction experiments. As the classical micromechanics models are incapable to capture it, a finite element model is developed with the actual composite microstructure being reconstructed from the microtomography images. It is shown by numerical simulations that the anomalous size effect is associated with the complex microstructure of the composite fabricated with the fine chromium powder. It is also pointed out that the temperature dependence of the coefficients of thermal expansion of the matrix and the reinforcement affects the residual stress levels.

Keywords:
thermal residual stress; metal-ceramic composites; size effect; microcomputed tomography, finite element analysis

7.Bazarnik P., Nosewicz S., Romelczyk-Baishya B., Chmielewski M., Strojny-Nędza A., Maj J., Huang Y., Lewandowska M., Langdon T.G., Effect of spark plasma sintering and high-pressure torsion on the microstructural and mechanical properties of a Cu–SiC composite, MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, ISSN: 0921-5093, DOI: 10.1016/j.msea.2019.138350, Vol.766, pp.138350- , 2019
Bazarnik P., Nosewicz S., Romelczyk-Baishya B., Chmielewski M., Strojny-Nędza A., Maj J., Huang Y., Lewandowska M., Langdon T.G., Effect of spark plasma sintering and high-pressure torsion on the microstructural and mechanical properties of a Cu–SiC composite, MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, ISSN: 0921-5093, DOI: 10.1016/j.msea.2019.138350, Vol.766, pp.138350- , 2019

Abstract:
This investigation examines the problem of homogenization in metal matrix composites (MMCs) and the methods of increasing their strength using severe plastic deformation (SPD). In this research MMCs of pure copper and silicon carbide were synthesized by spark plasma sintering (SPS) and then further processed via high-pressure torsion (HPT). The microstructures in the sintered and in the deformed materials were investigated using Scanning Electron Microscopy (SEM) and Scanning Transmission Electron Microscopy (STEM). The mechanical properties were evaluated in microhardness tests and in tensile testing. The thermal conductivity of the composites was measured with the use of a laser pulse technique. Microstructural analysis revealed that HPT processing leads to an improved densification of the SPS-produced composites with significant grain refinement in the copper matrix and with fragmentation of the SiC particles and their homogeneous distribution in the copper matrix. The HPT processing of Cu and the Cu–SiC samples enhanced their mechanical properties at the expense of limiting their plasticity. Processing by HPT also had a major influence on the thermal conductivity of materials. It is demonstrated that the deformed samples exhibit higher thermal conductivity than the initial coarse-grained samples.

Keywords:
Copper, Silicon carbide, High-pressure torsion, Spark plasma sintering, Thermal conductivity

8.Levintant-Zayonts N., Starzyński G., Kopeć M., Kucharski S., Characterization of NiTi SMA in its unusual behaviour in wear tests, TRIBOLOGY INTERNATIONAL, ISSN: 0301-679X, DOI: 10.1016/j.triboint.2019.05.005, Vol.137, pp.313-323, 2019
Levintant-Zayonts N., Starzyński G., Kopeć M., Kucharski S., Characterization of NiTi SMA in its unusual behaviour in wear tests, TRIBOLOGY INTERNATIONAL, ISSN: 0301-679X, DOI: 10.1016/j.triboint.2019.05.005, Vol.137, pp.313-323, 2019

Abstract:
The manuscript presents experimental investigations of an unusual behaviour of shape memory alloys (NiTi) having different characteristic temperatures in wear test. The studies are focused on the different wear mechanism at varying loads and sliding times and include a description of the phenomena accompanying the wear process. The ball-on-plate reciprocating sliding wear tests were conducted on NiTi shape memory alloys against a sapphire ball. We show that the wear resistance of NiTi is affected by its specific stress-strain characteristic. The understanding of the tribological behaviour of NiTi, a knowledge of the course of wear and an examination of its mechanisms can enable an effective prevention of the destruction of devices components and prolong their safe working life.

Keywords:
Wear behaviour of NiTi SMA, Friction coefficient, Superelasticity, Shape memory effect

9.Kucharski S., Starzyński G., Contact of rough surfaces under normal and tangential loading, WEAR, ISSN: 0043-1648, DOI: 10.1016/j.wear.2019.203075, Vol.440-441, No.203075, pp.1-14, 2019
Kucharski S., Starzyński G., Contact of rough surfaces under normal and tangential loading, WEAR, ISSN: 0043-1648, DOI: 10.1016/j.wear.2019.203075, Vol.440-441, No.203075, pp.1-14, 2019

Abstract:
Contact between a deformable, random rough surface and a rigid flat counterpart was investigated experimentally and theoretically. In the experimental setup, two modes of rough surface flattening were performed, namely normal compression and sliding (tangential load) in presence of normal compression. The load-approach relationship and friction coefficient were measured. After unloading the surface, the topography was measured using scanning profilometry. The deformation of roughness zone, i.e. evolution of the real contact area (RCA), and roughness parameters were analysed. A model based on statistical analysis and a finite element solution was applied to predict the load–approach relationship. The numerical and experimental results were compared. The effect of friction coefficient was discussed.

Keywords:
Contact mechanics, Roughness, Normal load, Tangential load

10.Musiał S., Nowak M., Maj M., Stress field determination based on digital image correlation results, ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING, ISSN: 1644-9665, DOI: 10.1016/j.acme.2019.06.007, Vol.19, No.4, pp.1183-1193, 2019
Musiał S., Nowak M., Maj M., Stress field determination based on digital image correlation results, ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING, ISSN: 1644-9665, DOI: 10.1016/j.acme.2019.06.007, Vol.19, No.4, pp.1183-1193, 2019

Abstract:
The aim of this work was to determine the stress distribution during plastic deformation, based on the displacement field obtained using the digital image correlation (DIC) method. To achieve stress distribution, the experimentally measured displacement gradient and the elastoplastic material model with isotropic hardening were used. The proposed approach was implemented in the ThermoCorr program. The developed procedure was used to determine stress fields for uniaxial tension and simple shear processes, carried out on samples made of austenitic steel 304L. Both material parameters, such as the Young's modulus, Poisson's ratio, yield stress, and parameters of the hardening curve, were acquired experimentally. The macroscopic force obtained from the DIC-based stresses and its finite element analysis (FEA) equivalent were compared with that measured during the experiment. It was shown that the DIC-based approach gives more accurate results with respect to FEA, especially for a simple shear test, where FEA significantly overestimates the value of experimentally obtained macroscopic force.

Keywords:
Stress field determination, Digital image correlation (DIC), Finite element analysis (FEA), Elastoplastic constitutive model, Plastic work

11.Nosewicz S., Rojek J., Chmielewski M., Pietrzak K., Discrete Element Modeling of Intermetallic Matrix Composite Manufacturing by Powder Metallurgy, Materials, ISSN: 1996-1944, DOI: 10.3390/ma12020281, Vol.12, No.281, pp.1-18, 2019
Nosewicz S., Rojek J., Chmielewski M., Pietrzak K., Discrete Element Modeling of Intermetallic Matrix Composite Manufacturing by Powder Metallurgy, Materials, ISSN: 1996-1944, DOI: 10.3390/ma12020281, Vol.12, No.281, pp.1-18, 2019

Abstract:
This paper presents a numerical and experimental analysis of manufacturing of intermetallic ceramic composites by powder metallurgy techniques. The scope of the paper includes the formulation and development of an original numerical model of powder metallurgy of two-phase material within the framework of the discrete element method, simulations of powder metallurgy processes for different combinations of process parameters, and a verification of the numerical model based on own experimental results. Intermetallic-based composite NiAl–Al2O3 has been selected as representative material for experimental and numerical studies in this investigation. Special emphasis was given to the interactions between the intermetallic and ceramic particles by formulating the special model for adhesive contact bond. In order to properly represent a real microstructure of a two-phase sintered body, a discrete element specimen was generated using a special algorithm. Numerical validation showed the correct numerical representation of a sintered two-phase composite specimen. Finally, micromechanical analysis was performed to explain the macroscopic behavior of the sintered sample. The evolution of the coordination number, a number of equilibrium contacts, and the distribution of the cohesive neck size with respect to time are presented.

Keywords:
powder metallurgy; sintering; discrete element method; modeling; intermetallic matrix composites

12.Ryś M., Egner H., Energy equivalence based constitutive model of austenitic stainless steel at cryogenic temperatures, INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES, ISSN: 0020-7683, DOI: 10.1016/j.ijsolstr.2018.12.028, Vol.164, pp.52-65, 2019
Ryś M., Egner H., Energy equivalence based constitutive model of austenitic stainless steel at cryogenic temperatures, INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES, ISSN: 0020-7683, DOI: 10.1016/j.ijsolstr.2018.12.028, Vol.164, pp.52-65, 2019

Abstract:
In the present work the constitutive model of 316L and 304 stainless steel subjected to mechanical loading at cryogenic temperatures is derived. Three main coupled dissipative phenomena taking place in the material: plastic flow, plastic strain-induced transformation from the primary phase (γ) to the secondary phase (α′), and evolution of micro-damage are considered using a thermodynamically consistent framework. The approach based on total energy equivalence, originally developed for damaged materials, is here extended to modelling not only damage but also phase transformation, in a consistent manner. The proposed model is implemented numerically and validated by means of parametric studies, and by comparison with the experimental results. Very good qualitative and quantitative results are obtained.

Keywords:
Constitutive modelling, Plasticity, Damage, Phase transformation, Cryogenic temperatures

13.Lengiewicz J., Hołobut P., Efficient collective shape shifting and locomotion of massively-modular robotic structures, Autonomous Robots, ISSN: 0929-5593, DOI: 10.1007/s10514-018-9709-6, Vol.43, No.1, pp.97-122, 2019
Lengiewicz J., Hołobut P., Efficient collective shape shifting and locomotion of massively-modular robotic structures, Autonomous Robots, ISSN: 0929-5593, DOI: 10.1007/s10514-018-9709-6, Vol.43, No.1, pp.97-122, 2019

Abstract:
We propose a methodology of planning effective shape shifting and locomotion of large-ensemble modular robots based on a cubic lattice. The modules are divided into two groups: fixed ones, that build a rigid porous frame, and mobile ones, that flow through the frame.Mobile modules which flow out of the structure attach to the frame, advancing its boundary. Conversely, a deficiency of mobile modules in other parts of the boundary is corrected by decomposition of the frame. Inside the structure, appropriate module flow is arranged to transport the modules in a desired direction, which is planned by a special distributed version of a maximum flow search algorithm. The method engages a volume of modules during reconfiguration, which is more efficient than common surface-flow approaches. Also, the proposed interpretation as a flow in porous media with moving boundaries seems particularly suitable for further development of more advanced global reconfiguration scenarios. The theoretical efficiency of the method is assessed, and then partially verified by a series of simulations. The method can be possibly also applied to a wider class of modular robots, not necessarily cubic-lattice-based.

Keywords:
Modular robots, Self-reconfiguration, Maximum flow search, Programmable matter, Distributed algorithms

14.Minafò G., Rezaee-Hajidehi M., Giambanco G., A Mechanical Approach for Evaluating the Distribution of Confinement Pressure in FRP-Wrapped Rectangular Columns, JOURNAL OF ENGINEERING MECHANICS-ASCE, ISSN: 0733-9399, DOI: 10.1061/(ASCE)EM.1943-7889.0001673, Vol.145, No.12, pp.04019092-1-9, 2019
Minafò G., Rezaee-Hajidehi M., Giambanco G., A Mechanical Approach for Evaluating the Distribution of Confinement Pressure in FRP-Wrapped Rectangular Columns, JOURNAL OF ENGINEERING MECHANICS-ASCE, ISSN: 0733-9399, DOI: 10.1061/(ASCE)EM.1943-7889.0001673, Vol.145, No.12, pp.04019092-1-9, 2019

Abstract:
In recent decades, fiber reinforced polymer (FRP) wrapping has become a common technique to retrofit reinforced concrete (RC) columns. Numerous research works have sought to verify analytically and experimentally its effectiveness in terms of enhancement of axial load bearing capacity and ductility. These studies highlighted that in the case of sharp-cornered sections, the maximum allowable confinement pressure is limited by premature failure at corners and, consequently, stress in the FRP, as well as the distribution of the confinement pressure, is not uniform. The prediction of this phenomenon is not straightforward, and existing theoretical studies propose complex numerical simulations, whereas technical codes provide simplified or empirical relationships for its assessment. This paper presents an analytical model for the evaluation of the effective distribution of confinement pressure in FRP confined concrete members with rounded corners. The model allows considering the interaction with the concrete core and different brittle failure modes, including FRP rupture and debonding. It leads to determining the distribution of the confinement pressure along the section. Results are compared with those achieved by finite-element (FE) analyses and with numerical and experimental data available in the literature. Good agreement is obtained in all cases, showing the reliability of the proposed model.

Keywords:
Fiber reinforced polymer (FRP) wrapping, Corner radius, Confinement pressure, Brittle failure

15.Chmielewski M., Nosewicz S., Wyszkowska E., Kurpaska Ł., Strojny-Nędza A., Piątkowska A., Bazarnik P., Pietrzak K., Analysis of the micromechanical properties of copper-silicon carbide composites using nanoindentation measurements, CERAMICS INTERNATIONAL, ISSN: 0272-8842, DOI: 10.1016/j.ceramint.2019.01.257, Vol.45, No.7A, pp.9164-9173, 2019
Chmielewski M., Nosewicz S., Wyszkowska E., Kurpaska Ł., Strojny-Nędza A., Piątkowska A., Bazarnik P., Pietrzak K., Analysis of the micromechanical properties of copper-silicon carbide composites using nanoindentation measurements, CERAMICS INTERNATIONAL, ISSN: 0272-8842, DOI: 10.1016/j.ceramint.2019.01.257, Vol.45, No.7A, pp.9164-9173, 2019

Abstract:
The study presents a detailed analysis of the impact of the coating type of silicon carbide particles and its share by volume on the microstructure and micromechanical properties of Cu-SiC composites. In order to protect the carbide from decomposition during the manufacturing of the composites, the surface of SiC was modified via a plasma vapour deposition technique with a layer of metals (W, Cr, Ti and Ni). Composites with a variable share of the ceramic phase (10–50 %vol.) were obtained at a temperature of 950 °C using spark plasma sintering. An analysis of the structures of the composites, especially in the metal-ceramic boundary region, was conducted with the use of scanning and transmission electron microscopy. The mechanical properties of the composites in the Cu-interface-SiC system were studied via a nanoindentation technique. The comparison of the results of hardness and Young's modulus studies were completed in relation to the actual structures of the materials, which in turn made it possible to determine the impact of the interfacial structure on the global properties of the composite materials.

Keywords:
Copper-silicon carbide composites; Nanoindentation; SPS; Interface study

16.Jenczyk P., Gawrońska M., Dera W., Chrzanowska-Giżyńska J., Denis P., Jarząbek D.M., Application of SiC particles coated with a protective Ni layer for production of Ni/SiC co-electrodeposited composite coatings with enhanced tribological properties, CERAMICS INTERNATIONAL, ISSN: 0272-8842, DOI: 10.1016/j.ceramint.2019.08.063, Vol.45, pp.23540-23547, 2019
Jenczyk P., Gawrońska M., Dera W., Chrzanowska-Giżyńska J., Denis P., Jarząbek D.M., Application of SiC particles coated with a protective Ni layer for production of Ni/SiC co-electrodeposited composite coatings with enhanced tribological properties, CERAMICS INTERNATIONAL, ISSN: 0272-8842, DOI: 10.1016/j.ceramint.2019.08.063, Vol.45, pp.23540-23547, 2019

Abstract:
In this paper, the mechanical properties of composites consisting of electroplated Ni and co-electrodeposited SiC particles, coated with a thin protective layer of Ni, were studied. The protective layer was on the SiC particles prior to adding them to the electrolyte bath. It was demonstrated that due to the application of the protective layer it was possible to decrease sliding friction force, and improve the wear resistance, of the composite coatings in comparison with standard electroplated composite coatings made of Ni and co-electrodeposited pure SiC particles. Coating SiC particles with Ni was achieved by means of a PVD process. The main advantage of this step is avoiding oxidation of the surface of the particles during the contact with an electrolyte. Particles protected from oxidation lead to stronger interfacial bonding between the matrix and the reinforcement. Furthermore, better bonding protects the SiC particles from being extracted from the matrix by a counter-probe during friction and wear tests. The influence of the particle's concentration is studied. A smaller friction force and constant wear rate was observed.

Keywords:
Wear, Friction, Interfacial bonding strength, Metal matrix composites, Silicon carbide, Electrodeposited nickel

17.Krajewski M., Węglewski W., Bochenek K., Wysmołek A., Basista M., Optical measurements of thermal residual stresses in alumina reinforced with chromium, JOURNAL OF APPLIED PHYSICS, ISSN: 0021-8979, DOI: 10.1063/1.5083115, Vol.125, No.135104, pp.135104-1-135104-10, 2019
Krajewski M., Węglewski W., Bochenek K., Wysmołek A., Basista M., Optical measurements of thermal residual stresses in alumina reinforced with chromium, JOURNAL OF APPLIED PHYSICS, ISSN: 0021-8979, DOI: 10.1063/1.5083115, Vol.125, No.135104, pp.135104-1-135104-10, 2019

Abstract:
This work describes optical measurements of processing-induced thermal residual stresses in an alumina matrix reinforced with chromium particles. This ceramic-metal composite is manufactured by the powder metallurgy method comprising powder mixing in a planetary ball mill and consolidation by hot pressing. Two different chromium powders (5 μm and 45 μm mean particle size) are used, while the average
alumina particle size is kept constant (1 μm). The residual stresses in aluminum oxide are determined by applying two optical methods: photoluminescence piezo-spectroscopy (PLPS) and Raman spectroscopy (RS). Both experimental techniques reveal a chromium size effect in the residual stress measurements. When the fine chromium powder (5 μm) is used, the average residual stress in the ceramic phase is
tensile (unusual effect), whereas for the coarser chromium powder (45 μm) it becomes compressive. The PLPS measurements of the hydrostatic residual stress component in the ceramic phase yield the values of 0.290 and −0.130 GPa for samples with 5 μm and 45 μm chromium powders, respectively. In the RS experiments, the corresponding stress component in the alumina equals 0.351 GPa for the composite with 5 μm chromium and −0.158 GPa for that with 45 μm chromium powder. These values indicate that the residual stress in the alumina reinforced with 5 μm chromium is approximately twice higher than that in the alumina reinforced with 45 μm chromium. Finally, the validity of the results obtained with the optical techniques is confirmed by the neutron diffraction measurements.

18.Golasiński K., Pieczyska E., Maj M., Mackiewicz S., Staszczak M., Kowalewski Z., Urbański L., Zubko M., Takesue N., Anisotropy of Gum Metal analysed by ultrasonic measurement and digital image correlation, MATERIALS SCIENCE AND TECHNOLOGY, ISSN: 0267-0836, DOI: 10.1080/02670836.2019.1629539, pp.1-7, 2019
Golasiński K., Pieczyska E., Maj M., Mackiewicz S., Staszczak M., Kowalewski Z., Urbański L., Zubko M., Takesue N., Anisotropy of Gum Metal analysed by ultrasonic measurement and digital image correlation, MATERIALS SCIENCE AND TECHNOLOGY, ISSN: 0267-0836, DOI: 10.1080/02670836.2019.1629539, pp.1-7, 2019

Abstract:
The mechanical anisotropy of a multifunctional titanium alloy, Gum Metal, is investigated in this paper. The structural characterisation showed a strong <110> texture for Gum Metal, that is a result of the cold-swaging process applied during its manufacture. Gum Metal was treated as a transversally isotropic solid because of this texture. A significant difference from Young’s moduli of the alloy was detected from the ultrasonic measurement of parallel and perpendicular directions to the alloy swaging direction. Samples of Gum Metal cubes were compressed in two different orientations. During the deformation process, two perpendicular walls of each sample were monitored by two visible range cameras for further two-dimensional digital image correlation analysis, this confirmed a strong plastic anisotropy in Gum Metal.

Keywords:
Gum Metal, compression, mechanical anisotropy, digital image correlation, ultrasonic measurement, texture, titanium alloy, full-field deformation measurement

19.Frydrych K., Kowalczyk-Gajewska K., Prakash A., On solution mapping and remeshing in crystal plasticity finite element simulations: application to equal channel angular pressing, MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING, ISSN: 0965-0393, DOI: 10.1088/1361-651X/ab28e3, Vol.27, No.075001, pp.1-27, 2019
Frydrych K., Kowalczyk-Gajewska K., Prakash A., On solution mapping and remeshing in crystal plasticity finite element simulations: application to equal channel angular pressing, MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING, ISSN: 0965-0393, DOI: 10.1088/1361-651X/ab28e3, Vol.27, No.075001, pp.1-27, 2019

Abstract:
Microstructure evolution in crystalline materials subjected to different loading conditions is regularly studied using crystal plasticity finite element simulations. Accurate and reliable description of the microstructure, particularly in the case of large deformations, requires the usage of remeshing procedures and the mapping of the material state from the distorted mesh onto a new mesh. In this work, we evaluate three different solution mapping schemes, viz. closest point projection (CPP), sequential spherical linear interpolation (SLERP), and weighted spherical averages, all of which are based on the mapping of crystal plasticity variables. The results show that the mapping with CPP is generally acceptable, whilst the sequential SLERP is a more robust method with little additional computing effort.

Keywords:
crystal plasticity, solution mapping, remeshing, severe plastic deformation SPD, equal channel angular pressing ECAP

20.Nowak Z., Nowak M., Pęcherski R.B., Wiśniewski K., Widłaszewski J., Kurp P., Computational modeling of thermoplastic behavior of inconel 718 in application to laser-assisted bending of thin-walled tubes, INTERNATIONAL JOURNAL FOR MULTISCALE COMPUTATIONAL ENGINEERING, ISSN: 1543-1649, Vol.17, No.3, pp.317-338, 2019
Nowak Z., Nowak M., Pęcherski R.B., Wiśniewski K., Widłaszewski J., Kurp P., Computational modeling of thermoplastic behavior of inconel 718 in application to laser-assisted bending of thin-walled tubes, INTERNATIONAL JOURNAL FOR MULTISCALE COMPUTATIONAL ENGINEERING, ISSN: 1543-1649, Vol.17, No.3, pp.317-338, 2019

Abstract:
Laser-assisted tube bending is a promising manufacturing process which enables production of forms and shapes that cannot be obtained by purely mechanical bending. It is particularly suitable for high hardness and brittle materials, such as nickel alloys, ceramics and cast iron. In the current paper, mechanical loading and simultaneous heating by a moving laser beam are used in a controlled manner to obtain the required deformation. Experimental investigation of the Inconel 718 (IN718) alloy provides the basis for identification of parameters of two constitutive models, which encompass softening phenomena and the coupling of temperature and strains. Numerical simulations are conducted to provide more insight into the laser-assisted bending process of the IN718 thin-walled tubes. Temperature, stress and deformation fields are determined in sequentially coupled thermomechanical analyses using the FE code ABAQUS. Laser beam is modeled as a surface heat flux using the dedicated DFLUX procedure. The temperature field is used as a thermal load in the static general step, together with an external mechanical load. The process of tube bending is controlled by the displacement of the piston rod of the actuator, while the thrust force is the resulting value.

Keywords:
laser-assisted bending of tubes, identification of material parameters, numerical simulations

21.Widłaszewski J., Nowak M., Nowak Z., Kurp P., LASER-ASSISTED THERMOMECHANICAL BENDING OF TUBE PROFILES, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.24425/amm.2019.126268, Vol.64, No.1, pp.421-430, 2019
Widłaszewski J., Nowak M., Nowak Z., Kurp P., LASER-ASSISTED THERMOMECHANICAL BENDING OF TUBE PROFILES, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.24425/amm.2019.126268, Vol.64, No.1, pp.421-430, 2019

Abstract:
The subject of the work is the analysis of thermomechanical bending process of a thin-walled tube made of X5CrNi18-10 stainless steel. The deformation is produced at elevated temperature generated with a laser beam in a specially designed experimental setup. The tube bending process consists of local heating of the tube by a moving laser beam and simultaneous kinematic enforcement of deformation with an actuator and a rotating bending arm. During experimental investigations, the resultant force of the actuator and temperature at the laser spot are recorded. In addition to experimental tests, the bending process of the tube was modelled using the finite element method in the ABAQUS program. For this purpose, the tube deformation process was divided into two sequentially coupled numerical simulations. The first one was the heat transfer analysis for a laser beam moving longitudinally over the tube surface. The second simulation described the process of mechanical bending with the time-varying temperature field obtained in the first simulation. The force and temperature recorded during experiments were used to verify the proposed numerical model. The final stress state and the deformation of the tube after the bending process were analyzed using the numerical solution. The results indicate that the proposed bending method can be successfully used in forming of the thin-walled profiles, in particular, when large bending angles and a small spring-back effect are of interest.

Keywords:
laser forming, laser-assisted bending, numerical modelling