dr hab. inż. Michał Basista

Zakład Mechaniki Materiałów (ZMM)
Pracownia Zaawansowanych Materiałów Kompozytowych (PZMK)
stanowisko: profesor nadzwyczajny
telefon bezpośredni: (+48) 22 828 53 74
telefon: (+48) 22 826 12 81 wew.: 212
pokój: 143
e-mail: mbasista

Doktorat
1985Równania konstytutywne i ocena nośności granicznej ośrodków ze wstępną anizotropią struktury 
promotor -- prof. dr hab. inż. Wojciech Nowacki, IPPT PAN
418 
Habilitacja
2002Micromechanical and lattice modeling of brittle damage 
Promotor prac doktorskich
1.2009-01-22Węglewski Witold  Modelowanie zniszczenia betonu wywołanego korozją siarczanową623
 

Ostatnie publikacje
1.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
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

30p.
2.Kuśnierczyk K., Basista M., Recent advances in research on magnesium alloys and magnesium – calcium phosphate composites as biodegradable implant materials, JOURNAL OF BIOMATERIALS APPLICATIONS, ISSN: 0885-3282, DOI: 10.1177/0885328216657271, Vol.31, No.6, pp.878-900, 2017
Kuśnierczyk K., Basista M., Recent advances in research on magnesium alloys and magnesium – calcium phosphate composites as biodegradable implant materials, JOURNAL OF BIOMATERIALS APPLICATIONS, ISSN: 0885-3282, DOI: 10.1177/0885328216657271, Vol.31, No.6, pp.878-900, 2017

Abstract:
Magnesium alloys are modern biocompatible materials suitable for orthopaedic implants due to their biodegradability in biological environment. Many studies indicate that there is a high demand to design magnesium alloys with controllable in vivo corrosion rates and required mechanical properties. A solution to this challenge can be sought in the development of metal matrix composites based on magnesium alloys with addition of relevant alloying elements and bioceramic particles. In this study, the corrosion mechanisms along with corrosion protection methods in magnesium alloys are discussed. The recently developed magnesium alloys for biomedical applications are reviewed. Special attention is given to the newest research results in metal matrix composites composed of magnesium alloy matrix and calcium phosphates, especially hydroxyapatite or tricalcium phosphate, as the second phase with emphasis on the biodegradation behavior, microstructure and mechanical properties in view of potential application of these materials in bone implants.

Keywords:
Biomaterials, biodegradable, metal matrix composites, magnesium alloys, corrosion, hydroxyapatite, bone repair

25p.
3.Poniżnik Z., Nowak Z., Basista M., Numerical modeling of deformation and fracture of reinforcing fibers in ceramic–metal composites, INTERNATIONAL JOURNAL OF DAMAGE MECHANICS, ISSN: 1056-7895, DOI: 10.1177/1056789515611945, Vol.26, No.5, pp.711-734, 2017
Poniżnik Z., Nowak Z., Basista M., Numerical modeling of deformation and fracture of reinforcing fibers in ceramic–metal composites, INTERNATIONAL JOURNAL OF DAMAGE MECHANICS, ISSN: 1056-7895, DOI: 10.1177/1056789515611945, Vol.26, No.5, pp.711-734, 2017

Abstract:
This paper is concerned with numerical modeling of deformation and fracture of a metal ligament bridging the crack faces in ceramic–metal composites, as a prerequisite for the determination of the J integral for composites with interpenetrating microstructure. A finite element model is proposed of an elasto-plastic crack-reinforcing fiber undergoing large plastic deformations and progressive debonding from the elastic matrix through a cohesive matrix–fiber interface. The σ-u relationships are derived first in the case of pullout of an elasto-plastic fiber embedded in an elastic matrix and then in uniaxial tension of the elasto-plastic fiber bridging the crack faces in elastic matrix. The obtained numerical results are discussed and compared with the theoretical predictions reported by other authors.

Keywords:
Ceramic–metal composites, fracture modeling, crack bridging, fiber pullout, cohesive interface, fiber debonding, finite element simulations

4.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
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

35p.
5.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, pp.1-9, 2016
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, pp.1-9, 2016

Abstract:
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.

25p.
6.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
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

Abstract:
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.

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

50p.
7.Basista M., KMM-VIN AISBL Europejski Instytut Wirtualny Materiałów Wielofunkcyjnych, Materiały Kompozytowe, ISSN: 2084-1949, Vol.4, pp.48-51, 2015
Basista M., KMM-VIN AISBL Europejski Instytut Wirtualny Materiałów Wielofunkcyjnych, Materiały Kompozytowe, ISSN: 2084-1949, Vol.4, pp.48-51, 2015

Abstract:
Współczesne modele prowadzenia badań naukowych i prac rozwojowych w dziedzinie zaawansowanych materiałów konstrukcyjnych i funkcjonalnych wymagają współpracy i integracji zespołów badawczych o uzupełniających się kompetencjach w zakresie metod wytwarzania materiałów, charakteryzacji mikrostruktury, badań właściwości i modelowania. Aby można było myśleć o praktycznym wykorzystaniu wyników badań i innowacjach przemysłowych z nich wynikających konieczny jest aktywny udział przemysłu już na wczesnym etapie powstawania koncepcji projektu, następnie podczas jego realizacji, a zwłaszcza na etapie weryfikacji uzyskanych wyników na demonstratorach i liniach pilotażowych.

Keywords:
Europejski Instytut Wirtualny KMM-VIN AISBL, zaawansowane materiały, współpraca europejska

8.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
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

40p.
9.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
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

Abstract:
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.

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

30p.
10.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
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

7p.
11.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
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

45p.
12.Basista M., Poniżnik Z., Modelling of effective elastic properties and crack bridging in metal-ceramic interpenetrating phase composites, World Journal of Engineering, Vol.7, pp.95-96, 2010
Basista M., Poniżnik Z., Modelling of effective elastic properties and crack bridging in metal-ceramic interpenetrating phase composites, World Journal of Engineering, Vol.7, pp.95-96, 2010

Abstract:
The metal-ceramic interpenetrating phase composites (IPC) are usually processed by pressure assisted or pressureless infiltration of molten metals into porous ceramic performs. They have characteristic microstructure different than typical MMC or CMC with particulate or fiber reinforcement. The main difference is that both metal and ceramic phases are spatially continuous forming complementary 3D skeletons of non-zero stiffness. The uniform microstructure, enhanced mechanical and thermal properties are the main advantages of IPC. A state-of-the art in fracture and damage modelling of IPC can be found in [1], while models of effective properties in [2] and [3]. The objective of this paper is twofold: (i) to model the effective elastic properties of IPC, and (ii) to model the fracture in IPC with the crack bridging being the major toughening mechanism. The developed models are verified on the example of Al2O3-Cu infiltrated composites.

[1] Basista M. and Weglewski W. (2006). Modelling of damage and fracture in ceramic-matrix composites – an overview, J. Theor. Appl. Mech., 44, 455-484.
[2] Feng X., Tian Z., Liu Y. and Yu S. (2004). Effective elastic and plastic properties of interpenetrating multiphase composites, Appl. Comp. Mater., 11, 33-55.
[3] Poniznik Z., Salit V., Basista M. and Gross D. (2008). Effective elastic properties of interpenetrating phase composites, Comp. Mat. Sci., 44, 813-820.

Keywords:
Interpenetrating phase composites, effective elastic properties, crack bridging

2p.
13.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
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

14.Basista M., Węglewski W., Chemically assisted damage of concrete: a model of expansion under external sulfate attack, INTERNATIONAL JOURNAL OF DAMAGE MECHANICS, ISSN: 1056-7895, Vol.18, pp.155-175, 2009
Basista M., Węglewski W., Chemically assisted damage of concrete: a model of expansion under external sulfate attack, INTERNATIONAL JOURNAL OF DAMAGE MECHANICS, ISSN: 1056-7895, Vol.18, pp.155-175, 2009

Abstract:
A micromechanical model is proposed to simulate the deformation of cementitious composites exposed to external sulfate attack. The model involves coupled physico-chemical processes of nonsteady diffusion with reaction, topo-chemical reaction of ettringite formation, expansion of ettringite inclusions, microcracking of hardened cement paste and percolation of sulfates through heavily deteriorated mortar. The Fick’s second law with reaction term is assumed to govern the transport of the sulfate ions. The Eshelby solution and the equivalent inclusion method are used to determine the eigenstrain of expanding ettringite crystals in microcracked hardened cement paste. The degradation of transport properties is studied in the effective medium and the percolation regime. An initial boundary value problem (2D) of expansion of a mortar specimen immersed in a sodium sulfate solution is solved and compared with available test data.

Keywords:
chemo-damage, micromechanics, concrete, microcracking, sulfate attack

32p.
15.Poniżnik Z., Salit V., Basista M., Gross D., Effective elastic properties of interpenetrating phase composites, COMPUTATIONAL MATERIALS SCIENCE, ISSN: 0927-0256, DOI: 10.1016/j.commatsci.2008.06.010, Vol.44, pp.813-820, 2008
Poniżnik Z., Salit V., Basista M., Gross D., Effective elastic properties of interpenetrating phase composites, COMPUTATIONAL MATERIALS SCIENCE, ISSN: 0927-0256, DOI: 10.1016/j.commatsci.2008.06.010, Vol.44, pp.813-820, 2008

Abstract:
Objective of this paper is to estimate the effective elastic properties of metal-ceramic interpenetrating phase composites (IPC). To this end, approximate analytical models such as Feng’s and Tuchinskii’s model were employed and checked against Voigt, Reuss, and Hashin–Shtrikman bounds. On the other hand, the overall elastic properties of IPC were determined by means of some numerical models suitable for the interpenetrating networks with model microstructures. A real Al2O3–Cu microstructure acquired from the computer tomography images was also used for numerical simulations.

Keywords:
Interpenetrating phase composites, Metal-ceramic composites, Effective elastic moduli, Finite element method, Micromechanics, Microstructure

16.Basista M., Węglewski W., Micromechanical modelling of sulphate corrosion in concrete: Influence of ettringite forming reaction, Theoretical and Applied Mechanics, ISSN: 1450-5584, DOI: 10.2298/TAM0803029B, Vol.35, No.1-3, pp.29-52, 2008
Basista M., Węglewski W., Micromechanical modelling of sulphate corrosion in concrete: Influence of ettringite forming reaction, Theoretical and Applied Mechanics, ISSN: 1450-5584, DOI: 10.2298/TAM0803029B, Vol.35, No.1-3, pp.29-52, 2008

Abstract:
Two micromechanical models are developed to simulate the expansion of cementitious composites exposed to external sulphate attack. The di®erence between the two models lies in the form of chemical reaction of the ettringite formation (through-solution vs. topochemical). In both models the Fick's second law with reaction term is assumed to govern the transport of the sulphate ions. The Eshelby solution and the equivalent inclusion method are used to determine the eigenstrain of the expanding ettringite crystals in microcracked hardened cement paste. The degradation of transport properties is studied in the efective medium and the percolation regime. An initial-boundary value problem (2D) of expansion of a mortar specimen immersed in a sodium sulphate solution is solved and compared with available test data. The obtained results indicate that the topochemical mechanism is the one capable of producing the experimentally observed amount of expansion.

Keywords:
chemo-damage, sulphate attack, topochemical reaction, through-solution reaction, ettringite, micromechanics, microcracking, percolation

17.Basista M., Węglewski W., Modelling of damage and fracture in ceramic-matrix composites, JOURNAL OF THEORETICAL AND APPLIED MECHANICS, ISSN: 1429-2955, Vol.44, No.3, pp.455-484, 2006
Basista M., Węglewski W., Modelling of damage and fracture in ceramic-matrix composites, JOURNAL OF THEORETICAL AND APPLIED MECHANICS, ISSN: 1429-2955, Vol.44, No.3, pp.455-484, 2006

Abstract:
This is a review paper on the existing approaches to modelling of discrete cracks (fracture) and diffuse microcracking (damage) in ceramic matrix composites under mechanical or thermal loading. The focus is on Ceramic Matrix Composites (CMC) with metal particle inclusions and on interpenetrating metal ceramic networks. The second phase in form of ceramic inclusions is not considered. The models of toughening mechanisms are discussed in considerable detail. Sections 2-5 deal with discrete cracks while Sections 6-9 with diffuse microcracking. The paper is concluded with identification of unresolved problems and topics for future research in the area of fracture and damage of CMC.

Keywords:
ceramic matrix composites, particles, interpenetrating networks, fracture, damage, toughening mechanisms, bridging, cracks, microcracks, cavitation, debonding

18.Basista M., Micromechanical and Lattice Modeling of Brittle Damage (Praca habilitacyjna), Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.3, pp.1-237, 2001
19.Basista M., Równania konstytutywne i ocena nośności granicznej ośrodków ze wstępną anizotropią struktury (Praca doktorska), Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.41, pp.1-96, 1985
20.Basista M., O kontynualnych modelach uszkodzenia materiałów, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.40, pp.1-53, 1984
21.Basista M., Dolna ocena nośności granicznej ośrodków plastycznie anizotropowych w płaskim stanie odkształcenia, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.2, pp.1-29, 1981

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
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

Abstract:
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.

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

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
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

Abstract:
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.

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

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
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

Abstract:
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.

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

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
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

Abstract:
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.

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

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
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

Abstract:
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.

Keywords:
Intermetallics, nickel-aluminides, turbine blades

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
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

Abstract:
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 ].

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

7.Poniżnik Z., Nowak Z., Basista M., Numerical modeling of fracture toughness of metal-ceramic interpenetrating phase composites with account of material microstructure, SolMech 2016, 40th Solid Mechanics Conference, 2016-08-29/09-02, Warszawa (PL), No.P198, pp.1-2, 2016
Poniżnik Z., Nowak Z., Basista M., Numerical modeling of fracture toughness of metal-ceramic interpenetrating phase composites with account of material microstructure, SolMech 2016, 40th Solid Mechanics Conference, 2016-08-29/09-02, Warszawa (PL), No.P198, pp.1-2, 2016

Abstract:
The motivation for research on interpenetrating phase composites and possible applications of these novel materials were given in [1]. A rationale behind designing an IPC is to achieve a highly durable material that would combine the most desirable properties of the constituent phases: the high hardness and wear resistance of ceramic and improved fracture toughness and thermal conductivity due to the metal content. The interpenetrating metal-ceramic composites may have remarkable applicability in different sectors of industry, e.g. automotive and aerospace. They should, thus, be carefully investigated in terms of processing routes, material properties and modeling of material response to service conditions.
A 3D FEM model in ABAQUS of the fracture parameters and crack growth in bi-continuous metal-ceramic composites with interpenetrating microstructure (IPC) is proposed. The crack is modeled using the extended finite element method (XFEM) [4]. The J-integral and fracture toughness KIc are determined for a real IPC microstructure obtained from micro-CT images. The fracture parameters (i.e. fracture toughness KIc, J integral, crack opening displacement) are key mechanical characteristics of IPC composites because of the brittleness of the ceramic phase. The main effects occurring in metal-ceramic IPC during fracture are described (cf. [2], [3]).

Keywords:
Ceramic-metal composites, interpenetrating microstructure, fracture toughness, crack growth, numerical modeling, XFEM

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
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

Abstract:
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.

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

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
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

10.Poniżnik Z., Nowak Z., Basista M., Numerical modeling of crack growth in interpenetrating metal-ceramic composites, ICDM2, 2nd International Conference on Damage Mechanics, 2015-07-08/07-11, Troyes (FR), pp.41, 2015
Poniżnik Z., Nowak Z., Basista M., Numerical modeling of crack growth in interpenetrating metal-ceramic composites, ICDM2, 2nd International Conference on Damage Mechanics, 2015-07-08/07-11, Troyes (FR), pp.41, 2015

Abstract:
A 3D FEM model for crack growth in bi‐continuous metal‐ceramic composites with interpenetrating microstructure (IPC) is proposed. The results for the load‐displacements relationship in a plastically deformable reinforcing fibre computed by means of different material models will be shown. The J‐integral and fracture toughness will be determined for a simplified IPC microstructure with reinforcing ligaments modeled as axisymmetric fibres, and for real IPC microstructure obtained from micro‐CT images

Keywords:
interpenetrating phase composites, bi‐continuous composites, metal‐ceramic composites, crack bridging, crack growth, fracture toughness, finite element method

11.Poniżnik Z., Basista M., Nowak Z., Modeling of effective elastic constants and fracture toughness in metal-ceramic composites with interpenetrating microstructure, ICF13, 13th International Conference on Fracture, 2013-06-16/06-21, Beijing (CN), No.S12-009, pp.81, 2013
Poniżnik Z., Basista M., Nowak Z., Modeling of effective elastic constants and fracture toughness in metal-ceramic composites with interpenetrating microstructure, ICF13, 13th International Conference on Fracture, 2013-06-16/06-21, Beijing (CN), No.S12-009, pp.81, 2013

Abstract:
The paper is focused on modeling of the overall elastic properties and crack toughening mechanism by bridging in metal-ceramic interpenetrating phase composites (IPC). The Tuchinskii-Feng analytical model (Feng 2004) especially devised for IPC microstructures is further developed. Numerical FEM models of the effective elastic constants are implemented for the simplified 3-D cross microstructure and real microstructures based on micro-CT scans. The energy release rate increase due to crack bridging (Mataga 1989) is modeled numerically. The stress-displacement relationships in the reinforcing fibers undergoing large strains and delamination from the matrix materials are obtained and then applied as material models for the bridging reinforcements in compact-tension test specimen of the fracture toughness determination. The J integral for this specimen is calculated by FEM (Abaqus) with reinforcing ligaments modeled as truss and cohesive elements. The growth of a bridged crack is also modeled numerically.

Keywords:
Effective elastic constants, Fracture toughness, Crack toughening, Crack bridging, Metal-ceramic composites, FEM

12.Poniżnik Z., Basista M., Modelling of overall material properties and crack reinforcement by bridging fibres in metal-ceramic composites with interpenetrating phase microstructure, 1st International Conference on Damage Mechanics, 2012-06-25/06-27, Belgrade (XS), pp.273-276, 2012
Poniżnik Z., Basista M., Modelling of overall material properties and crack reinforcement by bridging fibres in metal-ceramic composites with interpenetrating phase microstructure, 1st International Conference on Damage Mechanics, 2012-06-25/06-27, Belgrade (XS), pp.273-276, 2012

Abstract:
The objective of this paper is the analytical and numerical modelling of the overall elastic properties and the crack bridging toughening mechanism in metal-ceramic composites with interpenetrating phase microstructure (IPC). The specific microstructure of the IPC makes the effective media/field models based on Eshelby's solution inapplicable to the estimation of the effective elastic properties of the IPC. The effective material constants were calculated analytically extending the Tuchinskii-Feng models devised for the IPC microstructure. Numerical FEM models were developed for two types of IPC microstructure: simplified 3-D cross structure and real microstructure obtained with computer micro-tomography scans. The micro-CT scans were transformed into FEM meshes using the Simpleware ScanIP/FE commercial software. The crack bridging mechanism was investigated assuming the metal ligament undergoing large plastic deformations (necking) and delamination from the surrounding elastic material (ceramic matrix). As a first step towards the numerical determination of J integral from the simulation of the CT (compact tension) test. the s-u relationship in the metal fiber was determined numerically and applied to compute the stress and displacement fields in the CT specimen. The numerical solution agrees well with the analytical one obtained by Mataga et al. [4].

Keywords:
Interpenetrating phase composites, metal-ceramic composites, overall material properties, crack bridging, finite element method, micromechanics, microstructure

13.Węglewski W., Basista M., Modelling of thermal stresses and damage in Cu/Al2O3 interpenetrating phase 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
Węglewski W., Basista M., Modelling of thermal stresses and damage in Cu/Al2O3 interpenetrating phase 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

Abstract:
There is an urgent technological need for elements performing in demanding service regimes (especially in automotive and aerospace applications) to be made of new materials having superior properties such as higher strength and Young's modulus, enhanced temperature resistance and thermal shock resistance, improved corrosion and wear resistance, as well as reduced specific weight and better recycling potential. The Interpenetrating Phase Composites (IPC) could be a good answer to these industrial and commercial needs. But still a lot of problems appear during the processing of this type of metal-ceramic composites. One severe problem is the large thermal stresses generated during the cooling after the infiltration which can lead to initiation and propagation of microcracks and, thus to harmful decrease of the elastic properties of material.

In this paper, a FEM model is developed for the calculation of thermal residual stresses inside the IPC composites. The FE mesh is generated by the commercial software (ScanFE and ScanIP) based on the real material microstructure obtained from computer microtomography. The stress cracking condition is applied and the influence of the thermal stress induced microcracks on the elastic material parameters is shown. The comparison of the Young modulus furnished by the FEM model with the experimental data is presented.

Keywords:
interpenetrating phase composites, thermal stress, FEM, microcracking

14.Węglewski W., Basista M., Pietrzak K., Thermal stress and microcracking in the processing of the interpenetrating phase composites, SolMech 2010, 37th Solid Mechanics Conference, 2010-09-06/09-10, Warszawa (PL), pp.118-119, 2010
Węglewski W., Basista M., Pietrzak K., Thermal stress and microcracking in the processing of the interpenetrating phase composites, SolMech 2010, 37th Solid Mechanics Conference, 2010-09-06/09-10, Warszawa (PL), pp.118-119, 2010

Abstract:
The interpenetrating phase composites (IPC) are strongly different in their morphology, properties and processing than typical metal matrix or ceramic matrix composites. The basic morphological difference in comparison with particulate reinforcement composites is that the two components of IPC form continuous, interpenetrating 3D network. The IPC are more homogeneous, have better mechanical and thermal properties (abrasibility and fracture toughness, thermal conductivity and mechanical stability) than the matrix composites. The processing of IPC is typically done by a pressure or pressureless infiltration of ceramic porous matrix with a molten metal. The infiltration is a high temperature process (e.g. for Cu/Al2O3 IPC the infiltration temperature is above 1200OC and for Al/Al2O3 about 700 OC) which is usually associated with the generation of thermal stresses because of largely different coefficients of thermal expansion of the IPC components. The aim of this work was twofold: (i) to build a numerical model of thermal stress generated during the processing of the interpenetrating phase composites, and (ii) to build a numerical model of the initiation and growth of microcracks induced by the thermal stresses during the processing of the IPC. The results yielded by the models were compared with the experimental data. The models can be used to improve the processing of IPC by providing feedback as to how to reduce thermal residual stresses and how to minimize a risk of the microcracking during the production of the IPC.

Keywords:
interpenetrating phase composites, residual stress, microcracking, damage modelling