ELASTOPLASTIC ANALYSIS OF THERMAL CYCLING - CERAMIC PARTICLES IN A METALLIC MATRIX

Elastoplastic deformation induced by the thermal cycling of a particle -reinforced metal is studied analytically and numerically. The represe ntative volume element considered for analysis is a spherical ceramic particle embedded within a hollow sphere of the metallic matrix. Close d-form solutions are derived for four characteristic temperatures whic h signify certain critical conditions for the onset and spread of plas ticity in the composite during thermal fluctuations. These conditions are then evaluated for a wide variety of commonly studied metal-cerami c composites. The effective coefficient of thermal expansion is derive d and is shown to be in agreement with finite element results obtained for an Al-SiC composite. Numerical simulations addressing plastic str ain accumulation and interfacial decohesion during thermal cycling are also discussed with tile objective of providing some guidelines for t he estimation of thermal fatigue life.