Finite element modeling of particle cracking in metal matrix composites.

摘要

Finite element analysis was used to simulate reinforcement particle cracking in Al/SiCSimulations of the thermal misfit stress that develops during high temperature processing of the composite show that these stresses severely affect the subsequent mechanical behavior of the composite. Thermal misfit stress was shown to reduce average matrix strain and decrease elongation of the composite. Higher reinforcement volume fractions had higher levels of matrix stress when thermal residual stresses were addressed with corresponding decreases in matrix strain.FEA simulations of reinforcement particle cracking showed that the thermal misfit stresses lessen the impact of reinforcement particle cracking on the surrounding matrix.The distribution of stress and strain in the matrix during tensile loading was examined for several reinforcement volume fractions of cylindrical and spherical particles. The average matrix strain was found to increase linearly with applied strain for both cylindrical and spherical reinforcement particles.FEA of reinforcement particle cracking in an Al-9 vol.% SiCSimulations of the effect of matrix strength on particle cracking showed that matrices without thermal residual stress had similar stress distributions after cracking of the reinforcement particle. Simulations without consideration of thermal misfit stress were severely affected by particle cracking but matrices of composites with thermal misfit stress showed very little change in matrix stress distribution. The thermal residual stress was found to sufficiently mask the stress resulting from particle cracking, thus making the effects of particle cracking more local. (Abstract shortened by UMI.)