Effect of grain size on thermal residual stresses and damage in sintered chromium-alumina composites
Measurement and modeling
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.