The role of grain boundary sliding on the creep deformation behavior of discontinuously reinforced composites

摘要

In this study,the role of grain boundary sliding behavior and reinforcement morphology on the creep deformation characteristics of discontinuously reinforced composites is investigated.The results obtained for the composites are compared with the results obatined for a polycrystalline matrix material having identical grian size and morphology.The results indicate that,with sliding grain boundaries,the stress enhancement factor for the composites is much higher than the one observed for the matrix material and its value increases with increasing reinforcement aspect ratio.In the composites,the contribution of the grain boundary sliding to overall steady state creep rates occurs in a larger stress range in comparison to the matrix material,and experimentally observed higher creep exponent values or stress dependent creep exponent values for the composites could not be explained solely by the mechanism of grain boundary sliding.