Effects of Interphase Regions of Particulate-Reinforced Metal Matrix Nanocomposites Using a Discrete Dislocation Plasticity Model

Abstract

Metal matrix nanocomposites (MMNCs) show significant promise for use as structural and/or functional materials. In recent years, discrete dislocation simulations have been used to perform a numerical analysis on MMNCs. Although the trend of increasing flow stress and degree of hardening with a larger particle volume fraction and decreasing particle size were captured by existing simulations, the effects of these parameters on the mechanical behavior of MMNCs shown in these analyses were not as substantial as those reported in experiments. Meanwhile, the presence of thermally induced dislocations and chemical reactions between the matrix and inclusions suggest that interphase regions should be accounted for in the simulation. By using a level set in the extended FEM (XFEM), interphase regions are introduced into the numerical model. The effects of elastic properties, thickness of the interphase regions, and resistance to dislocation motion within the interphase regions are examined in this study.