Creep and Stress Relaxation Behavior of Metal Matrix Particulate Composites Induced by Interface Diffusion with Coupled Thermomechanical Strains

To investigate interfacial diffusion-induced creep and stress relaxation behavior of the particle-reinforced metal matrix composites, analytical solutions are obtained with coupled thermal and mechanical loads. The thermal expansion strains between the matrix and inclusion are considered as eigenstrains. Based on the Eshelby inclusion theory, the driving forces for interface diffusion and slip are obtained, respectively, and the relationship between them is elucidated. The effects of temperature-dependent elastic properties, thermal and mechanical loads on the creep rate and stress relaxation are estimated. Besides, the error caused by the scale effect is amended by fitting the finite element results with nonlinear least square method. The present results provide a straightforward guideline for designing high-quality metal matrix particulate composites.