Effect of interfacial bonding on uniaxial ratchetting of SiC_p/6061Al composites: Finite element analysis with 2-D and 3-D unit cells

摘要

The effect of interfacial bonding state between particulate and metal matrix on the ratchetting of SiC particulate reinforced 6061Al alloy composites (i.e., SiCp/6061Al composites) in uniaxial cyclic stressing at room temperature was discussed by numerical simulation using a finite element code ABAQUS. In simulation, axi-symmetrical two-dimensional (i.e., 2-D) mono-particle and three-dimensional (i.e., 3-D) multi-particle unit cells were employed, respectively. The ratchetting of un-reinforced matrix alloy was addressed by an elasto-plastic constitutive model with nonlinear kinematic hardening rale, and the particulates were assumed as elastic. Two kinds of interfacial layers were inserted into the unit cells between particulate and matrix, i.e., elastic and elasto-plastic interfacial layers previously employed by Kang et al. [G.Z. Kang, Q. Gao, Composites A 33 (2002) 657-667] in the numerical simulation for monotonic tensile behavior of short fiber reinforced metal matrix composites. Finally, the ratchetting of T6-treated SiC_p/6061Al composites was simulated by using 3-D multi-particle unit cell and suitable interfacial property parameters. It is shown that the simulated results are closer to the corresponding experiments than those obtained with assumption of perfect interface. Simultaneously, some microscopic deformation features in the composites and their evolution rales were also revealed by the numerical simulation. Some significant conclusions are obtained, which are useful to establish a constitutive model to describe the ratchetting of the composites.