Experimental and numerical investigation on strengthening mechanisms of nanostructured Al-SiC composites

Abstract

In this paper, an accumulative roll bonding (ARB) process is exploited to produce high-strength, fine dispersed and uniform distribution of Al-5vol.%SiC nanocomposite. The microstructure illustrates and validates a good distribution of SiC reinforced in the Al 1050 matrix. It is observed that, an increasing of ARB passes tends to decrease and refine the size of SiC particle to nanoscale. It is concluded from tensile test that, as number of passes increases, strengths of Al ARBed and composite samples are improved. However, their ductility decreases at initial ARB pass and then increased. The Al-SiC tensile strength of nanocomposite sample is greater 5 times than the annealed Al 1050 used as the original raw material. The strengthening of composite sample occurs due to grain refinement, uniformity, reinforcing role of particles, strain work hardening, and bonding quality. From hardness test, after the initial pass, the hardness improved quickly, then dwindled and finally saturated by further rolling. Experimental data is exploited to derive governing equations describe the effect of the number of ARB passes on the tensile strength and elongation of manufactured nanocomposite samples. It is found that, the tensile strength and elongation can be described as an exponential function that depends on the number of passes. Numerical results from these equation are more consistent with experimental investigation.