Investigation of mechanical properties of nanostructured Al-SiC composite manufactured by accumulative roll bonding

Abstract

To manufacture high-strength, fine dispersed and uniform distribution of Al-5 vol.% SiC composite, accumulative roll bonding process is proposed and applied through this study. The microstructure illustrates and validates a good distribution of SiC reinforced in the Al 1050 matrix. It is found that after eight pass, the mean grain size of the composite sample is 188 nm. It can be concluded from tensile test that by increasing the number of passes the strengths of both Al ARBed and composite samples increase; however, their ductility decreases at the initial accumulative roll bonding pass and then increases. The tensile strength of Al-SiC composite sample is greater than the annealed Al 1050 used as the original raw material by five times. The strengthening of the proposed composite sample occurs due to grain refinement, uniformity, reinforcing role of particles, strain hardening, bonding quality and size of particles. From the hardness test, it is concluded that, after the initial pass, hardness increased quickly, then dwindled and finally saturated by further rolling. Observations discovered that the failure mode in the composite occurs due to the shear fracture. From the experimental investigation, governing equations are derived to describe the effect of the number of accumulative roll bonding passes on the tensile strength and elongation of manufactured metal matrix composite materials. It is found that the tensile strength and elongation can be described as an exponential function of the number of passes. Numerical results from these equations are more consistent with the experimental investigation.