Shear punch test in Al/Alumina composite strips produced by powder metallurgy and accumulative roll bonding

Al-0.2, 0.4, and 0.8wt% alumina composites were manufactured via powder metallurgy and hot rolling techniques successfully followed by the accumulative roll bonding (ARB) process. Microstructural characterization of the composite strips thus fabricated was carried out using optical and scanning electron microscopy. The shear punch test (SPT) and Brinell hardness measurements were used to investigate the mechanical properties of the ARB-ed samples, which revealed that alumina powder particles became more uniformly distributed with increasing number of ARB cycles. Regarding porosity, no pores could be detected among the Al and alumina particles after the fifth ARB cycle. The results also indicated that shear elongation percentage of the specimens decreased before it gradually increased with increasing number of ARB cycles while their shear strength and hardness improved. Another finding of the present study was that the shear failure surfaces of the hot rolled strips exhibited a ductile fracture with a dimple structure while those processed by the ARB technique demonstrated shear flattened surfaces.