Mechanical properties and fracture surface of Al-Al2O3 nano/micro-composites produced by accumulative roll bonding

Abstract

ABSTRACT The accumulative roll bonding (ARB) process has been utilised to produce layered materials and composites with high strength without intermediate annealing steps. This study focused on the size of reinforced particles (Al2O3) with an average size of 3 µm (m) and 80 nm (n) in aluminum matrix composites. Three different samples of monolithic Al, Al-1 vol.% (m)Al2O3, and Al-1 vol.% (n)Al2O3 particulate composites were produced by ARB. The SEM results revealed that the distribution of alumina particles in the fabricated composites was improved with increasing ARB cycles, while the Al-1 vol.% (m)Al2O3 composite presented the proper distribution of particles at higher cycles in contrast with the Al-1 vol.% (n)Al2O3 composite. The tensile strength of the produced composites was enhanced, and their ductility decreased with the increase in ARB cycles, while Al-1 vol.% (m)Al2O3 with a tensile strength of 253 MPa showed higher strength than Al-1 vol.% (n)Al2O3 with 229 MPa at the sixth cycle. By adding Al2O3 microparticles, the yield strength and tensile strength of the microcomposite sheet were increased to about 5 and 2.1 times, respectively, compared to the Al sheet.