Fabrication of Al–2 vol% Al2O3/SiC hybrid composite via accumulative roll bonding (ARB): An investigation of the microstructure and mechanical properties

Abstract

An Al/Al2O3/SiC hybrid metal matrix composite was fabricated by accumulative roll bonding (ARB). A mixture of Al2O3 and SiC (2vol%) powders was poured between four Al layers during the first two ARB cycles. The process was continued up to eight cycles without adding the powders in subsequent cycles. For comparison, non-reinforced (monolithic) Al was also processed by ARB under the same conditions. At the initial stages, particle free zones as well as particle clusters were observed on the microstructure of the composite. After eight ARB cycles, a composite with a uniform distribution of particles was produced. At this stage, the tensile strength of the hybrid composite and the monolithic Al reaches to about 195MPa and 150MPa, respectively, about 5.3 and 4 times larger than that of annealed Al. The hardness of the composite and the monolithic Al was measured as 83 and 58 VHN, respectively. Fracture surface after tensile testing revealed dimples at some regions after eight ARB cycles.