Fabrication of Al/Al2O3/TiC hybrid composite by anodizing and accumulative roll bonding processes and investigation of its microstructure and mechanical properties

In the present study, Al/Al2O3/TiC hybrid composite was produced using anodized strips and accumulative roll bonding (ARB) process. Alumina layers with various thicknesses were firstly obtained by anodizing the aluminum strips at different times. The anodized strips were then used along with certain amount of TiC particles (1 vol%) as dispersed layer in order to fabricate Al/Al2O3/TiC hybrid composite. The resulting microstructures as well as the corresponding mechanical properties of the composites in different cycles of ARB process were studied. It was found that after one ARB cycle, departing and fracturing phenomena occurred in brittle alumina layer, followed by breaking down the alumina fragments to finer particles as the number of rolling cycles increased. In addition, by applying eight ARB cycles, the distribution of reinforcement particles (Al2O3, TiC) in aluminum matrix became highly uniform. It was shown that the mechanical properties of the hybrid composite such as tensile strength and elongation were enhanced as the number of ARB cycles increased. The results also showed that adding of up to 1.6 vol% alumina in aluminum matrix enhanced considerably the yield and tensile strength of hybrid composite, whereas increasing the amount of alumina to 2.1 vol% deteriorated the tensile properties. Finally, the fracture surfaces of the samples after the tensile tests showed that the fracture mode of composite was shear ductile rupture.