EFFECT OF TIO2 PARTICLES ON THE MECHANICAL AND MICROSTRUCTURAL EVOLUTION OF HYBRID ALUMINUM-BASED COMPOSITES FABRICATED BY WARB

Abstract

In this study, the effect of powder particle contents on the mechanical properties of aluminum-based hybrid composites produced by warm accumulative roll bonding (WARB) process was investigated. Three hybrid composite groups with fully annealed AA1060 strips, 1[Formula: see text]wt.% of MnO2 and 0, 7.5 and 15[Formula: see text]wt.% of TiO2 were first roll-bonded and then the ARB process continued up to eight rolling cycles. In the WARB process, the samples were preheated at 300∘C for 5[Formula: see text]min before each rolling cycle. It was realized that increasing the number of ARB cycles with 0 and 7.5[Formula: see text]wt.% of TiO2 particles improved the uniformity of TiO2 particles distribution in the aluminum matrix. Also, in samples with high contents of TiO2 particles (15%), TiO2 clusters converted into small clusters with a better distribution through the aluminum matrix. Also, by increasing the number of cycles and TiO2 wt.% up to 15%, the tensile strength, elongation, tensile toughness and average Vickers microhardness of hybrid composites were increased first and decreased then. Moreover, the effects of ARB cycles and TiO2[Formula: see text]wt.% on the fracture surface of hybrid composites have been studied by scanning electron microscopy (SEM). It was found that all the samples fabricated with one and two ARB cycles exhibited a typical ductile fracture containing deep dimples, whereas by increasing the TiO2[Formula: see text]wt.% and ARB cycles, a combination of ductile and shear ductile fracture have been detected in the fracture behavior.