Evaluation of microstructure and mechanical properties of Al/Al2O3/SiC hybrid composite fabricated by accumulative roll bonding process

• Al/Al2O3/SiC hybrid composite was fabricated by anodizing and ARB processes.
• With no. of ARB cycles, the uniformity of particles in the Al matrix improved.
• With no. of ARB cycles, the bonding quality between particles and matrix improved.
• The UTS of Al/1.6 vol.% Al2O3/1 vol.% SiC was 3.1 times higher than annealed Al.
• Increasing the amount of the SiC up to 2 vol.% in matrix decreased UTS and El%.

In this investigation, a new kind of metal matrix composites with a matrix of pure aluminum and hybrid reinforcement of Al2O3 and SiC particles was fabricated for the first time by anodizing followed by eight cycles accumulative roll bonding (ARB). The resulting microstructures and the corresponding mechanical properties of composites within different stages of ARB process were studied. It was found that with increasing the ARB cycles, alumina layers were fractured, resulting in homogenous distribution of Al2O3 particles in the aluminum matrix. Also, the distribution of SiC particles was improved and the porosity between particles and the matrix was decreased. It was observed that the tensile strength of composites improved by increasing the ARB passes, i.e. the tensile strength of the Al/1.6 vol.% Al2O3/1 vol.% SiC composite was measured to be about 3.1 times higher than as-received material. In addition, tensile strength of composites decreased by increasing volume fraction of SiC particles to more than 1 vol.%. Scanning electron microscopy (SEM) observation of fractured surfaces showed that the failure mechanism of broken hybrid composite was shear ductile rupture.