A study of mechanical properties and fractography of ZA-27/titanium-dioxide metal matrix composites

This paper reports an investigation of the mechanical properties and the fracture mechanism of ZA-27 alloy composites containing titanium-dioxide (TiO2) particles 30-50 mum in size and in contents ranging from 0-6 wt.% in steps of 2 wt.%. The composites were fabricated by the compocasting technique. The results of the study revealed improvements in mechanical properties such as Young's modulus, ultimate tensile strength, yield strength and hardness of the composites, but at the cost of ductility. The fracture behavior of the composites was influenced significantly by the presence of titanium dioxide particles. Crack propagation through the matrix and the reinforcing particles resulted in the final fracture. Scanning electron microscopy (SEM) analyses were carried out to furnish suitable explanations for the observed phenomena.