Corrosion Behavior of AZ91/TiC/Al2O3 Hybrid Composites

Abstract

In the current research, the corrosion behaviors of AZ91 Mg-hybrid composites amalgamated with titanium carbide and alumina reinforcing particles have been investigated. AZ91 Mg-hybrid composites have been developed by using the bottom pouring vacuum-based stir casting process to attain the homogeneous distribution of reinforcing particles in the AZ91-Mg matrix. The corrosion behavior of AZ91-hybrid composites has been evaluated by using corrosion potential (OCP) and potential dynamic polarization scans, as well as friction coefficient, have been deduced to examine the wear behavior of hybrid composites in sodium chloride (3.5%) solution. However, before and after each corrosion and wear test of AZ91-hybrid composites samples, the metallographic structures have been examined by using a scanning microscopic setup. The corrosive results reveal that the corrosion rate of the AZ91-Mg matrix has been greater than AZ91/TiC/Al2O3 composites. The AZ91/TiC/Al2O3 composites result also confirms that the corrosion resistance increases with an increase in wt% of TiC and Alumina. The prime reason for to increase in the corrosion rate is due to the increase in the number of matrix/reinforcement interfaces. However, the friction coefficient and wear rate of AZ91 Mg-hybrid composites rose with the increase in TiC wt%. The type of wear mechanism of AZ91 Mg-hybrid composites has been demonstrated that initially abrasive wear has been observed but later it predominantly transforms to both (i.e., adhesive and abrasive wear) with an increase in TiC wt%.