Influence of TiC particulate reinforcement on the corrosion behaviour of Al 6061 metal matrix composites

Aluminum matrix composites (AMCs), reinforced with ceramic particulates, have significant applications in the field of aerospace, marine, automobiles, sports and recreation. Al-TiC particulate composite has better potential for high-temperature applications. The corrosion behaviour of Al 6061-TiC particulate composites prepared by stir casting route, has been explored in chloride medium using electroanalytical techniques such as Tafel, Cyclic polarization and Impedance measurements (EIS). SEM and EDX analysis of the microstructures obtained in both matrix alloy and reinforced composites were performed in order to know the effect of titanium carbide on the corrosion resistance of composites. The polarization studies reveal an increase in the corrosion resistance in composites compared to the matrix alloy. The observed increase in corrosion resistance of TiC particulate reinforced composites is attributed to excellent bond integrity of TiC particulates with aluminium and possible electrochemical decoupling between TiC particles and Al 6061 matrix alloy. The EIS study reveals that the polarisation resistance (Rp) increase with increase in TiC content in composites and the corrosion process is mainly charge transfer controlled. Titanium carbide is proved to be a potential reinforcement for improved corrosion resistance in Al MMCs. Copyright © 2015 VBRI Press.