Corrosion and wear characteristics of Al-Zn based composites reinforced with martensitic stainless steel and silicon carbide particulates

The corrosion and wear characteristics of stir-casting processed Al-Zn based composites reinforced with (6, 8, and 10 wt%) martensitic stainless steel (SS), was studied. Potentiodynamic polarization based electrochemical method was used for the corrosion studies in 0.3 M H₂SO₄ solution; while dry sliding wear test conducted using a tribometer, was adopted for the wear assessment. The results indicate that the thermodynamic feasibility and kinetic susceptibility for corrosion in the acidic solution, reduced with increase in the wt% of martensitic stainless steel in the Al-Zn based composites. Also, the corrosion resistance of the Al-Zn based composite containing 10 wt% martensitic stainless steel was higher than that of the composite grade containing 10 wt% SiC. The improved corrosion resistance was linked to the chromium and nickel contents in the stainless steel, which aid the formation of stable passive films on the composite surface that mitigate corrosion attack substantially. Similarly, the wear resistance of the Al-Zn based composite improved with increase in wt.% of the martensitic stainless steel – with the Al-Zn composite reinforced with 10 wt% SS having the best wear resistance value of 0.09136 mm³/n/mm and the least worn track section value of 232373.8 µm³. The improved wear resistance was attributed to the presence of more martensitic stainless steel particles in the composites; however the wear mechanism was essentially by abrasion regardless of the composite composition.