Tribological and corrosion behavior of (100-x)(Fe70Ni30)-(x)ZrO2 composites synthesized by powder metallurgy

The aim of the present work is focused on the effect of ZrO2 addition on the tribological and electrochemical behavior of (Fe,Ni) matrix based composites. (100-x)(Fe70Ni30)-(x)ZrO2 composites were prepared using powder metallurgy route, where x is 2.5, 5, 10 and 15 wt%. The formation of taenite γ-(Fe,Ni) and kamacite α-(Fe,Ni) phases in the matrix was evident from x-ray diffraction (XRD). ZrO2 particles have not participated in any intermediate phase formation and found to be dispersed in matrix as a unreacted phase. Corrosion test of prepared composites was conducted in 3.5% NaCl aqueous solution (simulated sea water) at room temperature. The pin on disc tribological tests has shown a strong impact of reinforcing hard ZrO2 particles in improving the wear resistance whereas the presence of both taenite and ZrO2 phases has contributed in improving the corrosion resistance. Increasing the fraction of ZrO2 reinforcement particles up to 10 wt% improves both the wear resistance and corrosion resistance. Beyond this limit, property degradation was evident. It is due to the high contact of ceramic to ceramic particles and weak metal/reinforcement interface at higher reinforcement content, resulting in brittle behavior. Electrochemical impedance spectroscopy (EIS) studies indicate the adsorption/diffusion phenomenon at the interfaces which is responsible for localized corrosion. Microstructural and surface roughness test before and after the tests were performed using scanning electron microscope (SEM) and profilometer studies.