Wear Behavior of ZrO₂ Particle Reinforced (Fe,Ni) Matrix Composite

Abstract

Metal Matrix composites are an important class of engineering materials with enhanced hardness, wear, compressive strength, fracture toughness and corrosion resistance. Iron–Nickel alloys are well known for their superior wear, mechanical, corrosion and high temperature resistance characteristics. Present work is focused on the study of wear behavior of Fe-Ni alloy matrix based (Fe₇₀Ni₃₀)-ZrO₂ composites with varying ZrO₂ reinforcement content. ZrO₂ particles were found to be dispersed in matrix as un-reacted phase. (Fe,Ni) alloy specimens prepared using powder metallurgy route with different Fe/Ni ratio show the formation of α-(Fe,Ni) and γ-(Fe,Ni) phases, where γ-(Fe,Ni) phase increases with increasing Ni content. γ phase was found to be a soft and corrosion resistant phase as compared to α-(Fe,Ni). An increase in γ-(Fe,Ni) phase reduced the hardness and wear resistance of specimens but increased corrosion resistance in 3.5 wt% NaCl aqueous solution. In the present investigation a pin on disc wear testing machine was used for studying the tribological behavior of Fe₇₀Ni₃₀ (wt%) with ZrO₂ (0, 2.5, 5, 10 and 15 wt%) composite at three different loads i.e. 10, 20 and 30N. Presence of hard ZrO₂ particles reduced the plastic flow during sliding and attributed in improving the wear resistance of composite. Increasing the fraction of ZrO₂ reinforcing particles up to 10 wt% improves the wear resistance. Beyond this reinforcement limit, wear resistance decreased dramatically. It is due to the high contact of ceramic to ceramic particles and weak metal/ reinforcement interface at higher reinforcement content, resulting in brittleness in the composite.