Effect of reinforcement and sintering on dry sliding wear and hardness of titanium – (AlSi)0.5CoFeNi based composite

Abstract

Abstract Owing to its weight-to-strength ratio, titanium is a widely used material, especially in gas turbine engines. It possesses a high melting point and corrosion resistance, however, exhibits poor wear resistance. An improvement in its tribological properties can be accomplished by the addition of a suitable reinforcement in metal matrix composite (MMC). In this research, titanium MMCs were fabricated through mechanical alloying (MA) followed by vacuum arc melting of 95% titanium reinforced with 5% of (AlSi)0.5CoFeNi high entropy alloy (HEA). Compaction was later done at 1000 MPa, while specimens were heat-treated at sintering temperatures of 900 °C and 1000 °C, with varying sintering times of 1 h and 2 h at 10–4 millibar vacuum. Microhardness and sliding wear rate of reinforced HEA specimens exuded improvement when compared to the Ti 900 °C 2 h specimen. Owing to the reinforcement, a reduction in wear rate and more than 5% improvement in microhardness had been observed, at higher sintering temperatures. The improvement was attributed to the synergistic effect of sintering time and temperature during the density and wettability analysis which was supported by the morphological analysis.