High-temperature tribology of selective laser melted titanium alloys: Role of adhesive wear

Abstract Titanium alloys are emerging materials used in many engineering applications, especially in the turbine blades of aerospace due to their strength-to-weight ratio, corrosion resistance, and high specific strength. These are currently 3D printed using selective laser melting (SLM) to reduce component weight for aerospace applications. The hard external particles from the atmosphere repeatedly hit the blades in rotary nature. Due to significant sliding action between articulating surfaces, these alloys need good wear resistance. With this motivation, rotary wear tests at high vacuum high temperatures (HVHT) were conducted on the as-built and heat-treated titanium alloy (Ti6Al4V) fabricated by 3D printing of SLM process. The experiments with constant parameters of 100 rpm, 1000 cycles, 10 min, and varied temperatures showed that as-built and heat-treated samples against the alumina ball presented lower COF values at elevated-temperatures compared to room-temperature (RT). In addition, adhesion was the main wear mechanism at elevated-temperatures (400 °C and 850 °C). On the worn-out surfaces of the heat-treated samples, it is noticed that ploughing strips, ploughing ridges and shallow grooves were significantly noticed. Although low CoF values obtained at elevated-temperature on tested samples, higher wear volume was seen in these samples due to continuous removal of soft material.