Wear behaviour of titanium alloy GTM-900 under dry sliding

Dry sliding wear behaviour of titanium alloy GTM-900 was investigated using a pin-on-disc wear testing machine. The alloy was solution treated in the alpha+beta and beta phase fields separately and cooled in air to produce duplex microstructure of primary a and transformed beta and fully transformed beta in the respective heat treated conditions. The sliding wear rate of the alloy in both of above heat treated conditions was observed to increase with the applied load. However, at a constant load, the rate of wear decreased with an increase in the sliding speed, to a minimum and then increasing trend was observed. Examination of wear debris by stereomicroscope and SEM and analysis of the worn surface by SEM revealed formation and smearing of oxides as well as distortion and removal of the metallic material from the mating surface. Microploughing on the sliding surface of the alloy, and dislodging of the material were also quite evident. The rate of wear was found to be higher in the beta-treated than that in the alpha+beta treated condition.