Improved wear resistance and mechanism of titanium aluminum based alloys reinforced by solid lubricant materials

Abstract

Abrasion failure is a bottleneck problem that restricts the applications of titanium aluminum (TiAl) based alloys. This work has developed a facile method to endow TiAl alloys with superior wear resistance. TiAl composites reinforced by serpentine materials have been prepared by spark plasma sintering (SPS). Microstructural characterizations show that serpentine is well distributed in TiAl alloy matrix. Tribological behaviors in terms of a high-temperature friction and wear tester indicate that the reinforced particles play a positive role in decreasing wear rates and friction coefficients. Together with wear debris and high-temperature oxides, lubricant particles easily form a lubrication layer on frictional interfaces, which can help repair and compensate the worn-out pits and grooves thereby leading to the optimal wear resistance with the lowest friction coefficient of 0.41 and wear rate of 1.97 × 10−4 mm3/(Nm) at 400 °C–600 °C. This work sheds insights into evaluating the practicability of serpentine as a desirable solid lubricant and providing guidance for designing other serpentine-reinforced composites.