Microstructure and fretting wear of laser cladding self-lubricating anti-wear composite coatings on TA2 alloy after aging treatment

Abstract

Fretting wear, as an unique form of material degradation, was researched relatively scarce compared with sliding wear in recent study, especially on influence of aging treatment on the fretting wear property of laser cladded composite coatings. In order to investigate the effect of aging treatment on microstructure and fretting wear of laser cladding self-lubricating anti-wear composite coatings on TA2 alloy, the composite coatings were prepared on TA2 alloy by laser cladding with precursor mixed WS2-TiC-Ti (mole ratio of 1:3:6) powders, and the fabricated coatings were heated at 300 °C, 500 °C and 700 °C in vacuum for 1 h, respectively. The microstructure, micro-hardness, fretting wear properties of as-laser cladded and heat-treated composite coatings were studied systematically. The results show that the composite coatings mainly contain three types of phases: the carbides (Ti,W)C1−x and TiC, α-Ti, sulfides TiS and Ti2SC. The micro-hardness of composite coatings after aging treatment is higher than the coating without aging treatment. The main wear mechanisms of composite coatings after aging treatment at 700 °C are abrasive wear and adhesive wear, and the composite coating exhibits good fretting wear property.