Investigation of wear behaviors from room temperature to 500°C of in-situ synthesized ceramics reinforced composite coating on TA2 alloy by laser cladding

In order to enhance the wear property of TA2 alloy, ceramics reinforced composite coating was prepared on TA2 alloy by laser cladding with preplaced mixed WS2-TiC-Ti powders (mole ratio of 1:3:6). The micro-structure, phase compositions and micro-hardness of composite coating were analyzed in detail. The dry-sliding wear behaviors and corresponding wear mechanisms of TA2 alloy substrate and composite coating at different test temperatures (RT, 250 and 500°C) were also studied systematically. The results showed that α-Ti, TiS, Ti2SC, (Ti, W)C1−xand TiC were in-situ synthesized in laser processing. The micro-hardness of the coating was improved significantly due to the formation of carbide ceramics Ti2SC, (Ti, W)C1−xand TiC. The coating exhibited excellent wear property at 500°C, i.e. low friction coefficient (0.339) and wear rate (4.87×10−6mm3/Nm). The predominant wear mechanism of the composite coating was formation and peeling off of lubricating transfer films, with incidental effect of adhesive wear and oxidation wear.