Microstructure and wear resistance of laser melted TiCo/Ti₅Si₃ dual-phase intermetallic alloy

Dual-phase intermetallic wear resistant alloy with Ti₅Si₃ as the reinforcing phase and intermetallic TiCo as the toughening matrix was fabricated by the laser melting deposition process. The microstructure and composition of the TiCo/Ti₅Si₃ intermetallic alloy was characterized by OM, SEM, XRD and EDS. Metallic dry sliding wear property of the alloy was evaluated at room-temperature. The effect of toughening phase TiCo content on the microstructure, hardness and wear resistance of the TiCo/Ti₅Si₃ intermetallic alloy was investigated. The results indicate that the TiCo/Ti₅Si₃ intermetallic alloy has fine microstructure consisting of Ti₅Si₃ primary block-like phase uniformly distributed in the TiCo/Ti₅Si₃ eutectic structure. The alloy has excellent wear resistance under dry sliding wear test conditions. The volume fraction of the Ti₅Si₃ primary phase and the hardness of the TiCo/Ti₅Si₃ intermetallic alloy decrease with increasing of TiCo content, while the toughness and wear resistance of the alloy increase. The excellent wear resistance of the TiCo/Ti₅Si₃ intermetallic alloy was attributed to the high hardness of Ti₅Si₃ phase and the good toughness of TiCo phase.