Microstructure and tribological properties of Cu_ss-toughened Cr-Cu-Si metal silicide alloys

Wear resistant Cr-Cu-Si metal silicide alloys with different Cu contents were fabricated by the laser melting process. The Cr-Cu-Si alloys have a similar microstructure consisting of the Cr₅Si₃/CrSi dual-phase primary dendrites and the interdendritic Cu-based solid solution (Cu_ss). The Cu content has no effect on the phase constitutions of the alloys. The Cr₅Si₃/CrSi dendrite volume fraction and hardness of the Cr-Cu-Si alloys decrease with the increasing Cu content. Wear test results indicate that all the Cu_ss-toughened metal silicide alloys have excellent wear resistance and low coefficient of friction. Wear resistance increases and friction coefficient decreases with the decreasing Cu content.