Effect of aging treatment on interfacial microstructure and mechanical properties of Ni/babbitt alloy

In order to analyze the accelerated failure process of the Cu-based bearing, the influence of isothermal aging treatment on the microstructure and bonding strength of Babbitt alloy matrix, Sn/Cu joints, Sn/Ni joint, Ni/Babbitt static casting samples were analyzed. The results shown that the ratio of Cu₆Sn₅ phase in the Babbitt alloy matrix increases significantly after treatment at 176℃ and 500 h. The interfacial phase of Ni/Babbitt alloy (Ni₃Sn₄ phase) shown a thickening trend, its thickening speed is slower than the growth of Cu₆Sn₅ phase. The bonding strength of Sn/Cu, Ni/Babbitt alloy decreases with the increased of the aging time, and after 500 h the strength reduce to 22 MPa and 48 MPa, respectively. The reason for the former decreasing was the Cu₆Sn₅ brittle phase occur at the interface. The latter was lower, but it still met the technical requirements. The results shown that the addition of Ni layer on the surface of Cu matrix can effectively inhibit the formation of Cu₆Sn₅ phase and ensure the industrial applicability of Cu-based bearing after aging treatment.