The effect of nickel-induced finite plasticity on the tribological behavior and wear resistance of Cu-Sn-Bi alloy

This article investigates the effect of nickel-induced finite plastic deformation at the friction interface of the CuSn10Bi3 bimetallic copper layer on its tribological properties. CuSn10Bi3 alloy bimetallic samples with different nickel contents were prepared by powder metallurgy, and the microstructure and Brinell hardness were observed. The tribological performances and wear behaviors under dry friction and oil-depleted lubrication conditions were evaluated and analyzed. The results show that the Ni in the copper-tin-based alloy reduces the surface porosity of the powder metallurgical samples. With the increase of Ni content from 0.5 wt% to 1.2 wt% and 2 wt%, the porosity decreased by 36%, 48.7% and 62.3%, respectively, and the hardness of the samples increased slightly. The grain size of the alloy decreases with the increased Ni content, which is attributed to the increase of twinning. Besides, the friction coefficient of Ni-containing samples was more stable and the wear under dry friction was significantly reduced, especially, the wear loss is reduced by 78.2% when the content of Ni is 2%. The wear mechanism changed from abrasive-dominated and oxidative wear to plastic deformation dominated and furrow wear. The limited plastic deformation of the friction interface caused by the addition of 2% nickel is a new strategy for solving the problem of brittle exfoliation of wear surfaces and improving the wear resistance of Bi-containing copper alloys.