Reduction in Coefficient of Thermal Expansion of Cu‐Based Self‐Lubricating Composites without Decreasing Wear Resistance by the Addition of Ni50Fe

Cu‐based self‐lubricating composites have excellent mechanical properties and enhanced friction characteristics, rendering them ideal for aerospace wear parts. However, the significant mismatch in coefficients of thermal expansion (CTE) between them and counterparts, typically steel, would limit their widespread application. To address this issue, Ni50Fe powders with a low CTE are incorporated into Cu15Ni8Sn‐MoS 2 composites via mixing and hot‐pressed sintering, resulting in Cu15Ni8Sn‐Ni50Fe‐MoS 2 composites. The addition of Ni50Fe significantly reduces the CTE of the composites. When added in moderation, Ni50Fe can enhance the mechanical properties and wear resistance, despite a slight degradation in lubricity. The variations in mechanical and friction properties of the composites are attributed to the reaction of Cu and Fe with MoS 2 and the change of matrix composition. The composite containing 40 vol% Ni50Fe (N40) has the best comprehensive performance. Compared to the Cu15Ni8Sn‐MoS 2 composite, the CTE of N40 is reduced by 13.7%, along with increases in hardness (5.2%), transverse rupture strength (19.1%), radial crushing strength (11.3%), and a reduction in wear rate (8.8%), although its friction coefficient increases by 15.4%.