Effect of thermal expansion on interface wear and electrical performance degradation of high speed sliding electrical contact

High-current and high speed sliding electrical contacts are subjected to intense transient heating. The temperature increases rapidly and the material expands accordingly, which alters contact stress and wear behavior. The interactions among electromagnetic, thermal, and mechanical effects and the resulting changes in electrical performance have not yet been fully understood. To address this issue, a wear model incorporating transient thermal expansion is developed and solved numerically. Deformation at the contact interface caused by temperature rise is considered, and its influence on stress distribution and wear evolution under high speed sliding is captured. An integrated experimental platform with coupled electromagnetic, thermal, and mechanical loading is established for the experimental validation of the proposed model. The predicted maximum wear depth of 1.9 mm agrees with the measured value of 2.0 mm, with a deviation of about 5%. The effective contact area is reduced by about 7.4%, accompanied by a decrease of about 7.5% in current transmission efficiency. A clear link between interface wear and electrical performance degradation is identified. Thermal expansion is shown to enhance local deformation and accelerate wear, thereby reducing electrical efficiency. The proposed framework provides guidance for interface design and reliability improvement in high current electrical systems.