Current–Carrying Wear Characteristics of Al-Cu Alloys with Different Al-5Ti-B Additions
摘要
Al-15Cu alloys with varying grain refiner Al-5Ti-B contents were prepared in a resistance melting furnace and then processed into disc specimens (Φ60 × 5 mm) for test. Wear tests with an electric current density of 0-3.2 A mm-2 were conducted on these alloys paired with stainless steel using a self-designed pin-disc type electric current–carrying wear test stand, and the microstructure, hardness, conductivity, tensile strength, wear properties, and mechanisms of the modified Al-15Cu alloy were investigated. The results showed that Al-5Ti-B significantly refined the α-Al grains and dispersed the eutectic structure in the alloy, resulting in substantial improvements in both mechanical properties and electric conductivity. As the Al-5Ti-B content increased, the variation range of the electric current–carrying specific wear rate decreased, with a maximum reduction of 22.7% in the specific wear rate observed with the addition of 1.5% Al-5Ti-B. Additionally, the average wear track depth and maximum grind marks depth were reduced by up to 44.8% and 39%, respectively. The surface temperature was notably affected by the electric current, with a steady-state temperature increase of up to 81.3%. Furthermore, the Al-5Ti-B content also influenced the steady-state temperature, which increased by up to 17.3% with increasing Al-5Ti-B content. In addition, the introduction of Al-5Ti-B delayed the delamination wear of the Al-15Cu alloy in the absence of current, which was diminished when a contact electric current was applied.