Tribological properties of Al/PI composites sliding with Ti-6Al-4V alloy

Aluminium/polyimide (Al/PI) powders were prepared via in situ. Al/PI composites were fabricated by hot pressing technology at 723 K for 30 min under Ar. The microstructure, thermal stability and tribological properties of Al/PI composites were investigated. SEM images showed that Al particles were wrapped in the composite with no gap. According to the TG analysis, 15Al/PI composite showed excellent thermal stability up to 773 K. Meanwhile, 15Al/PI composites exhibited excellent tribological behaviour at high temperature, especially at 773 K. The friction coefficient of 15Al/PI composite at 773 K was about 0.28 which was lower than that of pure PI (about 0.41). The wear rate of 15Al/PI composite at 773 K was about 65 × 10−5 mm3 Nm−1. The tribological properties of Al/PI composites was improved at high temperature. In the process of sliding tests, Al particles were transferred to the Ti-6Al-4V alloy's surface and PI particles were pressed on the composite's surface. The transfer of Al can protect Ti-6Al-4V alloy from wear and reduce the friction coefficient during the sliding test.