Thermal effects on mild wear transition in dry sliding of aluminium 7075-short glass fibre composites

Abstract

The unlubricated sliding high temperature wear behaviour of A17075 alloy composites reinforced with short E-glass fibre was evaluated. A17075-glass composites were prepared by the liquid metallurgical technique with 2, 4 and 6 per cent by weight. A high temperature sliding wear apparatus, with temperature range 30-200°C, was used to evaluate the wear rate. Results indicated that addition of short glass fibre to A17075 alloy not only delays the transition wear (transition between mild and severe wear) but also reduces the wear rate. However, in both unreinforced alloy and reinforced composites, the wear rates increased with increases in the load, operating temperature and sliding speed. Increase in the applied load and operating temperature increased the wear severity by changing the wear mechanism from adhesion wear to debris cracking induced delamination wear. The observations have been explained using scanning electron microscopy, X-ray diffraction and energy-dispersive spectroscopy analysis of the worn surfaces and the debris.