Effect of magnesium on sliding wear performance of cast Al-8.3Fe-0.8V-0.9Si alloys

Abstract

The paper deals with the sliding wear behaviour of cast Al-Fe-V-Si alloys evaluated by 'pin on disc' tribometry. The alloys were castin cylindrical15 mm diameter metallic moulds from which 8 mmdiameter pins were machined. Volumetric wear loss and coefficient of friction were measured. Worn surfaces of the pins were examined by scanning electron microscopy. It was observed that by modifying the Al-Fe-V-Si alloys with Mg or Al-Mg master alloy the structure of Al₁₃Fe₄ precipitate changed from ten-armed star-like to hexagonal, rectangular, cuboidal, and other compact forms. The wear rate of the cast Al-Fe-V-Si alloys was much lower than that of eutectic Al-Si alloy. Modified Al-Fe-V-Si alloys exhibited lower wear rate and coefficient of friction than the unmodified Al-Fe-V-Si alloy. The wear rate decreased with increasing load for the modified Al-Fe-V-Si alloys. Both the wear rate and coefficient offriction were found to be load dependent. During wear extensive plastic deformation and work hardening occurred. The wear was shown to take place by delamination.