Dry sliding wear behavior of Saffil fiber-reinforced Mg-10Gd-3Y-0.5Zr magnesium alloy-based composites

Dry sliding wear behavior of the creep-resistant magnesium alloy Mg-10Gd-3Y-0.5Zr and its composites have been investigated in this study. Magnesium matrix composites are prepared by squeezing casting infiltration of Mg alloy into Saffil preforms. Wear tests are conducted using ball-on-flat sliding wear set up under a sliding velocity range of 1-15 cm/s and at an applied load range of 1-8 N for a constant sliding distance of 150 m. According to results, mechanical and wear-resistance properties of magnesium alloy improved by introducing Saffil fibers, and the alumina binder composite has a higher strength and lower wear rate than silica binder composite. The wear rates of the matrix alloy, composites and their counter-face balls increase with increasing applied load. The increment of sliding velocities decreases the wear rate of the matrix alloy under the tested sliding velocities. A critical threshold of sliding velocity for the wear rate of both composites and their counter-faces is about 9 cm/s. Abrasion and plastic deformation are considered to be the dominant mechanism for the matrix alloy in tested conditions, and for both composites under low sliding velocity (<10 cm/s) and at low applied loads (1-5 N). Delamination is the wear mechanism of the silica binder composites at a high applied load (8 N). Adhesion and oxidation are the controlling wear mechanism of matrix alloy and composites under a sliding velocity of 15 cm/s.