Wear properties of magnesium matrix composites reinforced with SiO2 particles

Purpose - The purpose of this paper is to improve the wear resistance and tribological properties of magnesium and its alloys in order to apply them to the friction components. Design/methodology/approach - Wear test, microhardness measurements, X-ray diffraction (XRD), optical and electron microscopy examinations were applied. Findings - The ceramic SiO2, which has different particle-sized reinforced pure Mg-SiO2 composites, is produced by powder metallurgy using high ball milling, pressing and sintering. Mg2Si and MgO intermetallic phases produced by powder metallurgy in the Mg-SiO2 composite are dispersed as homogeneous into the Mg matrix. Mg-SiO2 composites exhibited a lower wear rate than the unreinforced pure magnesium specimens. Despite the pure Mg, the wear resistance of the composite is 61 per cent and the wear volume decrease with reducing SiO2 particle size. The hardness of the composite is increased in a ratio of 70 per cent with the distribution of the Mg2Si and MgO phases into the Mg matrix. Practical implications - In this paper, pure Mg powder with purity of 99.9 per cent and SiO2 powders with a mean particle size of 500, 250, 125, 75 and 10 gm are mixed by mechanical alloying. The wear behaviour of Mg-SiO2 composite, with the different particle-sized composites dispersed with Mg2Si and MgO intermetallic phases under dry friction condition is studied. The microstructural and mechanical properties of composite material samples are determined by differential scanning calorimeter, XRD, microhardness, optical and scanning electron microscopy tests. Originality/value - SiO2 particles distributed in the matrix are effective to improve hardness and wear resistance when contacting counter materials. In the present study, the magnesium powders with different particle size SiO2 powders are mechanically alloyed with a Turbola Spex 80000 mixer.