Study On The Properties Of SiC Particle Reinforced Magnesium Matrix Composites Fabricated By Stir Casting Method

Magnesium alloy is a kind of structural material with low density, and it has higher specific strength. SiC particles have the advantages of high strength, high modulus, good thermal conductivity, and good wettability with magnesium alloy melt. As the reinforced magnesium matrix composites, SiC particles have excellent performance. Especially comparing to the matrix alloy, the wear resistance has been significantly improved.In this paper, AZ91 D is selected as matrix alloy, the particle size. SiC particle whose average size is 50?m is reinforcing phase. 15vol-%SiCp/AZ91 mixing furnace was made by mechanical equipment, whose interface combination, mixing temperature, mixing time and other parameters is analized by optical microscopy(OM), scanning electron microscopy(SEM) and Energy Dispersive Spectroscopy(EDS) to see it's effect on Particle uniformity. Subsequently, high temperature compression experiments were carried out at 300?, 400? and 500?to study the effect of different temperatures on the uniformity of the composite particles under the same pressure. Finally, the friction and wear experiments were carried out on AZ91 D alloy and composite materials with different temperature and high temperature. The friction and wear curves were drawn and the wear mechanism was analyzed.The research results show that: when the mixing time is 3min, a half solid stirring whose speed is 300r/min in the temperature of 585?will make the macro distribution of SiC particles very uneven and gather. When the stirring time is 13 min, the macro distribution of the SiC particles is not uniform and large space and agglomeration appears; when the stirring time is 23 min, SiC particles macro distribution is uniform; when the stirring time is 33 min, the macro distribution of the SiC particles are well distributed, and no obvious changes happen.In the high temperature compression test, under the same pressure appropriate, uneven distribution of composite micro particles is eliminated by high temperature change. Combined with composite micro topography analysis of and 500?, three compression parameters and to determine the 400? is the best temperature.Average friction coefficient of compression temperature in 500? is the largest, average friction coefficient of compression temperature in 300? is smaller than 500?, and the smallest in 400?.Compared with AZ91 D magnesium alloy matrix, the wear resistance of the composite increases by 20% and the average friction coefficient of the composites increased by compared with that of the alloy matrix, and the average friction coefficient decreases by 15%.Analysis of composite wear morphology, the combination of SiC particle and matrix alloy is better. In the wearing process of the composite, there are adhesive wear and abrasive wear mechanism that appears in the later period of wear.