Effects of CeO₂ Content on Friction and Wear Properties of SiCp/Al-Si Composite Prepared by Powder Metallurgy

SiCp/Al-Si composites with different CeO₂ contents were prepared by a powder metallurgy method. The effect of CeO₂ content on mechanical properties, friction and wear properties of the composites was studied. The results show that with the increase in CeO₂ content from 0 to 1.8 wt%, the density, hardness, friction coefficient of the composites first increases and then decreases, the coefficient of thermal expansion (CTE) and wear rate of the composites first decreases and then increases. When the content of CeO₂ was 0.6 wt%, the density and hardness of the composite reached the maximum value of 98.54% and 113.7 HBW, respectively, the CTE of the composite reached the minimum value of 11.1 × 10^-6 K^-1, the friction coefficient and wear rate of the composite reached the maximum value of 0.32 and the minimum value of 1.02 mg/m, respectively. CeO₂ has little effect on the wear mechanism of composites, and the wear mechanism of composites with different CeO₂ content is mainly abrasive wear under the load of 550 N. Compared with the content of CeO₂, load has a great influence on the wear properties of the composites. The wear mechanism of the composites is mainly oxidation wear and abrasive wear under low load. With the increase in load, the wear degree of abrasive particles is aggravated, and adhesive wear occurs under higher load.