比较研究SiC和MoS2对铝基复合材料磨损行为影响

摘要

为了提高纯铝对钢的干滑动摩擦耐磨性,通过压制烧结混合粉末的方法制备不同SiC、MoS2和SiC/MoS2颗粒含量的铝基复合材料.显微结构分析表明,该合金结构致密,这与密度和硬度测试结果相吻合.在恒定载荷和滑动速度下进行复合材料与对偶为AISI 52100钢的销-盘式磨损试验.结果显示,当Al/SiC和Al/MoS2复合材料中增强相的最佳含量分别为10 vol％和2 vol％时,材料的磨损率最低;而Al/10SiC/2MoS2复合材料的磨损率和摩擦因数最低.扫描电镜观察表明,在纯铝中加入MoS2颗粒后,材料的主要磨损机理由粘着磨损转变为以磨粒磨损为主.对于Al/SiC和Al/SiC/MoS2复合材料,其主要的磨损机理为轻微的剥层磨损.Al/SiC/MoS2复合材料与Al/SiC复合材料的摩痕和磨损表面接近,表明SiC颗粒在这两种复合材料摩擦学行为中起主导作用.%In order to improve dry sliding wear resistance of pure aluminum against steel, aluminum-based composites reinforced with different contents of SiC, MoS2 and SiC/MoS2 particles were synthesized by press and sintering of the corresponding powder mixtures. The microstructural evaluations showed a dense microstructure which were in good agreement with the result of density and hardness measurements. The results of pin on disk wear tests performed against an AISI 52100 steel pin at a constant load and sliding velocity showed that there was a critical content for both types of the reinforcements at which the lowest wear rate was obtained, i.e. 10 vol.％ and 2 vol.％, respectively, for Al/SiC and Al/MoS2 composites. However, the lowest wear rate and friction of coefficient were attained for Al/10SiC/2MoS2 hybrid composite. According to the scanning electron microscope observations, the predominant wear mechanism was changed from adhesion to abrasion mostly when MoS2 particles were incorporated in the pure aluminum. Mild delamination was identified as the main wear mechanism for Al/SiC and Al/SiC/MoS2 composites. The frictional traces and worn surfaces of Al/SiC/MoS2 composites approached to those of Al/SiC composites, indicating the dominant role of SiC particles in tribological behavior of the hybrid composites.