GNP/SiC/Al复合材料的常温及高温磨损行为研究

Wear Behavior of GNP/SiC/Al Composites at Room and Elevated Temperatures

摘要:

采用高能球磨法结合粉末冶金工艺制备了SiC和石墨烯纳米片（GNP）混杂增强铝基（GNP/SiC/Al）复合材料。通过SEM、TEM、拉伸试验机和摩擦试验机等对GNP/SiC/Al复合材料的微观组织、力学和磨损性能进行表征和分析，并与灰铸铁材料（HT250）进行对比。结果表明，SiC与GNP在基体中均匀分散，复合材料的常温及350 ℃下抗拉强度分别达到287和101 MPa。常温磨损中，复合材料耐磨性能低于灰铸铁，2种材料均呈现粘着磨损和磨粒磨损机制。高温磨损中，复合材料耐磨性显著优于灰铸铁。灰铸铁表现为粘着磨损和磨粒磨损机制，而复合材料以粘着磨损为主。SiC与GNP的高温钉扎效应、GNP的自润滑特性以及机械混合层的形成是GNP/SiC/Al复合材料高温耐磨性能优异的主要原因。

Abstract:

SiC and graphene nano-platelet (GNP) hybrid reinforced aluminum matrix (GNP/SiC/Al) composites were fabricated by high-energy ball milling combined with powder metallurgy process. The microstructure, mechanical properties, and wear performance of GNP/SiC/Al composites were characterized by SEM, TEM, universal tensile testing machines, and tribometers, with comparative analysis against gray cast iron (HT250). The results indicate that when SiC and GNP are uniformly dispersed in the matrix, the tensile strengths of composites are 287 and 101 MPa at room temperature and 350 ℃, respectively. During room temperature wear tests, the wear resistance of composites is lower than that of HT250. Both materials exhibit adhesive and abrasive wear mechanisms. Under high-temperature wear conditions, the wear resistance of the composites is better than that of HT250. HT250 exhibits adhesive and abrasive wear mechanisms, the composites are mainly characterized by adhesive wear. The exceptional high-temperature wear resistance of GNP/SiC/Al composites is attributed to three primary mechanisms: the high-temperature pinning effect of SiC and GNP; the self-lubricating properties of GNP; the formation of mechanically mixed layers during wear.