GNP/SiC/Al复合材料的高温磨损行为及其与灰铸铁的对比研究

High-Temperature Wear Behavior of GNP/SiC/Al Composites and its Comparison with Gray Cast Iron

摘要:

通过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。通过扫描电镜、透射电镜、拉伸试验机和摩擦试验机等设备对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 °C下抗拉强度分别达到287 MPa和101 MPa。常温磨损中，复合材料耐磨性能低于灰铸铁，两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 via high-energy ball milling combined with powder metallurgy. The microstructure, mechanical properties, and wear performance of the composites were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), universal tensile testing machines, and tribometers, with comparative analysis against gray cast iron (HT250). Results indicate uniform dispersion of SiC and GNP within the matrix. The composites exhibited the tensile strengths of 287 MPa and 101 MPa at room-temperature and 350°C, respectively. During room-temperature wear tests, the composites demonstrated inferior wear resistance to HT250, with both materials exhibiting adhesive and abrasive wear mechanisms. Under high-temperature wear conditions, the composites showed significantly superior wear resistance to HT250. While HT250 exhibited adhesive and abrasive wear mechanisms, the composites primarily underwent adhesive wear. The exceptional high-temperature wear resistance of GNP/SiC/Al composites is attributed to three primary mechanisms: (1) the high-temperature pinning effect of SiC and GNP, (2) the self-lubricating properties of GNP, and (3) the formation of mechanically mixed layers during wear.