干摩擦条件下稀土-Mo_5Si_3/MoSi_2复合材料的摩擦磨损性能

Wear Behavior of MoSi_2 Matrix Composite Reinforced by Mo_5Si_3 and Rare Earth under Dry Friction

采用高温自蔓延合成了含0.8%稀土-5 at%Mo5S i3/MoS i2复合材料粉末,经冷压和高温真空烧结成试样。在MRH—5A型环-块摩擦磨损试验机上,考察了其与调质45#钢配对时的摩擦磨损特性。运用带有微探针的JSM—5610LV型扫描电子显微镜,观察与分析了其磨损表面形貌和相的组成,探讨了该材料的磨损机理。结果表明:在干摩擦同等条件下,稀土-Mo5S i3/MoS i2复合材料比纯MoS i2材料具有更好的抗磨损性能,其磨损率比纯MoS i2的至少降低了72%。在低pv值时,稀土-Mo5S i3/MoS i2复合材料的主要磨损失效形式为磨粒磨损和轻微粘着磨损;而当pv值≥81.12 N.m/s,则主要为粘着磨损和疲劳断裂。

The MoSi2 matrix composite reinforced by 0.8wt% rare earth and 5at% M%Si3 was prepared by SHS, and then pressed at room temperature and vacuumly sintered at high temperature. The wear properties of the composite against quenched and tempered steel were tested on a MRH-5A type wear test machine. The wearing surface morphology and phase composition of the composite were observed by using a JSM-5610LV SEM with EDS. The wear mechanism of the composite was discussed as well. The results showed that the RMM composite had better wear properties than simple MoSi2 under dry friction. The wear rate of the RMM composite was 72% lower than that of the simple MoSi2. The wear mechanism of the RMM composite was mainly grain abrasion and slightly adhesive wear at low pv value, but adhesive wear and fatigue fracture at pv≥81.12 N · m/s.