稀土强韧化MoSi2材料的摩擦学性能

采用高温自蔓延和真空烧结合成了含0.8%（质量分数）稀土/MoSi2复合材料。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KYKY2800型扫描电镜分析了其磨损表面形貌,探讨了该材料的磨损机制。结果表明：在干摩擦同等条件下,稀土/MoSi2复合材料比纯MoSi2材料具有更好的抗磨损性能,其磨损率比纯MoSi2至少降低了68%。低速（200r/min）时,RE/MoSi2复合材料的磨损机制主要是粘着磨损,随着载荷的增加,粘着磨损脱落更为严重;在高速（400r/min）和低载荷（78N）下,RE/MoSi2复合材料的磨损机制仍以粘着磨损为主,在重载荷（274N）下,RE/MoSi2复合材料的磨损机制主要为粘着磨损和疲劳脆性断裂。

Tribological Behaviors of MoSi2 Strengthened and Toughened by Rare Earth

The MoSi2 matrix composite reinforced by mass fraction 0.8% rare earth was prepared by self-propagating high-temperature systhesis(SHS) and high-temperature sintered.The wear properties of the composite against quenched and tempered steel were tested on a MRH-5 A type wear test machine.The wearing surface morphology of the composite was observed by using a KYKY2800 SEM with EDS and wear mechanism was discussed.The result shows that the RE/MoSi2 composite has better wear properties than simple MoSi2 under dry friction.The wear rate of the composite is 68% lower than that of the simple MoSi2.The wear mechanism of the RE/MoSi2 composite is mainly grain abrasion and slightly adhesive wear at low load.With load increasing,the lost of adhesive wear becomes much heavier.The wear mechanism of the RE/MoSi2 composite is mainly grain abrasion.The abrasion mechanism of the composite was adherence abrasion and brittle fracture with load increasing.