稀土掺杂WSi_2/MoSi_2材料的合成及其性能

Synthesization and Properties of Rare Earth Doping WSi_2/MoSi_2 Composites

采用自蔓延高温合成(SHS)和机械合金化(MA)方法复合制备了稀土质量分数为0.2%-2.0%的WSi2/MoSi2复合材料.利用MRH-5A型环-块式摩擦磨损试验机测定了复合材料试样与CrWMn钢在油润滑条件下的滑动磨损性能,研究了稀土含量对材料的微观结构、力学性能以及摩擦学性能的影响.结果表明:稀土增强的WSi2/MoSi2复合材料具有细晶组织结构,较高的抗弯强度、硬度和断裂韧性以及较好的耐磨性能,在稀土质量分数为0.5%-0.8%时,复合材料具有最佳的力学性能和摩擦学性能.基体的致密化及强化有利于降低其摩擦磨损.此外,采用SHS+MA工艺可在低的烧结温度获得高致密度的复合材料.

WSi2/MoSi2 composites reinforced by rare earth with the content of 0.2-2.0% were synthesized using a combination technique of self-propagating high-temperature synthesis （SHS） and mechanical alloy （MA）. The wear performances of samples above and the CrWMn rings were measured under lubrication condition using a MRH-5A type ring-block wear tester. The effects of different content of rare earth on the microstructure, mechanical and wear prop- erties of composites were discussed. The results show that the composite synthesized by rare earth has finer microstructure, higher flexural strength, higher fracture toughness and hardness, and better wear resistance. When the content of rare earth is 0.5-0.8%, the composite has the best mechanical and tribological properties. The densification and reinforcement of the matrix are beneficial to reduce the friction and wear of WSi2/MoSi2 composite. In addition, higher density composites can be obtained at the low sintering temperature using a SHS and MA process.