燃烧合成熔化制备块体纳米结构材料和金属间化合物基复合材料及其摩擦学性能

Combustion synthesized bulk nanocrystalline materials and intermetallic matrix composites and their tribological properties

利用燃烧合成熔化技术在300℃以上加温以及惰性气氛保护条件下熔化制备了晶粒尺寸小于10nm、厚度大于3mm、具有优异力学和抗磨损性能的Ni3Al,Fe3Al,WCx块体纳米结构材料,并且利用此法制备了微观组织特征良好、增强相含量可在较大范围内调整,且具有良好力学和抗磨损性能的陶瓷相增强的铝化物、硅化物基复合材料。燃烧合成熔化技术具有低能耗、低污染和生产效率高等优点。对几类金属间化合物摩擦学性能的研究表明,其磨损性能具有反温度和速度效应,即随温度、速度的升高其磨损量反而下降,磨损机理以微断裂、疲劳磨损为主;复合化、纳米化是提高其抗磨性的有效途径。

Ni_3Al, Fe_3Al and WC bulk nanocrystalline materials with crystal size of less than 10 nm and bulk thickness of 3 mm, which also have excellent mechanical properties and wear resistance, were prepared by combustion synthesis in inert atmosphere and at above 300 ℃. By this means, aluminides, silicates base composites with homogeneous microstructure, adjustable strengthening phase content, good mechanical properties and wear resistance can also been prepared. Therefore, combustion systhesis has the merits of low energy consumption, low pollution and high efficiency. Studies on the wear properties of the above intermetallics show that their wear loss decreases with temperature and velocity increasing, and the wear mechanism are mainly micro-crack and fatigue wear. The wear resistance can be improved by nanocrystallized, composited method.