微/纳米复合涂层的耐空蚀性能

Cavitation Resistance of Micro/Nano-Composite Coating

为提高流体机械的耐空蚀性能,模拟实际工况,利用转盘式磨损试验装置研究了涂覆微/纳米复合涂层及另外4种传统表面处理方法处理的45钢的耐空蚀性能;采用失重法和扫描电镜(SEM)对空蚀磨损结果进行了分析。结果表明:5种试件的空蚀磨损机理基本相同,主要是材料表面在微射流的反复冲击下,产生塑性变形、疲劳凹坑和坑边缘的塑性堆积,从而导致材料的流失;与4种传统表面处理方法相比,微/纳米复合涂层的耐空蚀性能最好,空蚀磨蚀30 h后,基本没有失重。

Plain carbon steel (45 steel) was coated with micro/nano-composite coating,and other four kinds of surface-modification techniques were also used to treat 45 steel for comparison. A rotary abrasion tester was performed to evaluate the cavitation resistance of the surface- modified carbon steel under simulated real working conditions. The wear mass loss of the surface-modified carbon steel was determined by weight loss method,and the worn surface morphology of the surface-modified carbon steel was observed with a scanning electron microscope. Results showed that carbon steels surface-modified by five different techniques underwent similar cavitation mechanism. Namely, they were all dominated by plastic deformation,fatigue pits and pit edge plastic accumulation which resulted in mass loss of material. As compared to the carbon steel surface-modified by conventional techniques,the one coated with micro/nano-composite coating had the best cavitation resistance and was nearly free of weight loss after 30 h of cavitation.