32Mn25Al3Cr5RE耐空蚀性能研究

报道了32Mn25Al3Cr5RE不锈钢振动空蚀现象和机理。试验结果表明，不同状态32Mn25Al3Cr5RE的耐空蚀性能比1Cr18Ni9Ti高3～7倍。

微/纳米复合涂层的耐空蚀性能

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。

Ti6Al4V合金热浸镀铝的空蚀行为研究

采用热浸镀法在Ti6Al4V合金表面制备Ti Al3涂层,并在550℃真空保温5 h。对热浸镀后材料与Ti6Al4V合金进行了空蚀试验对比。通过X射线衍射仪、扫描电镜及显微硬度测量等手段研究了涂层的组织形态和耐空蚀性能。结果表明:热浸镀铝比Ti6Al4V合金空蚀累积质量损失低,具有更好的抗空蚀性能,这与Ti6Al4V合金表面形成的Al3Ti的强化作用有关。热浸镀铝和Ti6Al4V合金空蚀20 h后横截面显微硬度都降低,发生了加工软化现象,使得材料表面逐渐脱落。

离心式注水泵火焰超音速喷涂金属陶瓷涂层性能试验研究

通过研究离心式注水泵的使用工况及失效机理,设计了一种火焰超音速喷涂工艺制备的以镍、钴合金为主的复合金属陶瓷涂层提高离心式注水泵叶轮的泵效,对涂层进行金相观察、显微硬度分析、涂层结合强度试验及耐空蚀性能测试,结果表明,镍基金属陶瓷涂层与基体结合强度高,抗空蚀性能优良。

Effects of surface roughness of substrate on properties of Ti/TiN/Zr/ZrN multilayer coatings

Ti/TiN/Zr/ZrN multilayer coatings were deposited on Cr_17Ni_2 steel substrates with different surface roughnesses by vacuum cathodic arc deposition method. Microstructure, micro-hardness, adhesion strength and cross-sectional morphology of the obtained multilayer coatings were investigated. The results show that the Vickers hardness of Ti/TiN/Zr/ZrN multilayer coating, with a film thickness of 11.37 μm, is 29.36 GPa. The erosion and salt spray resistance performance of Cr_17Ni_2 steel substrates can be evidently improved by Ti/TiN/Zr/ZrN multilayer coating. The surface roughness of Cr_17Ni_2 steel substrates plays an important role in determining the mechanical and erosion performances of Ti/TiN/Zr/ZrN multilayer coatings. Overall, a low value of the surface roughness of substrates corresponds to an improved performance of erosion and salt spray resistance of multilayer coatings. The optimized performance of Ti/TiN/Zr/ZrN multilayer coatings can be achieved provided that the surface roughness of Cr_17Ni_2 steel substrates is lower than 0.4μm.