【摘要】 利用等离子熔覆设备堆焊制备了三种不同成分的镍基合金层(Ni46、Ni67、Ni60/35WC),制样后在旋转圆盘空蚀试验机上对制备的合金层进行了空蚀磨损实验.采用SEM、XRD、显微硬度、失重分析法对空蚀前后的合金层进行了对比分析.结果表明:所有堆焊层的失重均大于对比的304不锈钢;SEM形貌观察堆焊层组织中存在缺陷或孔隙,空蚀后组织中的缺陷呈裂纹状发展,因此空蚀伴随着强烈的疲劳损失过程;XRD分析表明空蚀过程诱发了Ni60/35WC表面的相变;另外,空蚀还引起了材料Ni67和Ni60/35WC加工硬化,而Ni46出现了加工软化.更多还原

【Abstract】 Three kinds of Ni-based metal claddings(Ni46,Ni67,and Ni60/35WC)were deposited by the plasma jet cladding process.These cladding samples were then subject to cavitation erosion testing on the rotating disc cavitation test equipment.SEM,X-ray diffraction,micro hardness,and weight loss analysis were exploited to analyze the changes of the materials.The results showed the values of weight loss for all claddings were more than that of stainless steel 304.SEM images showed a large number of cracks occur and propagate under subsurface,for the existence of cavity and the other faults of structure,which significantly decreased the cavitation erosion resistance of the cladding materials.So the cavitation erosion is a typical fatigue failure process.Some new phases appeared and some old phases disappeared on the surface of the Ni60/35WC cladding after cavitation testing by X-ray diffraction.For Ni67 and Ni60/WC,the microhardness values of surface claddings became higher after cavitation and softer for Ni46.更多还原