热处理对超音速等离子喷涂Mo-W涂层性能的影响

Effect of Heat Treatment on Properties of Mo-W Coatings Prepared by Supersonic Plasma Spraying

采用超音速等离子喷涂技术在45Cr Ni MoVA钢表面制备Mo-W合金涂层,对涂层进行了从400～1000℃不同温度条件下的热处理,对不同处理状态下的涂层进行了电弧烧蚀试验。利用场发射扫描显微镜(SEM)、电子能谱仪(EDS)分析涂层组织和成分,利用维氏显微硬度计测试硬度,利用四探针电阻仪测定涂层电阻率。结果表明:热处理工艺可以改变合金元素的固溶度,但并不能明显消除喷涂层中孔隙等宏观缺陷;随着热处理温度升高,Mo-W喷涂层的显微硬度由563.2 HV0.1下降为460.6 HV0.1(1000℃),涂层的导电率呈现缓慢增加趋势;热处理温度为1000℃时涂层导电率最高,为6.42%IACS。在1000℃以下进行热处理,Mo-W涂层的耐电弧烧蚀性能有所提升。

Mo-W coating was prepared by using supersonic plasma spraying technology on the surface of 45 CrNiMoVA steel. The coatings were heat treated from 400 to 1000℃ at different temperatures, the arc erosion tests of the coatings under different treatment conditions were carried out. The microstructure and composition of the coating were analyzed by using field emission scanning microscope(SEM) and electronic energy spectrometer(EDS), the hardness of the coating was measured by Vickers microhardness tester and the resistivity of the coating was measured by four-probe resistance meter. The results show that, the heat treatment process can change the solid solubility of the alloy elements, but the macroscopic defects such as pores in spray coating can not be eliminated obviously. The microhardness of Mo-W sprayed coating decreases from563.2 HV0.1 to 460.6 HV0.1(1000 ℃) with the increase of heat treatment temperature, the conductivity of the coating shows a slow increasing trend. When the heat treatment temperature is 1000 ℃, the conductivity of the coating is the highest, which is 6.42%IACS. The arc erosion resistance of the Mo-W coating is improved under heating treatment at below 1000 ℃.