周辰 孙会来 侯保振 常文杰 公彦刚

摘要： 文中对NiAl/3Cr18Mo电弧喷涂涂层的组织与性能进行了对比研究。利用超景深三维显微系统对涂层的组织结构进行观察、对性能进行分析，利用电子显微硬度仪测量涂层的表面硬度。结果表明，喷涂过程中电流和电压的变化对该涂层组织和性能的影响较为明显;当电流和电压较低时，喷涂丝材熔化不充分，熔滴尺寸较小冷凝速度快，熔融粒子与试样之间、熔融粒子与熔融粒子之间不能够均匀的结合，导致涂层结合力较低，涂层硬度也比较小;随着电流和电压的逐步升高，各项组织和性能得到改善，但电流和电压达到一定数值后涂层硬度不再增大。确定了最佳的工艺参数，当喷涂电压为32 V、电流为200 A时，制备出的纯Mo涂层沉积率较高且具有较好的组织和综合性能，其中涂层表面硬度287 HV0.5、粗糙度R为2.22 μm。

关键词： 电弧喷涂; NiAl/3Cr18Mo复合涂层; 电流; 电压

中图分类号： TG 47

Abstract： In this paper， the microstructure and properties of NiAl/3Cr18Mo arc spraying coating were compared. The microstructure and properties of the coating were observed and analyzed by the three-dimensional superdepth microscopy system， and the surface hardness of the coating was measured by the electron microohardness tester. The results showed that the changes of current and voltage during the spraying process had obvious effects on the structure and properties of the coating. When the current and voltage were low， the spraying wire was not fully melted， the droplet size was small and the condensation speed was fast， the liquid metal droplet and the matrix material， the metal droplet and the metal droplet could not form a uniform were meticulous combination， the coating adhesion was low， the coating hardness was small. With the gradual increase of current and voltage， the structure and properties of the coating were improved， but the hardness of the coating did not increase after the current and voltage reached a certain value. The optimum process parameters were determined. When the spraying voltage was 32 V and the current was 200 A， the pure Mo coating had higher deposition rate and better microstructure and comprehensive properties， and the surface hardness of the coating was 287 HV0.5 and roughness was 2.22 μm.

Key words：   arc spraying; NiAl/3Cr18Mo composite coating; current; voltage

0 前言

电弧喷涂是喷涂技术[1-2]的常用方式，在工农业中应用广泛，特别是装饰、耐磨和防腐方面应用频繁。对于磨损严重、无法继续使用的花键、电机转子轴以及汽车曲轴[3]等机械零部件，通过电弧喷涂方式进行修复的效果良好，费用占直接换新件费用的30%左右。喷涂选用耐磨性较好的材质，不仅能保证工件在修复后再次应用，其生命周期也有所延长，具有明显的经济效益，因此研究电弧喷涂技术，对提高其组织性能有十分重要的意义。

目前对电弧喷涂技术往往集中在不同材质的选用及原材料的创新上。……