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目的：初步研究高速电弧喷涂Mo涂层的综合性能,为进一步发展热喷涂Mo涂层制备工艺提供参考。方法利用高速电弧喷涂设备在45 CrNiMoVA钢表面制备Mo涂层,采用场发射扫描电镜、X射线能谱仪、显微硬度测试仪及电子万能试验机等对涂层形貌、成分、显微硬度及结合强度进行表征和测试,并结合断口微观形貌对拉伸断裂机理进行分析。采用CETR-3型多功能摩擦磨损试验机,在润滑条件下对涂层进行不同载荷的摩擦磨损实验,通过磨损体积及表面磨痕微观形貌分析涂层的摩擦磨损性能及机理。结果 Mo涂层具有一定量的微观孔隙,氧化物含量低,与基体结合牢固可靠,平均显微硬度高达416.3 HV0.1,平均内聚强度为22.7 MPa。拉伸断口呈脆性断裂,并伴有半熔融颗粒剥落留下的剥落坑。润滑条件下,涂层在10,30,50 N载荷下的磨损体积分别为1.1×107,4.4×107,5.5×107μm3。结论高速电弧喷涂可成功制备Mo涂层,涂层与基体为机械结合。在润滑条件下,涂层的磨损体积随载荷增大而增大,不同载荷下的磨损机理均以粘着磨损为主。

ABSTRACT:Objective To study the comprehensive properties of Mo coating prepared by high velocity arc spraying, so as to pro-vide some referential value for Mo coating preparation technology. Methods The Mo coatings were prepared on the surface of 45CrNiMoVA steel by the high velocity arc spraying device, tests include microstructure, components, microhardness, bonding-strength were performed by SEM, XRD, micro-hardness test, electromechanical universal testing machine, and the fracture mecha-nism was analyzed through the micro-structure of fracture surface. The lubricative tribological properties under different loads of coating were tested by the CETR-3 multifunctional friction and wear testing machine. The friction properties and wear mechanism were characterized through the wear volume and worn surface. Results The Mo coating presented a certain amount of micro-pores and low content of oxides, the bonding of coating and matrix is reliable without cracks and pores, the average microhardness is 416. 3 HV0. 1, the average cohesive strength is 22. 7 MPa. The tensile fracture surface showed brittle fracture companied with some pits resulted by partial melted particles, and the wear volume were 1. 1×107μm3, 4. 4×107μm3 and 5. 5×107μm3 when under the load of 10 N, 30N and 50 N, respectively. Conclusion Mo coating can be successfully prepared by high velocity arc spraying, the bonding mechanism of coating and matrix is mechanical joint. The lubricative wear test showed that wear volume was increased with the rise of load, and the wear mechanism under different loadings was mainly adhesive wear.