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为了提高喷射电沉积纳米镍涂层的性能,采用激光重熔工艺对涂层进行处理,研究了激光重熔对涂层微观组织和性能的影响。用扫描电镜(SEM),X射线衍射仪(XRD)和显微硬度计分析了涂层表面形貌、微观结构和显微硬度,同时对涂层的腐蚀特性进行了考察。结果表明,在优化的工艺参数下,喷射电沉积制备的镍涂层表面比较平整,结合致密,由平均尺寸为13.7 nm的纳米晶颗粒组成,但涂层中仍存在一些孔隙及其他缺陷;经过激光重熔后,熔融区内的晶粒尺寸明显减小,使涂层致密化程度得以提高并使涂层与基体由机械结合变为冶金结合,因此激光重熔处理后涂层的显微硬度明显提高,且其耐腐蚀性能明显优于原喷射电沉积镍涂层。
In order to improve the performance of spray-deposited nano-nickel coating, laser remelting was used to treat the coating, and the effect of laser remelting on the microstructure and properties of the coating was studied. The surface morphology, microstructure and microhardness of the coating were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and microhardness tester. The corrosion properties of the coating were also investigated. The results show that under the optimized process parameters, the surface of Ni coating prepared by spray deposition is relatively smooth and dense, and consists of nanocrystalline particles with an average size of 13.7 nm. However, some pores and other defects remain in the coating. After laser remelting, the grain size in the melting zone is obviously reduced, the degree of densification of the coating is improved, and the combination of the coating and the substrate becomes metallurgical bond by mechanical bonding. Therefore, the microhardness of the coating after laser remelting treatment Significantly improved, and its corrosion resistance was significantly better than the original jet electrodeposited nickel coating.