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超音速激光沉积技术(SLD)是一种将激光辐照与冷喷涂相结合的新型涂层制备工艺,因其结合了激光技术和冷喷涂技术的优势,能够沉积冷喷涂难以沉积或不可能沉积的材料。利用超音速激光沉积技术在中碳钢基材上成功制备了Ni60涂层,并采用扫描电子显微镜(SEM)、能谱分析(EDS)、X射线衍射(XRD)、显微硬度测试等手段对涂层的沉积效率、显微组织成分、结合机理以及显微硬度进行了表征分析。研究结果表明:随着激光加热温度升高,涂层沉积厚度增加,表面球型凹坑逐渐减少;Ni60涂层保持了冷喷涂固态沉积的特征,显微组织结构以及相组成与原始粉末相一致;激光加热导致Ni60沉积层与基体间同时存在机械咬合与冶金结合;涂层的平均显微硬度为867 Hv0.3,比原始粉末提高8%~10%,沉积过程产生了冷作硬化。
Sonic Laser Deposition (SLD) is a novel coating process that combines laser irradiation with cold spray. It combines the advantages of laser technology with cold spray technology to enable cold spray deposition to be difficult or impossible to deposit s material. The Ni60 coating was successfully prepared on a medium carbon steel substrate by supersonic laser deposition. The surface morphology of the Ni60 coating was characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and microhardness test The coating deposition efficiency, microstructure, bonding mechanism and microhardness were characterized. The results show that with the increase of laser heating temperature, the coating deposition thickness increases and the surface spherical pits decrease gradually. The Ni60 coating retains the characteristics of cold spray solid state deposition. The microstructure and phase composition of the Ni60 coating are consistent with the original powder Laser heating led to the simultaneous mechanical bite and metallurgical bonding between the Ni60 deposit and the substrate. The average microhardness of the coating was 867 Hv0.3, which was 8% -10% higher than that of the original powder. The cold hardening occurred during the deposition.