在材料保护涂层方面，市场有以热喷涂工艺替代传统电镀工艺的需求，但相应涂层的抗气蚀和耐腐蚀性能依据不足。为此，分别采用超音速火焰喷涂和传统电镀工艺制备了成分相似的镍基涂/镀层。通过XRD衍射仪、超声波气蚀试验和电化学腐蚀实验，对上述涂/镀层的组织结构、抗气蚀以及耐腐蚀性能进行了研究。结果表明：与电镀层相比，热喷涂层的硬度高出约50%，而且其气蚀磨损机制不同，气蚀后涂层表面更加平整，气蚀质量损失仅为电镀层的30%。在3.5%NaCl溶液中对上述涂/镀层进行电化学腐蚀测试，结果显示，热喷涂层的腐蚀电位比电镀层略低，但阻抗更大，且腐蚀电流密度比电镀层小1个数量级。所以，热喷涂工艺制备的涂层相比于电镀层具有更高的硬度、更好的抗气蚀和耐腐蚀性能，可为热喷涂替代传统电镀工艺在材料保护涂层上的应用提供有力支撑。
In the field of material protection coating, there is a market demand for replacing the traditional electroplating process with the thermal spraying process, but supporting information in the aspects of the cavitation and corrosion resistances of corresponding coatings is inadequate. To solve this problem, Nickel - based coatings with similar chemical compositions were prepared respectively by HVOF (High Velocity Oxygen Fuel) thermal spraying and traditional electroplating process. The microstructure, cavitation resistance and corrosion resistance of the thermally sprayed and electroplated coatings were researched by XRD, ultrasonic cavitation test and electrochemical corrosion test. Results showed that the hardness of thermally sprayed coating was about 50% higher than that of the electroplated coating and the cavitation wear mechanisms of these two coatings were different. After cavitation, the surface of thermally sprayed coating was obviously brighter and smoother than that of the electroplated coating, and the cavitation mass loss of thermally sprayed coating was only 30% of that of the electroplated coating. Moreover, the results of an electrochemical corrosion test on these two coatings carried out in 3.5% NaCl solution showed that, comparing with the electroplated coating, the thermal sprayed coating showed slightly lower corrosion potential, larger impedance and one order of magnitude smaller corrosion current density. Therefore, the coating prepared by thermal spraying process had higher hardness, better cavitation resistance and corrosion resistance than electroplated coating. This paper could provide a strong support for the application of thermal spraying instead of traditional electroplating process in the manufacturing of material protection coatings.
