目的 通过在超音速火焰喷涂(HVAF)的Ni60涂层制备中引入镀镍金刚石，并优化摩擦副材料，以提升涂层的耐磨性，延长锁渣阀的使用寿命。方法 采用HVAF技术制备了不同镀镍金刚石质量分数的金刚石/Ni60复合涂层。利用光学显微镜、扫描电镜、X射线衍射和能谱分析等手段对涂层的微观结构和物相进行分析。通过往复摩擦磨损实验，评估涂层的耐磨性，研究不同摩擦副条件下的磨损行为。结果 采用HVAF超音速火焰喷涂工艺可以制备得到完整且结合良好的金刚石/Ni60复合涂层，金刚石颗粒均匀分布于Ni60合金相中，部分颗粒发生破碎。Ni60及3种金刚石/Ni60复合涂层的孔隙率分别为0.647%、0.962%、0.913%、1.555%。4种涂层在氧化铝磨球下的相对磨损量分别为0.06、4.61、4.54、16.2，而在氮化硅磨球下的相对磨损量分别为0.01、1.33、2.50、0.33。在氧化铝和氮化硅磨损条件下，摩擦因数曲线均呈现先增加后减小的趋势。结论 适量金刚石的加入，显著提高了涂层的硬度和耐磨性，但金刚石的含量过高会导致涂层的孔隙率增大，从而降低涂层的耐磨性能。在金刚石的质量分数为37.5%时，金刚石/Ni60复合涂层的耐磨性能最佳。氮化硅作为配套密封面材料，与复合涂层具有更好的兼容性。氮化硅-金刚石/Ni60复合涂层的磨损机制为磨粒磨损、氧化磨损及一定的疲劳磨损。氧化铝-金刚石/Ni60复合涂层的磨损机制主要是磨粒磨损和少许黏着磨损，以及一定的疲劳磨损。

The work aims to enhance the wear resistance of Ni60 coatings prepared by HVAF supersonic flame-spraying technology by incorporating nickel-plated diamond particles and optimizing the friction pair materials, thereby extending the service life of scum ball values. The scum ball values are critical components in industrial processes, particularly coal chemical industry, where they are subject to severe wear due to the abrasive nature of slag. Therefore, improving their wear resistance is essential for reducing maintenance costs and downtime. The HVAF technology was employed to deposit diamond/Ni60 composite coatings with varying mass fractions of diamond particles. The supersonic flame spraying process with compressed air as a combustible gas has the following process parameters, including the powder feeding volume of about 3 g/s, the spraying distance of 260 mm, the compressed air pressure of 78.4 psi (1 psi=6 894.757 29 Pa), the propane fuel pressure of 76.5 psi, and the nitrogen gas flow rate of 22 L/min. By this HVAF process, diamond/Ni60 composite coatings that were intact and well-bonded were successfully prepared. The phases in the coatings, except for diamond, were essentially consistent with the original Ni60 powder. The microstructure and phase composition of the coatings were characterized with optical microscopy, scanning electron microscopy (EM-30AX+), X-ray diffraction (DX-2700BH), and energy-dispersive spectroscopy. The reciprocating friction and wear test was completed on a multifunctional wear tester (MS M9000). The wear resistance of the coatings was evaluated through reciprocating friction and wear tests under different friction pair materials, specifically alumina and silicon nitride balls, to select suitable coating compatible materials in scum ball values. The diamond particles were evenly distributed throughout the Ni60 alloy matrix, with some nickel-plated diamond particles exhibiting signs of fragmentation, which was a common phenomenon in thermal spray processes due to the high impact forces and temperatures. The porosity levels of Ni60 and three diamond/Ni60 composite coatings were 0.647%, 0.962%, 0.913%, and 1.555%, respectively. The relative wear values of the four coatings tested against alumina balls were 0.06, 4.61, 4.54, and 16.2, indicating that the addition of diamond particles significantly reduced the wear compared to the pure Ni60 coating. During the test against silicon nitride balls, the relative wear values were 0.01, 1.33, 2.50, and 0.33, respectively. The friction coefficient curves under both alumina and silicon nitride wear conditions exhibited an initial increase followed by a decrease. The decrease in friction coefficient with alumina was attributed to the rolling and sliding of wear debris, which helped to reduce friction, while the decrease in silicon nitride was due to its self-lubricating properties. The addition of an appropriate amount of diamond particles significantly improves the wear resistance of the Ni60 coating. However, an excessive amount of diamond particles leads to an increase in porosity, thereby reducing wear resistance. The diamond/Ni60 composite coating with a diamond content of 37.5% demonstrates the best wear performance. Silicon nitride is considered to be a more suitable friction pair material for the composite coating due to its self-lubricating characteristics. The wear mechanism of the silicon nitride-diamond/Ni60 composite coating is primarily abrasive wear and oxidative wear, with some fatigue wear. The wear mechanism of the alumina-diamond/Ni60 composite coating is mainly abrasive wear with a small amount of adhesive wear and some fatigue wear.