To improve the wear resistance of type 45 steel surfaces, Ni–Mn alloy coatings are prepared through electrodeposition under different sodium citrate concentrations based on which SiC particles of varying concentrations are added to prepare Ni–Mn–SiC composite coatings. The coatings are characterized by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, microhardness testing, surface roughness meter, composite material surface performance testing, and laser scanning confocal microscopy. The results show that adding an appropriate concentration of sodium citrate into the electrolyte can significantly improve the Mn content in the coatings; however, an excessively high concentration increases the residual stress of the coatings and induces cracks on the surface. When the sodium citrate concentration is 40 g/L, the microhardness and wear resistance of the coatings are optimum. The average microhardness of the Ni–Mn alloy coatings is 522.8 HV_0.05, and the minimum scratch area of the wear mark is 9526.26 μm². The addition of SiC particles improves the surface integrity of the composite coatings and further improves the microhardness and wear resistance of the coatings. The composite coating has a maximum average microhardness value of 648.7 HV_0.05 for SiC particle concentration of 4 g/L; this value is nearly 25% higher than that of pure Ni–Mn alloy coatings; the minimum scratch area of the wear mark is reduced to 7160.46 μm².

中文翻译：

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电沉积Ni-Mn-SiC复合涂层的耐磨性

为了提高45型钢表面的耐磨性，通过在不同柠檬酸钠浓度下进行电沉积来制备Ni-Mn合金涂层，然后在其中添加不同浓度的SiC颗粒以制备Ni-Mn-SiC复合涂层。通过扫描电子显微镜，能量分散光谱，X射线衍射，显微硬度测试，表面粗糙度仪，复合材料表面性能测试和激光扫描共聚焦显微镜对涂层进行表征。结果表明，在电解液中添加适当浓度的柠檬酸钠可以显着提高涂层中的Mn含量。但是，过高的浓度会增加涂层的残余应力，并在表面产生裂纹。当柠檬酸钠浓度为40 g / L时，涂层的显微硬度和耐磨性最佳。镍锰合金镀层的平均显微硬度为522.8 HV_0.05，磨损标记的最小划痕面积为9526.26微米²。SiC颗粒的添加改善了复合涂层的表面完整性，并进一步改善了涂层的显微硬度和耐磨性。当SiC颗粒浓度为4 g / L时，复合涂层的最大平均显微硬度值为648.7 HV _0.05。该值比纯镍锰合金涂层的值高近25％。磨损标记的最小划痕面积减小到7160.46微米²。