A Ni–P–(sol)Al₂O₃ coating was prepared on the surface of Q235 steel by direct-current electrodeposition. This method was combined with sol-gel and electrodeposition technique, instead of the traditional nanopowder dispersion, to prepare highly dispersible oxide nanoparticle-reinforced composites. The effects of temperature, pH value, and current density and Al₂O₃ sol on the hardness of composite coating were investigated. The coating surface morphology and structure were characterized by scanning electron microscopy and energy dispersive spectroscopy, respectively. The corrosion resistance of coatings in the presence of intermediate layers was evaluated by electrochemical measurement in 3.5% NaCl solution by open-circuit potential measurement at room temperature. The hardness and wear resistance of the coating were measured by a microindentation instrument and friction wear machine, respectively. The results showed that Al₂O₃ sol can effectively improve Ni–P alloy coating structure and refine grain. When the bath temperature was 55°C, the pH value was 4.5, the amount of sol was 80 mL/L, the current density was 1 A/dm², and the hardness of the nanosol coating was 569 HV. Compared with Ni–P, the friction coefficient increases slightly, but the wear rate was only . The corrosion resistance was also better than that of Ni–P coating.

中文翻译：

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电沉积制备溶胶增强的Ni-P–Al2O3纳米复合涂层

通过直流电沉积在Q235钢表面制备了Ni–P–（sol）Al ₂ O ₃涂层。该方法与溶胶-凝胶和电沉积技术相结合，代替了传统的纳米粉体分散体，从而制备了高度分散的氧化物纳米颗粒增强复合材料。温度，pH值，电流密度和Al ₂ O _3的影响研究了溶胶对复合涂层硬度的影响。分别通过扫描电子显微镜和能量色散光谱来表征涂层表面的形态和结构。通过在室温下通过开路电势测量在3.5％NaCl溶液中的电化学测量来评估存在中间层的涂层的耐腐蚀性。涂层的硬度和耐磨性分别通过微压痕仪和摩擦磨损机测量。结果表明，Al ₂ O ₃溶胶可以有效改善Ni-P合金的镀层结构和细化晶粒。浴温为55℃时，pH值为4.5，溶胶量为80mL / L，电流密度为1A / dm ^2。，纳米溶胶涂层的硬度为569 HV。与Ni-P相比，摩擦系数略有增加，但磨损率仅为。耐蚀性也比Ni-P涂层好。