Ni—P-纳米TiO2化学复合镀层的制备

采用化学复合镀在40CrNi钢基体上制备Ni—P-纳米TiO2复合镀层，研究了乳酸，柠檬酸、乙酸钠以及表面活性剂对镀层的沉积速度和显微硬度的影响，并通过正交试验，优化了工艺参数。结果表明：当乳酸的体积分数为3％、柠檬酸的质量浓度为25g/L、乙酸钠的质量浓度为20g／L、表面活性剂为阴离子型时，镀层具有优良的性能，镀速达到了11．55μm／h，镀层镀态显微硬度为550HV。

Preparation of Electroless Ni-P-nano TiO2 Composite Plating

Ni-P-nano TiO2 composite plating were prepared on the 40CrNi steel substrate by electroless composite plating. The effect of the concentrations of lactic acid, citric acid, sodium acetate and the type of surfactants on the deposition rate and microhard- ness of electroless composite coatings was investigated. The process parameters were optimized by orthogonal test. The results indicate that the composite plating has good properties, the depositing speed is 11.55 ~m/h, composite plating microhardness is 550 HV when the volume fraction of lactic acid is 3%, the concentration of citric acid is 25 g/L, the concentration of sodium acetate is 20 g/L, and the surface active agent is anion.