目的 提高 Ni-P 镀层的硬度。 方法 在化学镀 Ni-P 过程中添加 SiO2 微粒,形成 Ni-P-SiO2 复合镀层,研究施镀温度、微粒添加量和镀后热处理温度对复合镀层微观结构及硬度的影响。 结果 复合镀层含非晶结构 Ni 和 SiO2 相。 随施镀温度的升高及 SiO2 微粒添加量的增加,镀层表面变得均匀、致密且硬度升高,显微硬度最高达 355HV;当施镀温度超过 80 ℃ ,微粒添加量超过 10 g/ L 时,镀层表面均匀性变差,硬度下降。 经热处理后,镀层向晶态转变,热处理温度达到 300 ℃时开始析出 Ni3P 相,镀层的显微硬度随热处理温度的升高而升高。 结论 当施镀温度为 80 ℃ 、微粒添加量为 10 g/ L 时,所得复合镀层的性能较为优异,热处理可进一步提高复合镀层的硬度。

Objective In order to improve the hardness of single electroless plating Ni-P coatings, SiO2 particles were incorporated into the plating to form Ni-P-SiO2 composite coating. Methods The effects of plating temperature, concentration of SiO2 particle and temperature of heat treatment on the structure and hardness of the deposits were analyzed. Results It was found that amorphous Ni and high content of SiO2 phase were detected in the composite coating. With the increase of plating temperature and concentration of SiO2 particle, the coating became more homogeneous and dense, and exhibited increased hardness till 355HV. However, the coating surface was rough and porous, and the hardness decreased when the plating temperature was above 80 ℃ and the particle concentration was higher than 10 g/ L. After heat treatment, the coating was transformed to crystalline and the coating hardness was raised. The Ni3P phase appeared when the coating was heated at 300 ℃ for 1 h. Conclusion When the temperature was 80 ℃ and the concentration of SiO2 particle was 10 g / L , the performance of composite coating was the best. The microhardness of coating raised with the increasing temperature of heat treatment.