【作者】 宫玉梅；

【导师】 王殿龙；

【作者基本信息】 哈尔滨工业大学 ， 化学工程与技术， 2009， 硕士

【摘要】 纳米化学复合镀层是纳米材料技术与化学复合镀技术结合的结果,是化学复合镀技术发展中又一次质的飞跃。本文对镍基合金纳米化学复合镀工艺及镀层性能进行了研究。论文首先研究了主盐、还原剂、络合剂、pH值、温度对镀液的镀速的影响。论文还对不同配方镀液的稳定性进行了研究,着重分析了不同分散方法对粒子分散性能的影响,结果表明,短时间内高频率的超声波使粒子分散的更均匀,但是随着时间的延长,两种频率（40kHz/59kHz）使粒子分散的效果几乎相同。表面活性剂的加入对粒子分散也有很好的效果。利用分光光度法测定复合镀层中粒子含量,结果表明,随着加入粒子含量的增多,镀层中纳米粒子的复合量增大,但增速逐渐缓慢。确定纳米Al₂O₃粒子最佳加入浓度为24g/L,此时对应镀层中粒子的复合量为8.97%。论文重点研究了纳米化学复合镀层的硬度,孔隙率,耐蚀性,耐磨性等性能,结论如下:通过热处理实验,得到镀层硬度在热处理温度为550℃时达到最大,Hv为1168,当热处理温度超过600℃时,镀层硬度开始降低。利用SEM-EDX等仪器观测镀层外观,并利用电化学阻抗谱实验（EIS）考察镀层的耐蚀性。结果表明纳米Al₂O₃的加入使镀层的孔隙率降低,从而增强了镀层耐腐蚀性。但是纳米Al₂O₃添加量过多会造成粒子的团聚,镀层的孔隙率先减小后增大。电化学阻抗谱实验结果表明,纳米复合镀层和亚微米复合镀层的耐蚀性都要好于Ni-P镀层,并在镀液中粒子添加量为24g/L时耐蚀性能最好。热处理并不能提高复合镀层的耐蚀性。在磨损试验机上测定镀层的摩擦学性能并与普通Ni-P镀层对比,复合镀层的摩擦系数（0.5）在测试条件下要小于Ni-P镀层（0.57）,说明复合镀层耐磨性好于Ni-P镀层。更多还原

【Abstract】 Nano-electroless composite coating is the perfect combo of the Ni-alloy base nano-material technology and electroless composite technology. It is a huge improvement of electroless composite. This article puts the focus on the technics of Nano-electroless composite deposition and performances of composite Ni-P/Al₂O₃ alloy.The affection of main salt, reducing agent, complex agent, pH and temperature to the plating rate was studied. Find out that with the increase of main salt, reducing agent and complex agent, the plating speed will also be increased. The stability of different plating solution was studied as well as the affection of the decentralization performance when using different dispersing method. The result indicated that by extending the ultrasonic timing, the particles will be dispersed well, and the corrosion resistance will be better. Higher frequency is much better to decentralization in a short time but when we prolong the time, there is no obvious difference between the two frequencies. The decentralization is better with surface active reagent.A spectrophotometer was used to check the particles content in composite alloy. The result shows that by adding more particles into the solution, the nano-particles content in the layer will be increased and the increasing speed gradually down low. The best amount of nano-Al₂O₃ for this testing solution is 24g/L.The composite coating we get from this solution contains 8.97% nano-Al₂O₃ paricles and it has better corrosion resistance.The performances of nano-electroless composite coating, such as hardness, corrosion resistance, hole ratio and wearability were emphasizely studied in this paper. Through out heat treatment, coating hardness will get to a maximum when the temperature reaches 550℃,Hv 1168, and it will drop when temperature higher than 600℃. SEM-EDX was used to observe the morphology and EIS was used to investigate the corrosion resistance. The results shows that by adding nano-Al₂O₃ the hole ratio of the coating come down, which could improve the coating corrosion resistance. But too much nano-Al₂O₃ would cause polymerization which will increase the hole-ratio. EIS shows that both nano-Al₂O₃ and sub-micro-Al₂O₃ composite coating has better corrosion performance than Ni-P alloy. The optimum amount of particles in solution is 24g/L.Corrosion performance of composite coating was poorer after heatment. The wearability of nano-Al₂O₃ composite coating and normal Ni-P alloy were tested on a wear and tear machine, and we can see the rub coefficient of composite coating （0.5） is smaller than the normal Ni-P coatings （0.57）, which means composite coating has better wearability.更多还原