【作者】 胡正兵；

【导师】 黄根良；

【作者基本信息】 江苏大学 ， 材料学， 2005， 硕士

【摘要】 化学复合镀作为一种优良的表面处理技术,由于其具有工艺简单、镀层均匀、性能优良等特点,近些年来得到了广泛地研究和应用。纳米材料的特殊性使得其具有比普通材料高得多的强度和硬度,以及一些独特的性能,正逐渐成为当今材料领域的研究热点之一。本文结合这两项技术的特点,在化学镀层中复合纳米氧化铝和PTFE粒子,制备出性能优良的多元化学复合镀层。 本文研究了pH值、温度对镀液的稳定性、镀速和镀层磷含量的影响,并且确定了它们的最佳工艺参数;研究了镀液中颗粒添加量、颗粒尺寸对镀层中颗粒含量及镀层性能的影响,并利用正交试验设计方法确定了多元复合镀液中两种颗粒的最佳添加量。 研究了分散方法对化学复合镀层性能的影响。对比不同分散方式和分散强度对复合镀层性能的影响,着重研究了多元复合镀液中表面活性剂的种类以及添加量,并确定了它们的最佳工艺参数。 运用XRD、SEM、显微硬度检测等手段分析了化学复合镀层的表面形貌、组织结构、显微硬度、耐磨性等;同时对镀层的结合力、耐蚀性等方面也进行了研究;此外,还考察了热处理对镀层组织结构和性能的影响。将多元化学复合镀层Ni-P-PTFE-Al₂O₃与Ni-P合金镀层、Ni-P-Al₂O₃微米复合镀层、Ni-P-Al₂O₃纳米复合镀层及Ni-P-PTFE复合镀层进行对比,结果表明Ni-P-PTFE-Al₂O₃复合镀层的综合性能要优于普通Ni-P镀层和单颗粒复合镀层。 同时,本文对化学复合镀的共沉积机理、镀液稳定性机理作了探讨;分析讨论了化学镀液中颗粒的分散机理;并从动力学角度研究了化学镀液的沉积速度一般规律。更多还原

【Abstract】 As a kind of excellent treatment technology with simple technics, homogeneous and fine coatings, electroless composite plating is getting studied and applied widely. The special performance of nanometer material makes it have much more intensity and hardness than the common, and become one of the hotspots in material field. Combining the two technology above, this dissertation studied the preparation of electroless multi-composite coating compounded with nano Al₂O₃ powder and PTFE.This paper studied the influence of bath temperature and pH value on the stability of bath, deposition rate and the ratio of P in the coating; and found out their proper process conditions. The influence of the concentration and dimension of the powder added in bath on the ratio of particles in coatings and the properties of coatings was also studied; and the value of these parameters were determined by orthogonal test.The effects of various dispersing methods on the properties of coatings were studied in the paper. According to the comparison among the different effects of dispersing methods and their intensity on the properties of coatings, and the research of the categories and concentration of the surfactants in bath, the preferable value of these parameters was found out.The microstructure, microhardness, wear resistance capability, etc. of coatings were analysed by XRD, SEM and other instruments. Moreover, the binding strength and corrosion resistance capability of coatings, and the influence of heat treatment on the microstructure and properties of coatings were also studied. The results of the comparison between the composite coating Ni-P-PTFE-Al₂O₃ and Ni-P, M-P-Al₂O₃ （μ m）, Ni-P- Al₂O₃（nm）, Ni-P-PTFE indicated that the integrated performance was superior to Ni-P and other composite coatings compounded with single particle.In addition, the paper made a preliminary discussion on the mechanism of electroless composite codeposition and stability of bath; and analysed the dispersing mechanism of the particles in the bath. Meanwhile the common law of the deposition rate was studied on the dynamic aspects.更多还原