Preparation Technology Of Ni/Nano-SiC Composite Coatings Electrodeposited By Electro-Brush Plating

Electro-brush plating technology is an effective means in renovateing mechanics. Nano-particle composite electro-brush plating technology combines nano-particle powder with electric brush technology. This kind of method has greatly improved the serviceability of coatings, and has found widely application in coating. The key steps to obtain nano-particle composite electro-brush plating coating are preparing homogeneously scattered composite electrolyte and choosing suitable brushing process parameter. The major results are summarized as follows:1. One of the methods, which disperse the nano-SiC powder among nickel brush-plating electrolyte, is to choose the suitable surfactant by experiments. At first, anionic surfactant, cationic surfactant, non-ionic surfactant and their mixture are used to experimentation of sediment. And according to respective microstructure of nano-particle composite coatings, the built-up systems of cationic+ non-ionic surfactant are selected in which the optimum allocation that can play an important role in dispersing well is cationic surfactant with 0.08g/L and non-ion surfactant with 0.04g/L.2. Surfactant, mechanical and ultrasonic technique are applied together to diverse nano-particle among composite electro-brush plating coating. The result shows that alternatively using mechanical stirring technique and ultrasonic wave shaking are more effectively than only using one kind of scattered method. Based on this method, flat and compact layer of the composite coatings is obtained.3. After using the single factor method to analyze main parameters such as the content of nano-SiC power in composite electrolyte, the working voltage and the temperature of composite electrolyte. The best process parameters of preparing nano-particle composite electro-brush plating coating are gained in the orthogonal test.4. The thickness, hardness, porosity, corrosion resistance and cohesive strength of the composite coatings are measured. The results indicate that the composite coatings prepared by the orthogonal test process show good comprehensive properties performance. Meanwhile, surface microstructure andbroken microstructure are studied through optical microscope and SEM. It is seen that the grain size in composite coatings surface is finer, the coatings boundary is straight and cohesion with matrix is intimate.