Studying the effect of plating bath variables on the coating of SiC ceramic particles by nickel electroless plating

Silicon carbide ceramic (SiC) has high hardness, excellent thermal shock resistance, low thermal expansion, high thermal conductivity, and good elastic modulus properties. So, it is used as a reinforcement to metal matrix composites. One of the problems of the industrial application of SiC in the production of composite materials is its non-uniform distribution and poor wettability by the melting of many metals. Among the many methods today to solve this problem is the application of metal coatings such as nickel, copper, and so on by electroless plating on the surface of SiC particles. In this paper, it has been tried to study the effect of plating bath parameters such as pH, plating temperature and time, particle size and powder weight percentage on the coating of SiC particles by electroless nickel plating. Studies have shown that the relative amount of nickel coated is related to the amount of SiC powder in the plating bath, and ۳۰% by volume is the optimal amount of SiC in the bath. As the weight percentage of SiC powder increases, due to the constant concentration of Ni+ ions, the coating becomes non-uniform and some particles will be uncoated. This also occurs in the reduction of SiC particle size. In the study of electroless plating of SiC particles with a particle size of ۱۰ microns using the reducing agent hydrazine and nickel chloride salt, the results showed that SiC powders did not show any weight gain or reaction at pH below ۸, and at pH between ۱۰ and ۱۱, the weight gain of the powders was close to the theoretical density, and Ni peaks appeared relatively strong in the X-ray diffraction patterns. The best conditions for optimal layering and creating a uniform nickel coating on the surface of SiC ceramic powders with dimensions of ۱۵ microns have been created at the bath temperature of ۸۵°C and the pH of ۱۳.

کلیدواژه ها:

Coating of SiC particles ، Ni electroless plating ، pH ، plating time and temperature