Study On The Process Of Electroless Ni-P Alloy Plating And Ni-P-Carbon Fiber Composite Plating On Spin-rings

Electroless plating is a metal deposit process on the metal surface where the metallic ions are reduced by reducing agent and the self-catalyst of matrix materials. Mechanism of electroless plating process is redox reaction where there is a electrons transfer and no electrical supply in the process. Electroless composite plating is a technology of suface treating based on electroless plating process by adding compound particles with high hardness and wear-resistantance. Composite deposite have all advantages of normal deposite and compound particles. This surface treating technology has wide application in mechanical industry fields, electronical industry fields, textile industry fields and chemical industry fields.The technical process and heat treatment of electroless plating of Ni-P and Ni-P-Carbon fiber(Cf) was studied in this paper. The objective of this research is to improve wear-resistance of Spin-rings by electroless plating of Ni-P and Ni-P-Cf and heat treatment. The concentration of complexing agent, reducing agent and stabilizer were optimized by orthogonal test. The concentration of Cf, stabilizer and stir were also optimized by orthogonal test. The solution stability of two process and their heat treatment were studied systematically. The surface morphology and structure of (compound) plating was studied by SEM and XRD. The results show that:The life-span of Ni-P solution is determined by the concentration and species of complexing agent and stabilizer, and stir method play a key role in electroless Ni-P-Cf composit plating.The as-deposit microstructure of electroless Ni-P plating is amorphous state, and will be transformed to crystalline state after heat treatment while the hardness of plating is improved. The structural feature of electroless composit plating of Ni-P-Cf is a combination of amorphous Ni-P matrix and Cf embedding in the matrix. At this treatment condition, the lower hardness of composite plating is obtained. The connection between Cf and Ni-P matrix is mechanical bonding. But the amorphous Ni-P matrix will be changed to crystalline after certain heat treatment. The composite plating is strengthened because intermetallics Ni3P are precipitated. Meanwhile, the connection between Cf and Ni-P matrix is discovered to change to chemical bonding. The Cf dispersed in matrix layer and composite plating is strengthened again because of this second-phase dispersion. The appropriate heat treatment parameters of Ni-P-Cf...