Functional Separation and Application of Electroless Nickel Plating

The electroless nickel plating has greatly been advanced as a functional plating technology and as seen in a bar graph that shows consumption (tons/year) from 1985 to 1995 shows that total plating has been increased by 60%, while electroless plating has jumped by 2.8 times, and currently it covers 30% of total plating. In this report the Ni-P electroless plating and Ni-B plating are discussed as well as three-element type of plating's recent applications and classification based on functional point of view. The chemical formulas that describe electroplating are provided for the above mentioned combinations. There is an intimate correlation between amount of phosphorous and the characteristics of the Ni-P plating. This amount does change due to determining factors of pH, nickel salt phosphite salt mole ratio, and the age of the plating solution. A hardness of 500-600 Hv is obtained from such plating and through heat treatment, and hardness increases with recrystallization at 300-400 deg C, reaching a maximum at 400 deg C. Among many graphs are the correlation of post-treatment hardness and temperature for various phosphorous contents as well as that vs. plating conditions such as precipitation rate.