Influence of Internal Stress and Crystal Structure on Whisker Growth from Zinc Plating

In a zinc cyanide system, internal stress, lattice distortion, and carbon content of plating are related to one another. The value of these physical and metallurgical properties of plating decreased with an increase in the M ratio (NaCN/Zn) of the baths, and whiskers did not grow below a particular value (i.e. internal stress: 55 MPa; lattice distortion: 0.25%; carbon content: 0.06%). High concentrations of cyanide in baths contribute to the role of the brightener and accelerate grain refinement and brightening of plating; these concentrations did not increase the internal stress and lattice distortion, which significantly affects the inhibition of whisker growth. The results of this work suggest a framework for zinc whisker growth.