Tin is a silver-white metal that is non-toxic and has g […]
Tin is a silver-white metal that is non-toxic and has good weldability and ductility. Widely used in electronics, food, automotive and other industries. The tin plating process of hexagon bolts is classified into two categories: acid plating liquid processing and alkaline tin plating processing.
The advantage of acid tin plating is that the plating speed is fast. The coating is bright and detailed, and the deep plating ability is good. The bath is highly tolerant to impurities and operates at room temperature to save energy. The disadvantage is that the dispersion ability of the plating solution is poor, the porosity of the plating layer is high, the brazing is not as good as the alkaline tin plating, and the divalent tin is hydrolyzed. Due to the different conductive materials, hexagonal bolts are divided into sulphate tin plating, fluoroborate tin plating, and chloride tin plating.
The cost of sulfuric acid tin plating is low, the plating solution is easy to control, the plating layer is bright and delicate, but the dispersing ability is poor. The market is most widely used. The advantage of fluoroborate tin plating is that the plating speed is fast, a large current can be used, and the plating solution has good stability. Widely used for continuous plating of flange nuts, wires and strips. The disadvantage is that the plating solution has high cost, high toxicity and difficulty in treating wastewater.
Tin plating of chloride is mainly tinned in crystal grain, which has the advantages of low cost, stable plating solution and white plating. The disadvantage is that the current is not large. The advantages of alkaline tin plating of hexagon bolts are: simple composition, good dispersion of plating solution, fine coating, less pores and good brazing performance. Disadvantages are: high operating temperature, high energy consumption, narrow current range, low current efficiency, no bright coating, hard plating, and large anode effect.