Zinc alloy die casting is easy to blister, which is a problem for many electroplating factories, because it is related to the straight-through rate of electroplating products, and will affect whether die-casting factory customers will continue to choose them. Therefore, it is very urgent to solve this problem. In this article, we will analyze the importance of pre-treatment wax and oil removal process for improving the binding force of zinc alloy coating.
Why is it so difficult to choose a pre-plating process?
Pre-plating treatment is a decisive process to improve the quality of zinc-based die casting plating. However, due to the existence of pores and defects on the surface of zinc alloy die casting substrate, as the amphoteric metal is easy to be corroded, then the plating factory in the choice of plating pre-treatment process, it will be difficult to choose.
In alkaline degreasing solution, the corrosion of aluminum phase in zinc alloy is faster than that of zinc phase, while in acidic oxide film removal (activation) solution, the corrosion of zinc phase in the alloy is faster than that of aluminum phase. If the plating plant does not choose a good pre-treatment de-oiling, de-waxing and activation treatment process, then the surface of zinc alloy die casting is easy to produce uneven corrosion, resulting in two possibilities:
a. Expansion of pores on the original surface
b. Due to uneven surface corrosion, exposing pores below the surface layer
Thinking from the perspective of overall production, if there is no thorough washing at the back, resulting in residual degreasing solution or activation solution in the pores of the zinc alloy die casting, then the subsequent plating will be defective.
Zinc alloy die castings need to be mechanically polished, degreased and waxed, electrolytic degreased and surface activated before plating. Among these processes, the key process is the oil and wax removal process. In order to thoroughly clean the polishing wax on the surface of zinc alloy die-castings, you can use Bigely wax removal powder BC-16, which is a yellowish brown solid powder without phosphate, and can quickly clean the polishing wax on zinc alloy die-castings. If you want to clean the polishing paste and oil, you can use Bigely alloy degreasing powder BC-17.
If you want to learn more about the wax and oil removal process, send a message to us.
