How to Do the Alkaline Etching for Cast Aluminum Parts?
The cast aluminum parts have variety of compounds between the metal and other inclusions besides free silicon. And because of loose organization of the cast aluminum parts, there is possibly the phenomenon of uneven chemical composition segregation, while the formation of the surface dense oxide film after casting cooling process to cast aluminum parts. Alkaline etching time is so short that the cast aluminum parts may not be completely divisible, and the eclipse cast aluminum base dissolved faster, often after alkaline etching cast aluminum parts which had caused the corrosion, which led to the size tolerance changes, or even result in product obsolescence.
In view of the existence of this situation, operators can change the alkaline etching process to resolve. In other word, after casting forming operators take alkaline etching treatment for the cast aluminum parts. Follow the program process, it would not only prevent from the occurrence of scrap parts caused by alkali corrosion, but also conducive to oxidation of the surface quality.
Take the alkaline etching method can make cast aluminum parts avoid corrosion. After the alkaline etching of cast aluminum parts, operators can use 2 ~ 3s to polish the cast aluminum parts with 1:1 hydrochloric acid. Instead of toxic hydrofluoric acid, the aluminum parts will take both advantages and environmental protections, improvement of working conditions, but also reduction of production costs.