In addition to aluminum parts containing free silica, as well as a variety of compounds between metals and other inclusions. And because aluminum casting loose tissue, so there could be uneven chemical composition segregation phenomenon, while cooling after casting unprocessed surface oxide film will form dense. Alkaline etching time is short, it may not be completely cast aluminum divisible, and alkali corrosion due to the faster dissolution of aluminum, often resulting rise in aluminum casting is too corrosive alkali corrosion, causing tolerance dimensions change, even cause product obsolescence.

In view of the above circumstances exist that can be taken to change the alkaline etching process to solve, first alkali etching treatment that casting. Click craft program operation can prevent erosion caused by alkali scrapped parts and other problems, but also favorable surface quality after oxidation.

Taking the above alkaline etching method can avoid parts being too corrosion, erosion can also use an alkali: 1 hydrochloric acid fast light 2 ~ 3s, and replace more toxic hydrofluoric acid, both favorable environmental protection, improve working conditions, but also reduce production costs.