Die casting surface treatment process Ordinary polishin […]
Die casting surface treatment process Ordinary polishing wheel and sanding wheel used to deal with the rough surface of magnesium alloy castings, local cracks and other surface defects. The abrasive is corundum or silicon carbide with a particle size of 60 to 320 mesh. The particle size of the abrasive used is determined by the roughness of the original surface and the final surface requirements. Polished magnesium alloy abrasives can not contain iron or other metal particles, as these metal particles, once embedded in the magnesium alloy surface, may cause localized corrosion during the part storage period or pitting during pickling prior to chemical treatment or plating. Casting in the grinding before the conduct of a full clean-up.
Small polishing wheel for complex parts outline, complex parts for the fixed wheel or cloth wheel coated with non-fat compounds for polishing. Abrasive before grinding used abrasive particle size is generally 220 ~ 320 mesh. Magnesium alloy also use fabric polishing or flexible wheel polishing. This polishing is the degreasing compound coated cloth wheel surface polishing. Cloth wheels made of corundum and silicon compounds as abrasive can be smoothed and polished using a magnesium alloy. For color polishing, dry lime can also be used. Abrasive paste is also not allowed to contain iron and other heavy metal impurities.
Magnesium alloy die casting surface treatment is very important. However, no matter what kind of treatment must be taken into account, the magnesium alloy die casting the most dense surface, the most corrosion-resistant. Therefore, it is best not to pretreat all the original epidermis clean, so easily lead to corrosion resistance decreased. General high-purity die casting magnesium alloy corrosion resistance, without treatment.
Industrial grade die cast magnesium alloy composites with other materials or contact with other metals, will produce electrochemical corrosion, the need for surface treatment. Die casting surface treatment processes, the use of polishing, blasting sand, wire brush, file, roller grinding and other mechanical methods to remove burrs, oxides, lubricants, mold release agents, mold sand and other foreign matter. Magnesium alloy die casting is usually to get rid of residual lubricant and other surface contamination, the use of wet drums, or vibrating barrel, the combination of grinding and degreasing surface treatment. This treatment not only completed the cleaning can also make the surface smooth parts. More importantly, the continuous flow of the way to control and clear the deposition of impurities in the surface.