Why do aluminum die castings have black spots when they are polished? There are several reasons for this.

1. There may be the formation of silicon oxide, or aluminum oxide. The solution is simple, use fresh aluminum ingots.

2. From the release agent. It could be that we sprayed too much release agent.

3. The organic content of the release agent is too high.

At the temperature of hot-melting aluminum, some of these organic substances are reduced to carbon elements, and some of them become organic macromolecular polymers. These mixtures of carbon molecules and polymers, when the aluminum casting is formed, are contained in the surface layer and become the dark spots we see. We can reduce the concentration of the spray, switch to another spray, or extend the blow time after spraying. In order to reduce the formation of carbon elements and prevent the accumulation of macromolecular polymers. With the wide application of plastic products, such as daily chemical products and beverage packaging containers, the needs of appearance often require the surface of the plastic mold cavity to achieve mirror polishing Degree. The production of optical lenses, CDs and other molds have extremely high requirements on surface roughness, so the requirements on polishing are also extremely high. Polishing not only increases the beauty of the workpiece, but also improves the corrosion resistance and wear resistance of the material surface. It can also make the mold have other advantages, such as making the plastic products easier to demould and reducing the production injection cycle.

Located in Ningbo, China, Ningbo Beilun Sandexing Mould Co.,Ltd is professional China High Pressure Die Casting Manufacturers and Precious Die Casting Factory, which offers complete die casting solution for our customers mainly in Aluminum alloy from design to finished product on the basis of our high efficient die casting work team.