Alkali Corrosion Method For Aluminum Die Castings

Sometimes we find that the surface of aluminum die casting looks rough. There are many factors cause this phenomenon. For example, there are a variety of compounds and other inclusions. Sometimes chemical composition segregation is not uniform. And it not forms dense oxide film after casting cooling. At this time, we will find the alkali corrosion method can play a key role to improve this problem.

However controlling alkaline etching time is difficult, at the same time, it is also a key factor. If the alkaline etching time is short, aluminum die casting may can not be moved throughly. On the contrary, too long time will cause production excessive corrosion. So that the dimension tolerances will be changed. The best method is changing the alkaline etching procedure. In other words, treat the die casting with alkali corrosion method, this will not only improve surface quality, but also prevent many problems which caused by alkali corrosion.

After alkali corrosion treatment, you can also use hydrochloric acid to fast light. This effect will be better. Die casting is one of the most advanced metal forming method. It is an effective way to achieve the goal of little chips and no scraps.

Basic Raw Material For Producing Molds

The basic material for producing molds is foundry sand and sand binder. The most commonly foundry sand is silica sand. When high temperature performance of silica sand cam not meet the using requirement, we usually use the zircon sand, iron ore, corundum sand and other special sand.

In order to make the molds and cores with intensity, people should join the sand binder in the casting and made loose sand bonded. The most widely used sand binder is clay. Certainly you can also make different kinds of water-soluble silicate, phosphate and various kinds of synthetic resin into sand binder. According to different strength way and binder, sand mold which used in sand casting can divided into three types. They are clay wet sand, chemical sclerosis sand and clay dry sand.

The cor made of core sand has wider application. Oil viscosity is low and the mixed core sand always with good fluidity. So it is very easy to be compaction while core making. However the core which just made is in low strength and usually undertake by copying support core plate. Then put it to the oven which has in high temperature for several hours. The disadvantage of this core making method is that the core is easy to deform in the release, handling and baking process. So the precious of casting size has been decreased. This method also should cost long time to baking and many energy consumption.