Features of precision casting:

(1) can make complex shape of the blank or parts;

(2) small machining allowance, metal utilization rate;

(3) adaptability, wide application, used for the manufacture of commonly used metal and alloy cast iron;

(4) low cost of casting;

(5) the casting grain is relatively thick, loose structure, often exist air holes, slag inclusion and other casting defects, mechanical properties than forging poor;

6 casting production process, casting quality is not stable, high scrap rate;

7 casting surface is rough, mostly used for the manufacture of blank. The reason of sand inclusion and sand hole in precision casting is that the sand cleaning inside the mold is not clean and there is residual gravel. In the process of pouring, due to the iron liquid erosion of the runner wall sand. Some factories use besmear to brush coating to prevent, took better result, but still can have precision casting to appear clip arenaceous, the case of arenaceous hole.

Because gate besmear brushs coating is more laborious and difficult. Two is in the pouring process pouring temperature high, scour, paint in scour and high temperature immersion is easy to fall off. Cause sand inclusion hole. Many casting plants have not paid much attention to the runner. The erosion of the runner wall during the pouring process is neglected. As a result, the casting sand hole.

The solution to the problem of sand inclusion and sand holes in precision casting is as follows:

1, the use of casting gate ceramic tube, the product is easy to use, with smooth circulation, resistance to molten iron, steel scouring, not absorb molten steel, saws and other characteristics, can simplify the modeling process, save the coating on the inner side of the gate difficult work, and improve the placement of the casting system, avoid sand, sand hole, sand defects. It plays an important role in improving casting quality and casting yield, especially in various self-hardening casting molds.

2. Improve the yield of precision casting, improve casting quality and reduce the total cost of casting.