How to form hole defects in the casting process of copper castings and how to deal with them
Pore defects in copper castings formed by gas. The surface is generally smooth, mainly pear-shaped, round and oval. Generally, the cloth is exposed on the surface of the casting. Large holes often exist in isolation, while small holes appear in groups.
The general term for the hole defects of different sizes and shapes that occur on the surface and inside of the casting. Including pores, shrinkage holes, shrinkage porosity, etc.
1. Pore defects formed by gas in pore copper castings. The surface is generally smooth, mainly pear-shaped, round and oval. Generally, the cloth is exposed on the surface of the casting. Large holes often exist in isolation, while small holes appear in groups.
2. Porosity casting defects formed by the combination of dispersive pores, shrinkage cavities and shrinkage porosity.
3. Pinholes are generally precipitating pores with the size of the pinhead distributed on the section of the copper casting. Great harm to casting performance.
4. Surface pores are distributed in clusters on the surface of the casting. Its characteristics and causes are the same as the subcutaneous pores, which are usually exposed on the surface of the casting and can be removed after machining 1~2mm.
5. Subcutaneous pores are dispersive pores located under the surface of the casting. It is the reactive pores produced by the reaction between the molten metal and the sand mold. It is usually found after machining or heat treatment.
6. A large amount of gas generated during the pouring process of the choking fire cannot be smoothly discharged, and boiling occurs in the liquid metal, which leads to a large number of pores in the copper casting, and even the defect of incomplete casting.