The cast alloy is not stable and is involved in gas. Correct selection and treatment of cold iron. Improve the design of the gating system. Poor gating system design Prevention method: The type (core) sand is mixed with organic impurities (such as coal cuttings, grassroots horse manure, etc. Improve the exhaust ability of (core) sand. Surface pores and bubbles can be found by sandblasting, and internal pores and bubbles can be found through X-ray fluoroscopy or mechanical processing to find that the pores and bubbles appear black on the X-ray film cause: 1. Poor ventilation of mold and sand core .

There are shrinkage holes on the surface of cold iron . No organic impurities should be mixed into the mold (core) sand to reduce the amount of gas generated by the molding material .Defect characteristics: The pores in the wall of the three castings are generally round or oval, with a smooth surface, usually shiny oxide skin, sometimes oily yellow. Correctly grasp the pouring speed to avoid getting involved in gas.) In order to solve the problem of high scrap rate of automotive aluminum castings and save the aluminum castings that may be scrapped due to the above-mentioned defects, certain treatment measures must be taken in the production.

After these defective castings are machined, the surface dense layer components are removed and the internal structural defects are exposed. Waste products, and these defects are often found only after machining and pressure testing, resulting in serious waste of working hours, raw materials and energy. The so-called 'impregnation' is to infiltrate the infiltrant into the micropores of aluminum castings under certain conditions.In the process of casting aluminum castings, it is easy to produce defects such as internal porosity, shrinkage holes, pores, etc.. For automotive cast aluminum parts with sealing requirements, such as cylinder blocks, cylinder heads, intake manifolds, brake valve bodies, etc.

At present, the most common technology is impregnation treatment, that is, leak plugging. After solidification, the filler that penetrates into the pores is connected to the inner wall of the casting pores to block the micropores so that the parts can Wholesale nonferrous casting parts suppliers be Process technology that meets the conditions of pressurization, seepage prevention and leakage prevention., when conducting pressure sealing tests, the existence of defective micropores will cause a large amount of leakage of the sealing medium                       

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