Method for solving problems caused by hot spots at large-thickness positions of casting through cooperation of chilling coatings and hidden air holes

Abstract

The invention discloses a method for solving the problems of looseness and leakage which are caused by hot spots at large-thickness positions of a casting through cooperation of chilling coatings and hidden air holes. The sand mold surfaces, corresponding to the large-thickness positions, of the product are coated with chilling materials, the hidden air holes are formed in the corresponding sand mold surfaces, the diameter of each hidden air hole ranges from 2 mm to 3 mm, the number of the hidden air holes ranges from 3 to 5, the hidden air holes are evenly distributed on the sand mold surfaces, corresponding to the large-thickness positions, of the product, and the hidden air holes are formed in the sand mold surfaces through cutting, namely, drilling. The method has the advantages that the large-thickness positions of the casting are coated with chilling materials, and therefore the hot spots, caused by wall thickness differences, of the casting are prevented through the hidden air holes formed in the corresponding sand mold surfaces, and no more leakage happens to the casting when air tightness of the casting is detected.

Description

technical field [0001] The invention belongs to the field of low-pressure casting, and in particular relates to a method for solving heat knots at the wall thickness of castings through the combined use of chilling paint and dark air holes. Background technique [0002] Chilled coatings contain Te and Fe 2 o 3 , they have good thermal conductivity for aluminum alloys, so that the molten aluminum can solidify quickly to form a dense surface. [0003] Taking the high-voltage switch breaker tank as an example, the wall thickness of the cylinder body is 10mm, and the local thickness reaches 32mm. During low-pressure casting, there are 4 ingates in the main pipe and the branch pipe. The sand mold at the ingate is severely heated. The sand mold is easy to be heated and the resin in the sand burns to release gas, the gas cannot be discharged from the mold, and it is adsorbed on the surface of the solidified shell, blocking the heat conduction between the aluminum liquid and the m...

AI Technical Summary

Problems solved by technology

[0004] Therefore, it is imperative to develop a method that can avoid the difference in wall thickness of the casting and solve the hot spot at the wall thickness of the casting. After searching relevant documents, no technical solution identical to the present invention has been found.

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