Variable-wall-thickness sand mold structure design method for targeted control of casting microstructure and variable-wall-thickness sand mold structure

Abstract

The invention discloses a variable-wall-thickness sand mold structure for targeted control of a casting microstructure and a manufacturing method of the variable-wall-thickness sand mold structure, and belongs to the field of sand mold casting. According to the variable-wall-thickness sand mold structure for targeted control of the casting microstructure and the manufacturing method, an integral sand mold of a variable-wall-thickness structure is designed and manufactured through numerical simulation calculation and a 3DP process, and on the basis that the structure and strength needed by sand mold work are kept, the temperature field during alloy solidification is improved by changing the structure and the wall thickness of an external sand box, so that the cooling speeds of all casting parts are consistent, casting defects are avoided, and the structure uniformity and the quality of the casting are improved; and meanwhile, the external sand box is changed into a shape follow-up design, and the sand box is not of a traditional cubic structure any more, so that the sand mold volume is effectively reduced, crude sand is saved, and the cost is reduced.

Description

technical field [0001] The invention belongs to the field of sand mold casting, and relates to a variable-wall-thickness sand mold structure design method and a variable-wall-thickness sand mold structure for target-controlled casting microstructure. Background technique [0002] Sand casting refers to the manufacturing method of producing castings in sand molds. More than 80% of the products in the foundry industry are completed by sand casting. Compared with other casting methods, sand casting has the advantages of low cost, simple production process, short production cycle, and a wide range of alloys, so it is widely used in castings with complex spatial structures, such as engine blocks and cylinder heads, impellers, blades, Transmission box and valve body, etc. In the traditional sand casting process, it is necessary to prepare the corresponding mold according to the shape of the casting, and then use the mold to prepare the sand core and the upper and lower sand boxes...

AI Technical Summary

Problems solved by technology

However, in the process of casting cooling and solidification, due to the traditional sand casting, the upper and lower sand boxes are of square structure, which inevitably makes the wall thickness of each part of the sand mold uneven, resulting in the heat dissipation of each part of the casting when casting parts with complex structures Inconsistency, these factors make the cooling rate of each part of the casting inconsistent, easy to produce shrinkage porosity, shrinkage cavity and other casting defects in the part of the casting after cooling and solidification, and the microstructure of each part of the casting is uneven, thus affecting the overall performance of the casting

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