Method of directional solidification based on 3D printing multilayer hollow shell

Abstract

The invention provides a method for achieving directional solidification based on 3D printing of a multi-layer hollow shell mold. The multi-layer hollow shell mold structure serving as a casting moldis suitable for casting a casting through directional solidification due to the excellent cooling capability, but the multi-layer hollow shell mold structure is complex, manufacturing is difficult through a conventional method, and the accurate multi-layer hollow shell mold structure can be manufactured on the basis of printing of the 3D printing technology. When the casting is cast, after liquidmetal is poured into a cavity of the multi-layer hollow shell mold structure, the bottom of the multi-layer hollow shell mold structure is immersed in cooling water to be cooled, directional solidification is formed, along with ascending of the cooling water liquid level, the hollow layer is gradually filled with the cooling water from bottom to top, the liquid metal solidification interface is gradually upwards pushed in the vertical direction under the situation that the height of the liquid metal solidification interface is larger than the cooling water liquid level height, the same heat preservation conditions of various positions of the casting and stable directional solidification are achieved, accordingly, the defects of mixed crystals, spots and the like are reduced, and the purposes that the casting quality and performance are optimized, and the casting qualification rate is increased are achieved.

Description

technical field [0001] The invention relates to the field of casting, in particular to a method for realizing directional solidification based on 3D printing multilayer hollow shell molds. Background technique [0002] Directional solidification is a key technology in the manufacture of aeroengine blades, one of the key technologies in the manufacture of military and national defense equipment, and one of the bottlenecks in my country's manufacturing industry. In typical directional solidification, the ceramic mold shell required for casting castings has thermal radiation to the wall of the holding furnace, which interferes with the heat transfer of the casting along the height direction, affects the temperature gradient in the height direction and the straightness of the solidification interface property, and as the solidification gradually advances, the front of the solidification interface is getting farther and farther away from the water cooling source at the bottom, so...

AI Technical Summary

Problems solved by technology

In typical directional solidification, the ceramic mold shell required for casting castings has thermal radiation to the wall of the holding furnace, which interferes with the heat transfer of the casting along the height direction, affects the temperature gradient in the height direction and the straightness of the solidification interface property, and as the solidification gradually advances, the front of the solidification interface is getting farther and farther away from the water cooling source at the bottom, so the temperature gradient at the front of the solidification interface is getting smaller and smaller, and the cooling rate is getting smaller and smaller, which affects the quality of the casting , it is easy to produce defects such as miscellaneous crystals and freckles, which will reduce the performance of the casting and even make the casting scrap

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