Gating system and pouring method for high-temperature alloy directional solidification forming

Abstract

The invention relates to high-temperature alloy directional solidification, in particular to a gating system and a pouring method for high-temperature alloy directional solidification forming. Gating structures are arranged on the upper portion of a heat preservation heater and in the heat preservation heater and comprise pouring opening blocking plates, pouring funnels, and corundum connecting cylinders between the funnels and die shell pouring openings. During mounting, the pouring opening blocking plates which can move up and down and rotate left and right are arranged above the pouring funnels, meanwhile, layers of high-temperature-resisting materials with the thickness of 0.5 cm-2 cm are stuck on the lower surfaces of the pouring opening blocking plates, and opening ends of the pouring funnels are lower than or flush with upper cover of the heat preservation heater. High-temperature-resisting gaskets are arranged on the contacting faces of the outer surfaces of the pouring funnels and the upper cover of the heat preservation heater in a cushion mode. The corundum connecting cylinders with proper sizes are arranged between the pouring funnels and the die shell pouring openings in a sleeved mode. According to the gating system, metal liquid can enter stably for casting, turbulence and flushing on casting are avoided, slag, other impurities and the like are prevented from entering a cavity, the structure is simple, and investment and production cost are greatly lowered.

Description

technical field [0001] The invention relates to the directional solidification of a superalloy, in particular to a casting system and a casting method for directional solidification of a high temperature alloy. Background technique [0002] Directional solidification technology is not only an important means to study solidification theory, but also an important industrial method to develop new materials; directional solidification technology was first used on aeroengine turbine blades, which greatly improved the performance of the engine; using directional solidification technology, it can Obtain columnar crystal or single crystal structure, improve the longitudinal mechanical properties of the material. Melting the material at high temperature and then injecting it into the cavity is an essential step in the directional solidification process. A search of published patents found that no better casting system has been invented for the casting of superalloys in directional s...

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Problems solved by technology

A search of published patents found that no better casting system has been invented for the casting of superalloys in directional solidification technology. The body solidifies along the direction opposite to the heat flow, and finally a single crystal with a specific orientation is obtained. However, during the casting process, the speed at which the molten metal fills the mold and the time required to fill the mold must be controlled so that the molten metal enters the mold smoothly. Mold, avoid turbulence and flushing of the mold, prevent slag and other inclusions from entering the cavity, especially key parts such as turbine blades, which are very sensitive to non-metallic defects, so. In directional solidification casting, various measures must be taken to prevent inclusions from being mixed into the casting system; in addition, in the traditional casting system, the pouring funnel is placed outside the holding furnace, and the superalloy melt is poured into the funnel without sufficient preheating. On the other hand, due to the huge temperature difference, it is easy to make the pouring funnel burst. On the other hand, considering the solidification structure, when the superalloy melt contacts the non-insulated funnel during pouring, it will inevitably drop sharply and nucleate, thereby improving Nucleation rate, but in order to obtain directional solidification structure or single crystal, it is necessary to suppress the formation of crystal nuclei, which creates unfavorable factors for the subsequent directional solidification. Although a lot of research has been done on the improvement of the casting process, it has not been able to be used in production so far. use

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