| 摘要 |
The invention relates to foundry engineering. A method of low-pressure vacuum casting includes evacuation of a mold and a furnace chamber, filling the mold with a metal under the action of differential gas pressure between the mold and the furnace chamber, differential pressure adjustment, and subsequent crystallization of casting under pressure equal to the pressure difference in the furnace chamber and pressure in the mold, wherein the mold and furnace chamber are simultaneously evacuated so that vacuum in the mold is higher than in the furnace chamber, and wherein the pressure difference increases according to a given program until completion of the mold filling process, and then a pause is made for formation of solid hard crust on the casting, which is crystallized, and the furnace chamber is connected to atmosphere, and after crystallization of the casting the mold cavity is connected with atmosphere. Due to controlled smooth filling molds with liquid metal, which is carried out under the action of gas pressure differential created under subatmospheric pressure, the quality of castings is significantly improved. |
