Gypsum type rapid precision casting method for nonferrous metal

Abstract

The invention relates to a gypsum type rapid precision casting method for nonferrous metal. The gypsum type rapid precision casting method is characterized by including the steps that a rapid prototype part of a to-be-cast part, a runner rapid prototype part, a riser rapid prototype part and an air channel rapid prototype part are manufactured through a 3D printer and placed in prepared gypsum slurry, and air pipe joint inserts are sleeved with the air channel rapid prototype part; a dried gypsum mold is heated, the rapid prototype part of the part, the runner rapid prototype part, the riser rapid prototype part and the air channel rapid prototype part are burnt out, and then a part cavity, a runner, an air channel and a riser are formed in a gypsum casting mold; the gypsum casting mold is placed in a casting box, the periphery of the gypsum casting mold is filled with dry sand, and a sprue cup is placed in an opening in the upper end of the runner; the gypsum casting mold is fixed through a pressing beam and a rubber pressing block for vibration and compaction, and then the part cavity, the runner, the air channel and the riser are vacuumized; and nonferrous metal casting liquid is poured which vibration is carried out, vibration is stopped after pouring is finished, the gypsum casting mold is taken out, and a needed casting is obtained. The casting quality of the nonferrous metal part can be improved, and the beneficial effects of being easy and convenient to operate and the like are achieved.

Description

technical field [0001] The present invention relates to a non-ferrous metal gypsum type rapid precision casting method, in particular to a non-ferrous metal gypsum type rapid precision casting method with negative pressure and frequency conversion vibration assisted pouring, which is suitable for rapid precision casting of large complex thin-walled parts . Background technique [0002] Gypsum type rapid precision casting technology is a new technology developed in recent years, which is the product of the combination of gypsum type precision casting and rapid prototyping technology. Since the plaster mold does not need parting surface and draft angle, it can cast parts with complex shapes, high dimensional accuracy and surface roughness that are difficult to manufacture by other casting methods, forging, welding, machining, etc. . The combination of rapid prototyping technology and gypsum casting, use FDM, SLS and other rapid prototyping techniques to make plastic, resin o...

AI Technical Summary

Problems solved by technology

[0003] However, there are still some deficiencies in the current gypsum type rapid precision casting technology: (1) The gas permeability of the gypsum mold is poor, and the gas inside the molten metal is difficult to escape, making it difficult to form the casting, and it is easy to produce undercasting (lack of meat), pores, etc., especially It is a thin-walled large flat casting; (2) The thermal conductivity of the gypsum type is poor, and the hot type casting is generally used and the crystallization interval of some alloys is wide, so the crystallization and solidification time of the casting after casting is long, and the casting tends to be loose and shrinkage. (3) When casting large complex thin-walled parts, the cooling speed of the molten metal is fast, so that the viscosity of the molten metal increases, the fluidity deteriorates, and the filling capacity decreases accordingly, which is easy to Various casting defects

[0004] In order to solve the problems of poor gas permeability of gypsum molds and poor filling ability of large and complex thin-walled parts, some people have used the method of applying negative pressure in gypsum mold casting. There are two main methods: (1) Put the gypsum mold in In the vacuum tank (box), directly pour in the vacuum tank (box) after vacuuming; this method requires a special vacuum tank (box), high equipment cost, long vacuuming time, and troublesome operation

(2) Pre-embed steel pipes in the gypsum type for vacuuming; the disadvantage of this method is that the embedded steel pipes are easily blocked by the gypsum slurry when making the gypsum type, and it is difficult or even impossible to clean. In addition, the connection and sealing of the pipes are troublesome

However, in gypsum mold casting, since the vibration applied to the gypsum mold can easily cause the mold to collapse, and it is difficult to fix it on the vibrating table, so few people in gypsum mold casting use vibration to refine the crystal grains. Research a feasible method to make it possible to apply vibration when the plaster mold is poured under the premise of ensuring that the plaster mold does not collapse

Images