A compound casting method

Abstract

The invention relates to a composite casting method. The composite casting method comprises a moulding method and mould assembling method. The moulding method comprises the following steps: manufacturing various mould cores according to requirements and technological requirements; utilizing an upper mould housing and a lower mould housing which are provided with air holes, pouring gates and feed heads and correspond to a casting in shape by using self-hardening sand; assembling the mould cores into the upper mould housing and the lower mould housing after moulding; and integrally buckling the upper mould housing and the lower mould housing to from a sand mould of which the integral configuration corresponds to the casting configuration. The assembling method comprises the step of embedding the assembled sand mould into a sand box by stones with large enough particles. The composite casting method overcomes the defects existing in an existing casting method, and has the advantages of small using amount of the self-hardening sand, high breathability of the mould, high finished product yield of the casting, high casting production efficiency, recyclable casting materials and the like, and the working environment of a casting shop is also improved.

Description

technical field [0001] The invention relates to the field of metal material casting, in particular to a precision casting method. Background technique [0002] The existing commonly used casting methods include sand casting, metal casting, lost foam casting, pressure casting and centrifugal casting. [0003] Lost foam casting is to paint the surface of the foam mold similar in size and shape to the casting with refractory paint and dry it, then bury it in dry quartz sand for vibration molding, and pour it under negative pressure to vaporize the foam mold, and the liquid metal occupies the position of the foam mold , a new casting method that forms a casting after solidification and cooling. Lost foam casting has the following disadvantages: due to the low strength of the foam mold and its high sensitivity to temperature, the foam mold is easily deformed due to external force, vibration and vacuum during the molding process, which eventually leads to casting deformation; the...

AI Technical Summary

Problems solved by technology

Lost foam casting has the following disadvantages: due to the low strength of the foam mold and its high sensitivity to temperature, the foam mold is easily deformed due to external force, vibration and vacuum during the molding process, which eventually leads to casting deformation; the foam mold is coated with The coating is uneven, or a sand filling blind area is formed when the box is buried, the compactness of the molding sand in the blind area is low, the coating layer is easily damaged, and there will be casting defects such as sand sticking and sand inclusion during casting; After entering the sand box, the foam mold is carbonized, burned, and gasified under the high temperature of molten iron. The sand box that has been vibrated and tightened has poor air permeability, so that the gasified gas cannot be removed cleanly, which will cause many pores in the casting and foam The gas generated by the decomposition is not environmentally friendly; the free carbon generated by the foam mold at high temperature will be enriched inside the casting or on the surface of the casting to form carbon deposits, which will increase the carbon content in the casting and cause carbonation, which will reduce the mechanical properties of the casting. fall and scrap

Metal mold casting has the following disadvantages: the raw material is heat-resistant alloy steel, which is expensive, which makes the casting cost high; the metal casting mold is airtight and has no concession, which is easy to cause defects such as insufficient pouring, cracking or white castings of castings; metal casting mold processing Complex and harsh casting conditions make the casting process complicated

The disadvantages of sand casting are: a large amount of molding sand and core sand are used in casting, and the core is made of quartz sand, fly ash, bentonite, resin binder, etc., which requires manual modeling, which makes labor intensive and takes up manpower There are many, and the environmental pollution is serious, and the workshop environment is very poor; each sandy mold can only be used once, which makes the production efficiency low; the resulting castings have poor dimensional precision, and are prone to wrong boxes, sand holes, rough surfaces, etc., which in turn affect the quality of castings ; The mold has poor air permeability, the castings are prone to pores and uneven pouring, and the yield is low

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