Wax mold combination of four-connection hollow turbine guide vane and precision casting method of wax mold combination

Abstract

The invention provides a wax mold combination of a four-connection hollow turbine guide vane, which has high product quality and can completely solve the problems that a rotary connection R part of an edge plate and a vane body is hotly cracked and loosened, and a precision casting method of the wax mold combination. The wax mold combination comprises a sprue cup and a straight pouring gate which is communicated with an outlet end of the sprue cup, wherein inner sprue assemblies are arranged on the side wall of the straight pouring gate; each inner sprue assembly comprises a lower edge inner sprue communicated with one side of a vane lower edge plate cavity, and an upper edge inner sprue communicated with one side of a vane upper edge plate cavity; and each lower edge inner sprue and each upper edge inner sprue are sequentially arranged along the flow direction of the straight pouring gate. The precision casting method comprises the following steps: (1) manufacturing the wax mold combination; (2) carrying out shell making on the wax mold combination prepared in the step (1) to obtain a four-connection hollow turbine guide vane shell; and (3) covering one layer of ceramic heat-preservation cotton on a shell vane body part and covering two layers of ceramic cotton on the whole shell; and putting the treated shell into a roasting furnace for carrying out casting.

Description

technical field [0001] The invention relates to the technical field of precision casting, in particular to a wax pattern combination of quadruple hollow turbine guide blades and a precision casting method thereof. Background technique [0002] In the prior art, investment casting without margin is currently the best method for manufacturing turbine blades. Its technological process mainly includes the design and manufacture of core molds, pressed cores, design and manufacture of wax molds, assembly and injection of wax, slurry shell making, drying shells, dewaxing, sintering, pouring metal, shelling and core removal , Laser drilling and other links. The quadruple hollow turbine guide vane adopts the combination scheme of top injection and bottom injection to produce this type of casting, such as figure 1 As shown, the top injection and the bottom injection are used, and a set of two wax patterns are combined; after the wax pattern is made, the entire shell is wrapped with ...

AI Technical Summary

Problems solved by technology

The quadruple hollow turbine guide vane adopts the combination scheme of top injection and bottom injection to produce this type of casting, such as figure 1 As shown, the top injection and the bottom injection are used, and a set of two wax patterns are combined; after the wax pattern is made, the entire shell is wrapped with a layer of ceramic wool. Although this process scheme can reduce the looseness of the casting and reduce the The number of hot cracks, but cannot completely eliminate casting hot cracks and loose defects

At the same time, in the combination of top injection and bottom injection, the problem of thermal cracking at the junction R of the four-connected hollow turbine guide blade and blade body cannot be solved, and the scrap rate is high.

And in the process of slurry coating and shell making, the stress is not uniform, and hot cracking defects are prone to occur

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