Precision Casting Method of Aluminum Alloy Cylindrical Shell with Holes

Abstract

The invention relates to a precision casting method for an aluminum alloy tubular shell with hole passages. The precision casting method sequentially comprises the following steps that (1) a casting system of the cylindrical shell is manufactured, and copper tubes are embedded in shell convex rib pouring gates; (2) the casting system is fixed on a centrifugal casting device; (3) the casting systemis rotated, aluminum alloy liquid is injected into a pouring cup, the aluminum alloy liquid flows in the radial direction along all cross gates, and then the aluminum alloy liquid is uniformly injected into an inner cavity of the cylindrical shell from all ingates until mold filling is finished; (4) after the aluminum alloy liquid is cooled and formed, an aluminum alloy casting is obtained, the parts above the ingates are removed, and coated sand in inner cavities of all copper tubes is cleaned; (5) the aluminum alloy casting is entirely immersed in a dilute nitric acid solution, and the copper tubes are completely etched to form the hole passages in shell convex ribs; and (6) the aluminum alloy casting is taken out from the dilute nitric acid solution, thoroughly cleaned and dried to obtain a finished product of the aluminum alloy cylindrical shell with the hole passages. The precision casting method has low cost and low consumption of raw materials, the prepared hole passages are smooth and reliable, and the yield is high.

Description

technical field [0001] The invention relates to a precision casting process, in particular to a precision casting method for an aluminum alloy tubular shell with holes, and belongs to the technical field of precision casting. Background technique [0002] When shaping the cylindrical shell, it is necessary to make a wax mold with the same shape as the inner cavity of the shell, then dip the wax mold with the refractory coating, then pour the refractory sand, then dip the slurry, then pour the sand, repeat The inner mold shell is obtained in several layers, and the inner mold shell is dewaxed after being air-dried, and then roasted at a high temperature. After the outer mold shell is made by the same method, the inner mold shell and the outer mold shell are combined into a complete cylindrical shell. [0003] In order to reduce the thickness and weight of the shell and improve the strength of the shell, an annular rib extending in the circumferential direction is often provi...

AI Technical Summary

Problems solved by technology

First of all, it is inconvenient to move. Sometimes the product needs to be transported for a long distance when it is put into the sand shower tank. The labor intensity of the operator is high, and the operation risk is high.

Secondly, the operation is inconvenient. Due to the limited space, during the sand shower operation, the product needs to be turned over, so that the different slurry surfaces face up to receive the sand shower. A little carelessness when turning over can easily break the product or the gating system; even if the operator is very careful , the damage rate is still high, and often needs to be repaired; the operator feels tired, the labor intensity is high, and the product scrap rate is high

[0006] At present, gravity casting is mostly used for small round non-standard parts. Gravity casting injects the molten metal into the hollow mold made of high temperature resistant material at one time, and the product with the expected shape is obtained after condensation. The molten metal is cast during the crystallization process. Insufficient feeding can easily cause shrinkage and porosity

Therefore, risers need to be installed in the thick and large parts of the casting to achieve final solidification, improve the feeding effect of the riser, and cause the metal utilization rate to decrease

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