Casting method and casting apparatus

Abstract

A casting apparatus has a long cooling jig inclined with respect to a vertical direction. A melt is supplied to and flowed on a bottom surface of the cooling jig, whereby a solid phase is generated in the melt to obtain a semi-solid slurry, and the semi-solid slurry is transferred into and solidified in a cavity of a mold to obtain a casting. The casting apparatus further has a release agent application unit, and a release agent is applied by the application unit to the bottom surface of the cooling jig in a direction toward a supply of the melt at an angle of less than 90° to the bottom surface before supplying the melt to the cooling jig.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application is based upon and claims the benefit of priority from Japanese Patent Applications No. 2010-011751 filed on Jan. 22, 2010, No. 2010-063237 filed on Mar. 18, 2010, No. 2010-063241 filed on Mar. 18, 2010 and No. 2010-063246 filed on Mar. 18, 2010, of which the contents are incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a casting method using a cooling jig for generating a solid phase in a melt flow to prepare a semi-solid slurry and a casting apparatus containing the cooling jig.[0004]2. Description of the Related Art[0005]In common casting, a cavity formed in a mold is filled with a high-temperature liquid-phase melt. Recently, a semi-solid slurry containing both of solid and liquid phases is occasionally used instead of the melt. For example, as described in Japanese Patent Nos. 3920378 and 3339333, the semi-solid slurry can be prepared by f...

AI Technical Summary

Benefits of technology

The present invention provides a casting method and apparatus that can continuously produce high-quality castings with reduced production costs and prevent gas defects. The method involves using a long cooling jig that is inclined and a release agent application unit to easily remove any residual solid from the cooling jig. The cooling jig is designed to prevent heat cracking and can be easily moved to facilitate the continuous casting process. The release agent application unit sprays the release agent onto the cooling jig at an angle of less than 90 degrees to prevent splashing and can be easily removed from the injection sleeve or vessel. The method also involves spraying air onto the lower end of the cooling jig to prevent the release agent from being introduced into the injection sleeve or vessel. The apparatus includes a jig transfer unit for moving the cooling jig and a release agent application unit to apply the release agent to the cooling jig before the melt flows on. The method and apparatus provide a more efficient and cost-effective way to produce high-quality castings.

Problems solved by technology

When another melt for the next casting is flowed on the cooling jig without removing the residual solid, the melt cannot be sufficiently cooled and the solid phase content of the semi-solid slurry cannot be easily increased to a desired level.

Furthermore, when the residual solid is poured together with the melt into the plunger sleeve, it may cause clogging.

In addition, even if the clogging can be avoided, in case the residual solid is transferred together with the melt to the cavity, the quality of the resultant casting is deteriorated.

In a case where the release agent is applied to the cooling jig in this manner, the following problems are generally caused.

In this case, the release agent may be undesirably incorporated into the generated semi-solid metal to increase gas defects in the product.

When the release agent is water-soluble or heat-insulating, the following problems are caused.

Furthermore, the water may be incorporated into the melt and gasified therein, causing a gas defect.

As a result, the quality of the resultant product may be significantly deteriorated.

However, the cooling jig having such a high temperature exhibits a deteriorated melt cooling performance disadvantageously.

When the cooling jig is covered with the generated vapor, the vapor may interfere with the release agent application in the later stage of the continuous application.

However, disadvantageously, the excess release agent may be splashed and introduced into the plunger sleeve placed in the vicinity of the lower end of the cooling jig, and the cooling jig may be excessively cooled by the excess release agent.

Obviously, the application of the excess release agent results in casting cost increase.

This technology has the following disadvantage in the continuous operation.

That is, it is difficult to uniformly apply a powder of the BN or the like to the cooling jig.

When the predetermined thickness is not realized, the desired semi-solid metal cannot be obtained, and the resultant product cannot have excellent quality.

In addition, it is remarkably difficult to control the thickness of the coating per se in the continuous operation.

However, in this case, a complicated apparatus is disadvantageously required.

Further, when the cleaning takes a long time, the cycle time and the casting cost are increased.

Thus, this technology is disadvantageous also in space saving.

As described in Japanese Laid-Open Patent Publication No. 2006-305618, when the heat-insulating release agent is applied to the cooling jig, because the heat transfer between the metal melt and the cooling jig is reduced, the metal melt cooling rate is deteriorated.

Thus, the resultant semi-solid metal has a coarse structure, and the desired solid phase content cannot be achieved.

However, in this case, the cooling jig is readily interacted with the melt, causing erosion.

Also, the residual solid cannot be easily removed from the cooling jig as described above.

However, in this case, it is difficult to remove the residual solid from the cooling jig disadvantageously.

In this case, it is difficult to remove the residual solid due to the aggregate.

Therefore, it is naturally difficult to remove the residual solid.

Therefore, it is difficult to put the rotary shaft and the plural cooling jigs into practical use.

In addition, due to the plural cooling jigs, an equipment containing the casting apparatus has a complicated structure and increased control and regulation items.

Therefore, this method is disadvantageous in that the casting process cannot be continuously repeated with ease.

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