Molding of slurry-form semi-solidified metal

Abstract

Molding of slurry-form semi-solidified metal, comprising the step of providing a map showing, by metal components, the correlation between solid phase ratio and viscosity with respect to slurry-form semi-solidified metal (27); the step of setting up target viscosity corresponding to target solid phase ratio with the use of the map; the viscosity measuring step of while cooling semi-solidified metal placed in container (13), measuring the viscosity thereof; and the step of continuing cooling until the viscosity reaches the target viscosity, wherein the group of these steps are accomplished between providing of a map showing the correlation between solid phase ratio and viscosity with respect to semi-solidified metal and completion of cooling of the semi-solidified metal to thereby cause the solid phase ratio of the semi-solidified metal to agree with the target solid phase ratio. The viscosity is detected to thereby enable avoiding of the influence of cooling rate variation and time, so that as compared with the conventional supervision on the basis of time, the precision of control of solid phase ratio of semi-solidified metal can be enhanced strikingly.

Description

technical field [0001] The present invention relates to the manufacture of die-cast molded products using paste-like semi-solidified metals such as aluminum alloys. Background technique [0002] The technology of casting molten metal such as aluminum alloy is widely used at present. Recently, die casting using a slurry-like semi-solidified metal in a solid-liquid coexistence state is suitable for improving the life of the die and improving the dimensional accuracy of the die-casting molded product. Law received attention. [0003] In the die casting method using semi-solidified metal, the management of the solid phase ratio indicating the solid-liquid ratio of the alloy melt is very important. In the invention of the management of the solid phase ratio, for example, the method of obtaining the target solid phase ratio is achieved by temperature management to the phase transition point of the semi-solidified metal and time management of stirring from the phase transition poi...

AI Technical Summary

Problems solved by technology

[0048] In order to prevent the breakage of the sand core during casting, it is considered to reduce the injection rate of the semi-solidified metal, but if it takes a long time to inject, the semi-solidified metal will solidify, or the solid phase ratio will change due to the temperature drop, so it may not be possible to obtain the desired result. desired flow properties

In addition, as the temperature decreases, the viscosity of the semi-solidified metal further increases, which may damage the sand core

[0049] In the method described in the above-mentioned Japanese Patent Publication No. 55-19704, although the piston is stopped at the moment when the melt is about to completely fill the volume of the cavity provided with the sand core to suppress the occurrence of impact, when the melt hits the sand core higher speed

If it is a normal melt, it will not be damaged even if it hits the sand core at a high speed, but as mentioned above, in the case of high-speed impact of semi-solidified metal, it may be damaged

In addition, if the injection rate is extremely reduced as in the above-mentioned Japanese Patent Laid-Open No. 9-57415, the injection time will become longer, which is not a problem in the case of a normal melt, but for semi-solidified metals, there will be solidification or flow. problem of reduced sex

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