The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Apr. 25, 2000

Filed:

Oct. 22, 1997
Applicant:
Inventors:

Takeyoshi Nakamura, Saitama, JP;

Nobuhiro Saito, Saitama, JP;

Kazuo Kikawa, Saitama, JP;

Takeshi Sugawara, Saitama, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B21D / ;
U.S. Cl.
CPC ...
148549 ; 148550 ; 148438 ; 148439 ; 164900 ;
Abstract

In carrying out of a thixocasting process, a material in a semi-molten state is produced by heating an aluminum alloy material which has a thermal characteristic that a first angled endothermic section generated by the melting of a eutectic crystal and a second angled endothermic section generated by the melting of a component having a melting point higher than an eutectic point exist in a differential calorimetric curve. A start point of a primary pressing stage is established at a point when the temperature T of the material is in a range of T.sub.1 <T.ltoreq.T.sub.4 in the relationship between the temperature T.sub.1 of a rise-start point in the first angled endothermic section and the temperature T.sub.4 of a peak of the second angled endothermic section. At the primary pressing stage, the charging of the material into the cavity in a casting mold is completed. A start point of a secondary pressing stage is established at a point when the temperature T of the material is in a range of T.sub.1 <T.ltoreq.T.sub.3 in the relationship between the temperature T.sub.1 of the rise-start point in the first angled endothermic section and the temperature T.sub.4 of a drop-end point in the first angled endothermic section. At the secondary pressing stage, the material is solidified.


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