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:
Nov. 30, 1999

Filed:

Oct. 09, 1996
Applicant:
Inventors:

Nobuhiro Saito, Saitama, JP;

Haruo Shiina, Saitama, JP;

Takeyoshi Nakamura, Saitama, JP;

Takeshi Sugawara, Saitama, JP;

Kazuo Kikawa, Saitama, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C22C / ;
U.S. Cl.
CPC ...
148440 ; 148437 ; 148688 ; 420544 ; 420542 ; 420528 ; 420548 ;
Abstract

In a thixocasting process, the following steps are used: a step of subjecting, to a heating treatment, an Al-Si based alloy material having a hypo eutectic crystal composition and a characteristic that a first angled endothermic section appearing due to the melting of a eutectic crystal and a second angled endothermic section appearing due to the melting of a component having a melting point higher than a eutectic point exist in a differential calorimetric curve, thereby preparing a semi-molten Al-Si based alloy material having solid and liquid phases coexisting therein; a step of pouring the semi-molten Al-Si based alloy material into a cavity in a casting mold under pressure; and a step of solidifying the semi-molten Al-Si based alloy material under pressure. When the temperature of a rise-start point in the first angled endothermic section is represented by T.sub.1, and the temperature of a drop-end point the first angled endothermic sections is represented by T.sub.2, the casting temperature T for the semi-molten Al-Si based alloy material is set in a range of T.sub.1 .ltoreq.T.ltoreq.T.sub.2. Thus, the fine precipitation of a primary crystal Si phase can be realized to provide an increase in strength of an aluminum alloy cast product.


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