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:
Jun. 13, 2000

Filed:

Jun. 28, 1999
Applicant:
Inventors:

William John Baxter, Bloomfield Hills, MI (US);

Anil Kumar Sachdev, Rochester Hills, MI (US);

Assignee:

General Motors Corporation, Detroit, MI (US);

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C22C / ; C22C / ; C21D / ;
U.S. Cl.
CPC ...
148700 ; 148702 ;
Abstract

An aluminum casting of composition that is hardenable due to the presence of suitable amounts of silicon, magnesium and, optionally, other hardening constituents such as copper, nickel and the like is heat treated for improved tensile strength at 300.degree. C. The casting, which as formed has a microstructure of aluminum rich dendrites, silicon particles and hardening particles, is reheated above 500.degree. C. to redissolve the hardening particles and redistribute hardening constituents through the aluminum dendrites, cooling the casting to 350.degree. C. to 450.degree. C. and holding there to reform an abundance of large stable hardening precipitates in the aluminum dendrites and then air cooling the casting. The thus treated casting may then be artificially age hardened such as by a T5 temper practice.


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