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.
Patent No.:
Date of Patent:
Sep. 25, 2012
Filed:
Dec. 10, 2008
Akira Hibino, Tokyo, JP;
Koji Ichitani, Tokyo, JP;
Akira Hibino, Tokyo, JP;
Koji Ichitani, Tokyo, JP;
Furukawa-Sky Aluminum Corp., Tokyo, JP;
Abstract
An Al—Mg—Si based aluminum alloy sheet having undergone normal-temperature aging (or being in a underaged state) after a solution treatment thereof is, before press forming, subjected to a heating treatment (partial reversion heating treatment) in which the alloy sheet is partially heated to a temperature in the range of 150 to 350° C. for a time of not more than 5 minutes so that the difference in strength (difference in 0.2% proof stress) between the heated part and the non-heated part will be not less than 10 MPa. The alloy sheet thus treated is subjected to cold press forming in the condition where the heated part with low strength is put in contact with a wrinkle holding-down appliance of the press and the non-heated part with high strength is put in contact with the shoulder part (radius) of the punch. In the partial reversion heating treatment, the temperature rise rate and the cooling rate in cooling down to 100° C. or below are set to be not less than 30° C./min. Further, the period for which the alloy sheet is left to stand at normal temperature after the partial reversion heating treatment until the cold press forming is set to be within 30 days.