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:
Apr. 11, 2000
Filed:
Apr. 07, 1998
Manabu Nakai, Kobe, JP;
Takehiko Eto, Kobe, JP;
Kabushiki Kaisha Kobe Seiko Sho, Kobe, JP;
Abstract
A heat treatable 7000 series aluminum alloy has a micro-structure with a crystal grain size of 45 .mu.m or less and an aspect ratio (longitudinal/long transverse ratio of crystal grain) of preferably 4 or less, whereby its corrosion resistance is improved outstandingly by applying a solution heat treatment and hardening and subsequently, applying an aging treatment at 100 to 145.degree. C. for 5 to 50 hr, a reversion treatment at 140 to 195.degree. C. for 0.5 to 30 hr. and a re-aging treatment at 100 to 145.degree. C. for 5 to 50 hr. to thereby make an electroconductivity to 38-40 IACS %, and render the micro-structure so as to have a minimum distance for the .eta. phase on the crystal grain boundary of 20 nm or more and a maximum size for the .eta.' phase in the crystal grain of 20 nm or less.