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:
Feb. 20, 2001
Filed:
Aug. 12, 1999
Patrick Lyle Martin, Auburn, WA (US);
The Boenig Company, Seattle, WA (US);
Abstract
A process for treating an alpha-beta titanium alloy to improve cryogenic notch tensile ratio comprises heating the alloy to near or above its beta transus temperature for a sufficient time to dissolve substantially all alpha grains and thus transform the alloy to the beta form, rapidly cooling the alloy from this temperature to induce a martensitic transformation and produce a fine platelet microstructure, isothermally forging the alloy about 50 to 80 percent at about 300° C. below the beta transus temperature to attain a fine equiaxed microstructure such that the largest microstructural unit is about 2-5 &mgr;m, and then aging the alloy at a temperature about 25° C. to 75° C. below the beta transus to grow the refined equiaxed microstructure such that the largest microstructural unit is about 5-10 &mgr;m. A titanium alpha-beta alloy having enhanced notch toughness comprises titanium, aluminum, and vanadium and is characterized by a microstructure having equiaxed alpha grains whose volume fraction is about 75 to 85 percent, a maximum grain size of the microstructure not exceeding about 10 &mgr;m, and with the volume fraction of primary alpha grains not exceeding about 2 percent.