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:
Mar. 08, 1988
Filed:
Jan. 27, 1987
John E Allison, Plymouth, MI (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
A method is disclosed for making a dual microstructure titanium based engine valve, wherein a first zone of the valve contains essentially a mixture of fine, equiaxed alpha and transformed beta crystalline grains which exhibit high tensile strength and high fatigue resistance, and a second zone of the valve which contains essentially a colony type microstructure exhibiting resistance to high temperature creep. The method comprises: (a) preparing a valve stock of forgeable mixed phase alpha/beta titanium based material; (b) hot working said first zone at a temperature below the beta transus temperature, (c) forging said second zone and, either simultaneously with said forging or subsequent thereto, heat treating said second zone at a temperature above (e.g., 25.degree.-200.degree. F. above) the beta transus temperature for a period of time to achieve beta processing followed by cooling to 1400.degree. F. at a rate of 0.1.degree.-10.0.degree. F./second; and (d) heat treating, immediately subsequent to either step (b) or step (c), at least the first zone at a temperature below the beta transus temperature (e.g., 25.degree.-200.degree. F. below) for a period of time to achieve alpha/beta processing.