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. 15, 1992
Filed:
Mar. 07, 1991
Hitachi Metals, Ltd., Tokyo, JP;
Abstract
A high strength lead frame material consists essentially, by weight, of 0.5 to 22% Co, 22 to 32.5% Ni, not more than 1.0% Mn and not more than 0.5% Si and the balance Fe and incidental impurities. The contents of Ni and Co are selected so that the Ni content is 27 to 32.5% when the Co content is less than 12%, and so that, when the Co content is not less than 12%, the Ni content and the Co content meet the condition of 66%.ltoreq.2Ni+Co.ltoreq.74%. The material has a multi-phase structure formed of austenitic phase, martensitic phase, and ferritic phase, the austenitic phase occupying not less than 50% of the structure. The method of producing the alloy of the invention comprises the steps of solid-solutioning the material of the above composition at a temperature not less than austenitizing completion temperature, cold-rolling the material at a rate of 40 6to 90% in reduction, and annealing the material at a temperature less than the austenitizing completion temperature.