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:
Jan. 09, 1990
Filed:
Aug. 01, 1985
Ralph W Scheidecker, Byron, MN (US);
Robert R Suchomel, Byron, MN (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
Process of calcining the ball milling manganese zinc MnZn, ferrite material for achieving a ferrite having a ferrous iron content appropriate for optimum magnetic properties. A first initial ball milling step is very carefully controlled as a small amount of metallic iron is blended into an initial mixture which is a catalyst for the ferrous iron reduction reaction during a calcine step. This provides for a predetermined ferrous iron content to be set in the powder prior to any forming or firing steps. The process includes a controlled atmosphere, time, and temperature for the calcining process step, and a second controlled ball milling step over time where the interaction of the stainless steel balls and milled slurry contributes to final ferrous iron content. These two process steps are balanced yielding a MnZn ferrite powder of a predetermined particle size with a controlled ferrous iron content which is a function of both the calcining and ball milling steps.