Invention Grant
- Patent Title: MnZn-ferrite and its production method
-
Application No.: US15537688Application Date: 2015-12-24
-
Publication No.: US10937579B2Publication Date: 2021-03-02
- Inventor: Norikazu Koyuhara , Yasuharu Miyoshi , Tomoyuki Tada , Satoru Tanaka
- Applicant: HITACHI METALS, LTD.
- Applicant Address: JP Tokyo
- Assignee: HITACHI METALS, LTD.
- Current Assignee: HITACHI METALS, LTD.
- Current Assignee Address: JP Tokyo
- Agency: Sughrue Mion, PLLC
- Priority: JPJP2014-262145 20141225
- International Application: PCT/JP2015/086006 WO 20151224
- International Announcement: WO2016/104593 WO 20160630
- Main IPC: H01F1/34
- IPC: H01F1/34 ; H01F41/02 ; C04B35/626 ; C04B35/64 ; H01F1/36 ; C04B35/26

Abstract:
A method for producing MnZn-ferrite comprising Fe, Mn and Zn as main components, and at least Co, Si and Ca as sub-components, the main components in the MnZn-ferrite comprising 53-56% by mol (as Fe2O3) of Fe, and 3-9% by mol (as ZnO) of Zn, the balance being Mn as MnO, comprising the step of sintering a green body to obtain MnZn-ferrite; the sintering comprising a temperature-elevating step, a high-temperature-keeping step, and a cooling step; the high-temperature-keeping step being conducted at a keeping temperature of higher than 1050° C. and lower than 1150° C. in an atmosphere having an oxygen concentration of 0.4-2% by volume; the oxygen concentration being in a range of 0.001-0.2% by volume during cooling from 900° C. to 400° C. in the cooling step; and the cooling speed between (Tc+70)° C. and 100° C. being 50° C./hour or more, wherein Tc represents a Curie temperature (° C.) calculated from % by mass of Fe2O3 and ZnO.
Public/Granted literature
- US20170352455A1 MnZn-FERRITE AND ITS PRODUCTION METHOD Public/Granted day:2017-12-07
Information query