Improvements in or relating to ferromagnetic bodies of sintered ferrite material
Опубликовано: 15-07-1964
Автор(ы):
Принадлежит: SIEMENS AG, Siemens and Halske AG
Реферат: 964,163. Etching processes. SIEMENS & HALSKE A.G. March 14, 1963 [March 15, 1962], No. 10081/63. Drawings to Specification. Heading B6J. [Also in Division H1] Three examples of etchant are described for removing the surface layer of up to 200 microns of a ferro-magnetic body of sintered ferrite material which improves the magnetic properties of the body (see Division H1). Example 1.-Concentrated phosphoric acid (H 3 PO 4 ) and concentrated sulphuric acid (H 2 SO 4 ) is maintained at 130‹ C. and has an etching time of 1 to 3 hours. Example 2.-Boiling 50% sulphuric acid which has an etching time of 5 to 15 minutes. The above examples produce a rough surface finish but the third example below, produces a smooth surface finish. Example 3.-85% concentrated pure phosphoric acid (H 3 PO 4 ) is maintained at 160- 200‹ C. An etching time of 5 to 15 minutes removes a surface layer of 50-150 microns. The ferromagnetic body is then washed for 30 seconds in 20-50% aqueous-hydrofluoric acid solution, subsequently neutralized by washing with an aqueous ammonia solution and finally rinsed in distilled water. The ferromagnetic body of sintered ferrite material comprises : 52.4 mol. per cent Fe 2 O 3 . 25.4 mol. per cent MnO 22.2 mol. per cent ZnO.
Sintered ferrite material, wire wound component, and producing method of sintered ferrite material
Номер патента: US09434622B2. Автор: Tomoyuki Tada,Yasuharu Miyoshi. Владелец: Hitachi Metals Ltd. Дата публикации: 2016-09-06.