Browse Prior Art Database

Finishing of Magnetic Ferrite

IP.com Disclosure Number: IPCOM000039928D
Original Publication Date: 1987-Aug-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Bhushan, B: AUTHOR [+3]

Abstract

A residual elastic compressive stress is created on the surface of ferrite after a grinding operation. Further refinement by lapping raises the residual stress, level if any. The residual stress alters the magnetic properties of the ferrite and causes signal distortion when the ferrite is used in magnetic heads. Using a hot phosphoric acid during the lapping process reduces the residual stress. The ferrite blocks used as magnetic head pieces are lapped in a bath of hot phosphoric acid. The ferrite block is simultaneously chemically etched and mechanically lapped. Etching does not increase the residual stress as does mechanical lapping. By simultaneously etching and lapping, the specific lapping energy is reduced which results in the reduction of the residual compressive stress level.

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Finishing of Magnetic Ferrite

A residual elastic compressive stress is created on the surface of ferrite after a grinding operation. Further refinement by lapping raises the residual stress, level if any. The residual stress alters the magnetic properties of the ferrite and causes signal distortion when the ferrite is used in magnetic heads. Using a hot phosphoric acid during the lapping process reduces the residual stress. The ferrite blocks used as magnetic head pieces are lapped in a bath of hot phosphoric acid. The ferrite block is simultaneously chemically etched and mechanically lapped. Etching does not increase the residual stress as does mechanical lapping. By simultaneously etching and lapping, the specific lapping energy is reduced which results in the reduction of the residual compressive stress level.

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