Anisotropic injection molding of strontium ferrite powder using a PP/PEG binder system

In this study, new binder system for anisotropic injection molding of Sr-fe rrite was developed and a process for injection molding of Sr-ferrite was o ptimized. The developed binder system is composed of 30 vol% PP, 60 vol% PE G-20 000 and 10 vol% PEG-4000. The extraction by water was applied to remov e the major binder components PEGs and the minor binder component, PP, was subsequently burned out in air. Behaviors of extraction and thermal debindi ng with time and debinding atmosphere and variations of the magnetic proper ties with sintering temperature were studied. The sintered magnets made by PIM process showed residual carbon content of 230 ppm. and a maximum energy product of 4.2 MGOe. (C) 2001 Elsevier Science B.V. All rights reserved.