The influence of protective atmosphere on the oxidation of sintered SmCo_5 magnetic materials

摘要

The possibility of using low and medium vacuum (10~(-3)-10~(-4) bar), as a protective atmosphere, in the sintering and heat treatment of SmCo_5 magnets was explored. The influence of the used protective atmosphere on structural changes in SmCo_5 magnets was investigated, for different temperature and time intervals, but for a constant temperature and time of heat treatment. The presence of oxides, or any other inclusions, was not proved in any part of the sintered SmCo_5 sample, except in the surface layer. The width of the oxide layer was measured by Scanning Electron Microscopy (SEM), using the Texture Analysis System (TAS+). A regression model was established, showing that the width of the oxide layer grows with the square of the sintering temperature, and linearly with sintering time, for defined heat treatment conditions.