Abstract
For miniaturization and complication of the shape of electronic devices in recent years, improvement of magnetic properties are also being required to the soft magnetic components. Fe-Si-Al alloy is well known to be a soft magnetic material suited for a magnetic head because of high permeability and magnetic flux density as well as high wear-resistance. However, this alloy is very brittle and difficultly workable. Therefore, metal injection molding (MIM) process is hoped to be a suitable production route for hard and brittle materials such as Fe-Si-Al alloy because of providing net shape components.
In this study, the effect of MIM process conditions on the magnetic properties of Fe-Si-Al alloys has been investigated using a gas-atomized powder. Since this alloy melted at high temperature over 1523K, the optimum sintering temperature was found to be 1523K at which the obtained relative density was more than 98%. However, the magnetic properties of the compacts sintered in both hydrogen and vacuum atmospheres were relatively inferior to that of the wrought materials. This was seemed that the domain wall migration was prevented by the fine grain size and the retained oxides. By the continuous process including the debinding and sintering steps together, the compacts showed good magnetic properties because of the small amomts of oxides and coarse grain size.
