Dynamic compaction of mechanically alloyed Fe-Si nano powders by magnetic pulsed pressure

Nano Fe-6.5wt%Si powders have been synthesized by mechano-chemical process (MCP) for an application of soft magnetic core. Owing to hard and brittle characteristics of Fe-6.5Si nano powders having large surface area, it is very difficult to reach high density more than 70 % of theoretical density (similar to 7.4 g/cm(3)) by a compaction. To overcome such problems a magnetic pulsed compaction (MPC), which is one of dynamic compaction, was applied. The density of green body was achieved more than 60% by MPC even at R.T., while it was less than 50% by a uniaxial static pressure. When the compaction temperature was 473 K (200 degrees C), 70 % of theoretical density of Fe-6.5Si was obtained without any little grain growth.