SPS sintering and magnetic properties of Fe-based amorphous/nanocrystalline powder

The influence of SPS sintering temperature on microstructure and magnetic properties of the sintering bulk alloy of melt quenching Fe70Cr8Mo2Si5B15 powders by ball milling and MA Fe73.5Cu1Nb3Si13.5B9 and Fe80Co4Nb7B9 nanocrystalline powders was studied. The results show that (1) under 30MPa/5min conditions, the relative densities of bulk alloys increase with the increase of sintering temperatures. When Fe70Cr8Mo2Si5B15 bulk alloy sintered at 1000 degrees C, its relative density reaches above 99%, and when Fe73.5Cu1Nb3Si13.5B9 and Fe80Co4Nb7B9 bulk alloys sintered at 1050 degrees C, their relative densities reach to 99%; (2) the main phase of sintering bulk alloys is alpha-Fe phase, and a little second phase intermetallic compound. The grain size of a-Fe phase in bulk alloys is in nanometer range, Fe70Cr8Mo2Si5B15 bulk alloy has the finest grain size, its average grain size is about 50nm; (3) with the sintering temperature increasing, the specific saturate magnetization B,, of these bulk alloys increases and coercive force H, decreases, respectively. Fe70Cr8Mo2Si5B15 bulk alloy has the lowest H-c, 4.1kA(.)m(-1).