Formation of nanocrystalline Fe73.5Cu1Nb3Si13.5B9 alloy under high pressure

The formation of nanocrystalline Fe73.5Cu1Nb3Si13.5B9 alloy by annealing an amorphous Fe-73.5 Cu1Nb3Si13.5B9 alloy at a temperature of 823 K under pre ssures in the range of 1-5 GPa is investigated by using X-ray diffraction, electron diffraction, and transmission electron microscopy. The high pressu re experiments are carried out in belt-type pressure apparatus. Experimenta l results show that the initial crystalline phase in these annealed alloys is alpha-Fe solid solution (named alpha-Fe phase below), and high pressure has a great influence on the crystallization process of the alpha-Fe phase. The grain size of the alpha-Fe phase decreases with the increase of pressu re (P). The volume fraction of the alpha-Fe phase increases with increasing the pressure as the pressure is below 2 GPa, and then decreases (P>2 GPa). The mechanism for the effects of the high pressure on the crystallization process of amorphous Fe73.5Cu1Nb3Si13.5B9 alloy is discussed.