The difference between the crystallization processes induced by mechanical milling and annealing under normal and high pressure in amorphous Fe-N alloy

Abstract

An amorphous Fe-N alloy was prepared by ball milling a mixture of Fe and h-BN. Its crystallization processes induced by mechanical milling (MM) and annealing under normal and high pressure were studied. The crystallization product of the amorphous Fe-N alloy induced by MM and annealing at temperatures between 690 and 800 K under pressures of 3-4 GPa is ε-FexN, while the thermal crystallization product under normal pressure is γ′-Fe4N. The difference between the crystallization products produced by mechanical and thermal crystallization is attributed to the effects of local pressure and local temperature produced by ball collisions.