One phase ' production method null of Fe4 N super

摘要

PURPOSE: To produce a single phase of γ'=Fe₄N superfine particles without producing and mixing byproducts by using DC arc discharge produced in a mixture gas atmosphere of ammonia and inert gas. ;CONSTITUTION: Ammonia is mixed with argon, helium, etc., to obtain a mixture gas having ≤40 % ammonia concn. as the atmosphere. DC arc discharge is produced in this atmosphere to melt, vaporize and condense pure iron to produce a single phase γ'=Fe₄N superfine particles. In this method, a DC arc plasma generator comprising a vertical cylindrical chamber is used. The mixture gas of ammonia and inert gas is introduced in the tangential direction through a gas inlet port 7 in the upper side of the chamber to produce a swirling gas flow downward. At the same time, arc discharge is performed while the atmosphere gas is injected around the arc discharge electrode 6 through a gas inlet 7' disposed above the electrode for arc discharge. Thus, pure iron 4 is molten and vaporized by arc 3 and made to react with ammonia. The produced single phase γ'=Fe₄N superfine particles are cooled by rapidly passing a cooling part 8 under the arc discharge electrode and collected in a collector 9.;COPYRIGHT: (C)1995,JPO