THE FORMATION OF TERNARY COMPOUND FE3MO3C BY BALL-MILLING

Ball milling of Mo in nitrogen and ammonia gases has been studied. Aft er heating, the formation of an intriguing ternary compound, Fe3Mo3C1- x, was observed as a result of Fe (and C) contamination from the milli ng apparatus. For a comparison, mechanical alloying of Fe-Mo-C powders with a stoichiometric composition of Fe3Mo3C was also performed and a gain an Fe-Mo-C alloy was obtained after milling. Thermal analysis sho ws a single transition peak for the formation of both the Fe3Mo3C phas e in the latter case and also for Fe3Mo3C1-x formed as a result of con tamination from the mill. The lattice parameter for the Fe3Mo3C1-x pha se obtained by Mo-gas reaction is smaller than for the Fe,Mo,C phase o btained by mechanical alloying of stoichiometric Fe-Mo-C powders. It i s suggested that, in the Fe3Mo3C1-x phase produced by milling of Mo in gases, a high concentration of C vacancies exists. (C) 1995 American Institute of Physics.