Phase formation in molybdenum disilicide powders during in-flight induction plasma treatment

In-flight modification of MoSi₂ powders has been carried out by using an Ar–H₂ induction plasma. Reactor pressure, powder feed rate, and plate power level were taken as the experimental parameters to alter the thermal history of the injected powder particles. Metastable hexagonal structure of β–MoSi₂ is the major phase observed in the Ar–H₂ induction plasma-treated molybdenum disilicide powders, while the stable phase of tetragonal structure of α–MoSi₂ usually retains no less than 30 wt. %. Depending on the experimental condition and the deviation from stoichiometry in raw materials, low silicides, Mo₅Si₃ and Mo₃Si, and free Si were observed,