Mechanically activated reactive synthesis of refractory molybdenum and tungsten silicides

In this study, processing of elemental powders mixtures was carried out by mechanical alloying (MA) and heat treatment in vacuum at 700–1000 °C for 1 h. The phase transformation of the powders was investigated by X-ray diffractometer (XRD). The results showed that mechanical alloying promoted the formation of a solid solution of elemental powders. The energy stored in the powders was increased as a result of exterior energy and the barrier energy of the formation of the compound could be exceeded easily. Intermetallics of MoSi₂, WSi₂, Mo₅Si₃, Mo₃Si and SiC/MoSi₂ composite powders were synthesized by mechanically activated reactive synthesis (MARS). The mechanically induced self-sustaining reaction was observed in MoSi₂ and MoSi₂ + 10 wt%SiC stoichiometry system. It has concluded that mechanically activated reactive synthesis is an effective method for the preparation of high melting-point refractory compounds.