Synthesis of Mo-Si-B intermetallic compounds with continuous α-Mo matrix by pulverization of ingot and hydrogen reduction of MoO₃ powders

The fabrication of the intermetallic phase T2-Mo₃Si with continuous matrix of α-Mo was attempted with the combination process of high energy ball milling, pulverization of arc-melted ingot, addition of Mo by hydrogen reduction of MoO₃ and spark plasma sintering processes. High energy ball milling or arc melting of Mo-16.7Si-16.7B (at %) powders were performed to obtain to intermetallic phase T2 and Mo₃Si. The Mo phase of 57 vol% distributed intermetallic compound powders were prepared by hydrogen reduction of MoO₃ and further mixing of elemental Mo powders. X-ray diffractometry analysis revealed that the intermetallic phase T2-Mo₃Si can be produced by the pulverization process of arc-melted ingot. Hydrogen reduction of 1 vol% MoO₃ mixed intermetallic powder followed by further addition of Mo powders was a more adequate method enabling the homogeneous distribution of the Mo phase than that of added MoO₃ powders with total amount. The powder mixture was successfully consolidated by spark plasma sintering yielding a sound microstructure comprising the intermetallic phase T2-Mo₃Si uniformly distributed in a continuous matrix of α-Mo.