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

Abstract

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 57vol% 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 1vol% 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.