Structural evaluation of Mo–Si–B multiphase alloy during mechanical alloying and heat treatment

Abstract

In this study, an attempt has been made to synthesis Mo–Si–B multiphase alloy powder using a combination of mechanical alloying (MA) and various heat treatments. For this purpose, Mo–14Si–10B (at.-%) elemental powders and pure Mo powder were separately milled using an attritor mill. Mechanically alloyed (MAed) powders were annealed in an atmosphere controlled furnace under constant temperature with different holding times. Metallurgical characteristics of MAed and/or annealed powders were evaluated by SEM, optical microscopy, X-ray diffraction and atomic absorption spectroscopy. The lattice parameter of Mo and Mo alloy were estimated using Nelson-Riley function. The results did not show any solid solution of α-Mo or formation of any related intermetallics after MA. However, α-MoSi₂ and small amounts of Mo₅Si₃ were identified when the MA powders were subjected to high temperature annealing over 10 h. Also, no intermetallic compounds could be identified when powders without MA, were subjected to annealing treatment.