Assessment of Processing Routes and Strength of a 3-Phase Molybdenum Boron Silicide (Mo 5Si 3-Mo 5SiB 2-Mo 3Si)

Abstract

High temperature components such as furnace elements are often fabricated from MoSi{sub 2}. Molybdenum boron silicides consisting of Mo{sub 5}Si{sub 3}, Mo{sub 3}Si, and Mo{sub 5}SiB{sub 2} are an interesting alternative to MoSi{sub 2}. At present, the mechanical properties of these new Mo-Si-B intermetallics have not been fully explored. One reason for this is simply the unavailability of sufficiently large parts with a sound microstructure. The goal of this work was therefore to explore the processing of these materials by several different routes such as powder and ingot metallurgy, and examine the resulting microstructures. In addition, some post-processing (hot isostatic forging, extrusion) was carried out. The flexure strength of the differently processed materials was characterized and interpreted in terms of their microstructures.