Molybdenum Silicide (MoSi,)-based monolithic and composite materials have potential aircraft applications in the temperature range 1000-1600øC. MoSi,-based intermetallics have proven to be rather formidable materials to process because of its extreme brittleness. In order to successfully process and fabricate components based on MoSi,, it is necessary to enhance its low temperature, ductility, and toughness. This research focuses on preparation of fine grained MoSi,, via advanced rapid solidification and powder metallurgical processing to improve its low-temperature ductility and toughness. The fine grain size will reduce the slip length, therefore, lower the stress concentration at the grain boundaries and thus, enhance ductility. Phase I research will also investigate the effect of TiB, and HfC dispersoids on grain refinement. It is expected that these stable dispersoids will retain the fine microstructure as well as aid in dispersing planar slip so that fracture will occur through the formation of voids around these incoherent particles, especially at higher temperatures.The potential commercial application as described by the awardee: Dispersion strengthened MoSi, will find applications as high-temperature, oxidation-resistant structural materials in aerospace industries as well as in nuclear, chemical, and energy conversion/ generation equipment.
