Abstract
Mo-Si-B intermetallic alloys have the potential to possess the oxidation resistance and mechanical properties required for the next generation of jet turbine engine blades. In a novel approach, three-phase alloys of α-Mo, Mo3Si (A15), and Mo5SiB2 (T2) have been produced through the reaction of molybdenum, Si3N4, and BN powders. Formation of the intermetallics was examined by thermo-gravimetric and x-ray diffraction analysis. Densities of 94% of theoretical were achieved from pressureless sintering at 1,600°C. Microstructure examination using scanning electron microscopy and electron backscatter diffraction analysis shows that this powder metallurgy approach yields a fine dispersion of intermetallics in a molybdenum matrix with grain sizes on the order of 1–4 µm. The formation of Mo-Si-B alloys from the nitride-based reactions uses standard powder processing methods and provides a method for creating these materials in a much less complex and expensive manner than has been previously demonstrated.
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Middlemas, M.R., Cochran, J.K. Dense, fine-grain Mo-Si-B alloys from nitride-based reactions. JOM 60, 19–24 (2008). https://doi.org/10.1007/s11837-008-0084-1
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DOI: https://doi.org/10.1007/s11837-008-0084-1