High temperature oxidation resistant Mo-Si-B alloys and coatings

Abstract

For high temperature application beyond the range of Ni-base superalloys, multiphase Mo-Si-B alloys with compositions that yield the ternary intermetallic Mo5SiB2 (T2) phase as a key microstructure constituent together with the Mo and Mo3Si phases offer an attractive balance of high melting temperature, oxidation resistance and useful mechanical properties. With the (T2) phase as the focal point of microstructure designs, the fundamental basis of alloying behavior has been established in terms of geometric and electronic factors. The microstructure designs provide new directions for processing and new performance levels. Similarly, the systematic investigation of reaction kinetics involving the T2 phase has a direct application to the analysis of oxidation behavior in terms of diffusion pathways and to the design of effective coating systems. From this basis kinetic biasing is used to develop robust multilayered coatings and in-situ diffusion barriers with self-healing and gradient characteristics for enhanced oxidation resistance.

Document Type

Conference Proceeding

Publication Date

12-1-2011

Journal Title

Materials Science and Technology Conference and Exhibition 2011, MS and T'11

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