Transition metal silicides are being considered for future engine turbine components at temperatures up to 1600ºC. Although significant improvement in high temperature strength, room temperature fracture toughness has been realized in the past decade, further improvement in oxidation resistance is needed.

Oxidation mechanism of Ti₅Si₃-based alloys was investigated. Oxidation behavior of Ti₅Si₃-based alloy strongly depends on the atmosphere. Presence of Nitrogen alters the oxidation behavior of Ti₅Si₃ by nucleation and growth of nitride subscale. Ti₅Si₃.2 and Ti₅Si₃C0.5 alloys exhibited an excellent oxidation resistance in nitrogen bearing atmosphere due to limited dissolution of nitrogen and increased Si/Ti activity ratio.

MoSi₂ coating developed by pack cementation to protect Mo-based Mo-Si-B composites was found to be effective up to 1500ºC. Shifting coating composition to T1+T2+Mo₃Si region showed the possibility to extend the coating lifetime above 1500ºC by more than ten times via formation of slow growing Mo₃Si or T2 interlayer without sacrificing the oxidation resistance of the coating.

The phase equilibria in the Nb-rich portion of Nb-B system has been evaluated experimentally using metallographic analysis and differential thermal analyzer (DTA). It was shown that Nb_ss (solid solution) and NbB are the only two primary phases in the 0-40 at.% B composition range, and the eutectic reaction L ↔ Nb_ss + NbB was determined to occur at 2104±5°C by DTA.