On the Microstructure and Properties of the Nb-23Ti-5Si-5Al-5Hf-5V-2Cr-2Sn (at.%) Silicide-Based Alloy—RM(Nb)IC

The microstructure, isothermal oxidation, and hardness of the Nb-23Ti-5Si-5Al-5Hf-5V-2Cr-2Sn alloy Young’s moduli elasticity its Nbss Nb5Si3 were studied. was selected using niobium intermetallic composite elaboration (NICE) design methodology. There macrosegregation Ti Si in cast alloy. Nbss, ?Nb5Si3, ?Nb5Si3, HfO2 phases present as-cast or heat-treated plus TiN near-the-surface areas latter. vol.% about 80%. Ti- Ti-and-Hf-rich solid solution 5-3 silicide, respectively, there a lamellar microstructure these two phases. V partitioned to where solubilities Al, Cr, Hf, increased with increasing concentration. At 700, 800, 900 °C, did not suffer from catastrophic pest oxidation; it followed parabolic oxidation kinetics former temperatures linear latter, mass change lowest compared other Sn-containing alloys. An Sn-rich layer formed interface between scale substrate, which consisted Nb3Sn Nb6Sn5 compounds at °C. latter compound contaminated oxygen. Both oxygen, more severely than bulk also alloying Sn elastic modulus Sn-free solutions. alloy, specific room temperature strength favourably many refractory metal-complex-concentrated alloys (RCCAs). agreement predictions NICE experimental results satisfactory.