|About this Abstract
||Materials Science & Technology 2019
||Ultra High Performance Metallic Systems for Aerospace, Defense, and Automotive Applications
||Development of Nb-Si Based Ultrahigh Temperature Alloys
||Xiping Guo, Song Zhang, Haisheng Guo, Yin Wang, Yanqiang Qiao
|On-Site Speaker (Planned)
Nb-Si based ultrahigh temperature alloys possess higher melting points, relatively lower densities and attractive high temperature strength, therefore, they have been expected to be promising candidate materials employed at ultrahigh temperatures beyond the maximum operating temperature of Ni based superalloys. In this report, the compositional systems, constituent phases and microstructural characteristics of Nb-Si based alloys have been summarized. The alloying effects of Ti, Cr, B, V, Hf, Zr and Al have been revealed. Multi-element alloy systems have been successfully developed towards reaching the balance among room temperature fracture toughness, elevated temperature strength and high temperature oxidation resistance. The integrally directional solidification for this alloy has been realized at melt temperature of 2050℃, and the evolution of directionally solidified microstructures has been illustrated. The room temperature fracture toughness and tensile stress rupture life at 1200℃/70 MPa have been significantly improved by directional solidification.
||Definite: At-meeting proceedings