Abstract

Abstract Integrally directional solidification of an Nb–Ti–Cr–Si based ultrahigh temperature alloy is conducted with the use of special ceramic crucibles. The effect of withdrawal rates on microstructure and room temperature fracture toughness is investigated. The microstructure of arc-melted alloy is composed of primary niobium solid solution (Nbss), Nbss/(Nb,X) 5 Si 3 eutectic and fine Nbss/Cr 2 Nb eutectic colonies, and the directionally solidified microstructure is composed of primary Nbss, Nbss/(Nb,X) 5 Si 3 eutectic cells and fine Nbss/Nb 3 Si/Cr 2 Nb colonies (here X represents Ti and Hf elements). The room temperature fracture toughness decreased with increase in the withdrawing rates. The room temperature fracture toughness of the directional solidification specimen with withdrawing rates 10 and 20 μm/s are higher than the arc-melted counterparts. The effects of withdrawing rates on the microstructure and room temperature fracture toughness are discussed based on the microstructural and compositional characters.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.