Abstract
In this paper, six alloys with different Co contents (Nb-16Si-20Ti-4Cr-1.5Al-4Hf-4Zr-1Ta-xCo (x = 0, 1, 2, 3, 4 and 5)) were prepared by copper water-cooled crucible arc-melting. The effects of Co on phase selection, microstructure, room-temperature fracture toughness, and compressibility were investigated. The six alloys are composed of Nbss, α-(Nb,X)5Si3, γ-(Nb,X)5Si3, and Cr2(Nb,X) phases. The addition of Co element promotes the precipitation of Tiss phase. Primary β-(Nb,X)5Si3 phase was stabilized at room temperature by adding more than 3% Co. Alloy changes from a near-eutectic to a hypereutectic by the addition of Co. The bulk of primary silicide phase deteriorates the room-temperature fracture toughness. At the same time, Co element solid solution in Nbss phase reduces the Si content in Nbss phase and increases the KQ value of alloy. Therefore, the KQ value of 1Co alloy reaches 13.14 MPa·m1/2. The maximum compressive strength of 5Co alloy is 2155 MPa, which is mainly due to the solid solution strengthening of Co element and the highest silicide phase content.
Sign-in/Register to access full text options 
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 callDisclaimer: 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.
