Abstract
The development of Ti3Al-Nb alloys is an excellent example of the recent resurgence of interest in the use of intermetallics for high-temperature applications. We examine, in this contribution, the structure of a typical alloy Ti-24A1-11Nb and show it to consist primarily of the ordered α2 phase (based on Ti3Al, DO19) and βo, (based on Ti2NbAl, B2) phases, with small amounts of a third phase, which is distorted slightly to an orthorhombic symmetry from the D019 (hexagonal) structure. Tensile properties have been examined on samples heat-treated to vary the size, shape, and volume fraction of α2 phase and the deformation and fracture behavior of the ordered, two-phase mixture established. The tensile ductility is seen to maximize at intermediate volume fractions of the α2 and βo phases (∼30 pct) at values of 6 to 10 pct elongation to fracture, depending on the grain size of the βo phase. A rationale incorporating the failure modes of the two phases—cleavage of α2 and slipband decohesion of βo—has been evolved to explain the trends in ductility with heat treatment.
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.
