Abstract
To realize near net-shaping of hard-to-process intermetallics is an often challenging but critical issue to their wider industrial applications. In this work, we report that an intermetallic Ti-22Al-25Nb has been successfully fabricated by selective laser melting (SLM). The as-printed samples show a high room-temperature ultimate tensile strength ~1090 MPa and excellent ductility ~22.7%; both values are higher than most conventionally fabricated Ti-22Al-25Nb intermetallic. We clarify the mechanical performance achieved by detailed microstructure analysis, including dislocation analysis and phase constitution analysis. High-density dislocation networks significantly contribute to the strength and ductility, which are further enhanced by the favorable phase constitution, including the nano-scale O phase precipitates within the disordered β phase and disappearance of the brittle α2 phase in the microstructure. Phase evolution during SLM has also been clarified using in situ heating, high-temperature synchrotron X-ray diffraction and Scheil simulation, particularly regarding the O phase's formation. It is demonstrated that O phase is formed by shearing primary cubic B2 phase along (110)[111] direction into an orthorhombic structure under high residual stress. Furthermore, a demonstrative part of turbine blade has been fabricated to highlight the importance of SLM in fabricating critical structural part like the hard-to-process intermetallics.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
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.