Abstract
Directed energy deposition (DED)-built titanium alloys have long suffered from the anisotropic mechanical properties induced by the long columnar prior β grains growing along the building direction, which restricts their applications. In this work, a special interlayer pause (SIP) strategy is designed to reduce the tensile property anisotropy by adjusting the grain morphology. The grain morphologies, microstructure, crystallographic texture, tensile properties and their anisotropy of DEDed TC11 titanium alloys were systematically investigated. The results show that the SIP strategy promotes the columnar-to-equiaxed transition of grain morphology, reduces grain sizes, and weakens the crystallographic textures. The microstructure of SIP samples consists of superfine basketweave and lamellar α laths and residual β phases. The average length of α laths increases with the SIP layer number. In addition, the maintained superfine α phases contribute to an ultrahigh yield strength of ∼1200 MPa of the SIP samples. The yield strength of the horizontal direction gradually decreases and that of the vertical direction increases with increasing the SIP layer number, resulting in a lowered strength anisotropy of less than 2%. When adopting an optimal SIP strategy, the as-deposited TC11 alloy exhibits a relatively small ductility anisotropy.
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.