Abstract
To better improve the microstructure and enhance comprehensive mechanical properties, aging treatment was applied to the selective laser melted (SLMed) Ti–40Al–9V-0.5Y alloys in this work. The effects of aging and traditional two-step heat treatment (annealing + aging) on the microstructure, phase composition and mechanical properties of Ti–40Al–9V-0.5Y alloys are firstly compared. Then, the mechanism of aging superior to annealing + aging is explored based on the phase evolution and transformation kinetics. Compared with annealing + aging treatment, aging treatment has many advantages: 1) more homogeneous and fine microstructure; 2) a well-balanced phase ratio of α2, γ and B2; 3) better comprehensive mechanical properties (strength and ductility); 4) operational simplicity. The phase transformations of α2→γ and B2→γ are the main reason for the increase of γ phase content and grain refinement during aging and annealing + aging. Due to the complex thermal history and rapid cooling rate (103–108 K/s), the larger lattice stored energy and finer microstructure after SLM will provide greater driving force and more nucleation region for the two phase transformations during subsequent aging. The larger degree of phase transformations contributes to forming more γ-phase and greatly refining the microstructure after aging treatment, thus resulting in better strength and ductility.
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.
