| Abstract |
| Beta-type titanium alloys have a low elastic modulus, excellent cold workability, and are widely used as implant materials. High strength is possible by forming a precipitation in the β-matrix via solution treatment and aging treatment. However, beta titanium alloys require a large amount of beta-stabilizing elements (Fe, Nb, Mo, Ta, etc), and these expensive beta stabilizing elements increase the manufacturing cost of these alloys. In this study, Ti-5Mo-2Fe metastable beta-titanium alloy was designed by adding Mo and Fe, which were relatively inexpensive and had excellent biocompatibility among beta-stabilizing elements, and an ingot was manufactured by vacuum arc remelting. Solution treatment was maintained at 850℃ for a holding time of 1 hour, followed by furnace cooling. Aging treatments were conducted in a range of temperature 350~500℃ and holding time 2 h~48 h. The microstructure behaviors and mechanical properties were analyzed according to these aging treatment conditions. Isothermal ω phases were precipitated by aging treatment, and hardness and yield strength were found to be significantly higher for conditions of 400℃, 8h. As holding time and temperature increased, these phases transformed into secondary alpha phases and the hardness and yield strength decreased due to this microstructural evolution.
(Received 8 February, 2023; Accepted 17 May, 2023) |
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| Key Words |
| Metastable beta titanium, aging treatment, ω phase, secondary α phase |
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