In this study, we systematically investigated the effects of short-time heat treatment on the mechanical properties and fatigue strength of Ti 6Al4V alloy produced by selective laser melting (hereafter SLM material). The short-time heat treatment was composed of the following two heat treatments: the first treatment was short-time solution treatment (ST treatment) in which the SLM material was heated at 11731298 K for 60 s and water-quenched; the second treatment was short-time aging treatment (AG treatment) in which the ST-treated materials were reheated at 823 K for 40 s and air-cooled. Before the heat treatments, the microstructure of the SLM material was composed of the acicular ¡A martensite phase and the metastable ¢ phase. When the ST treatment was conducted at 1173 K and 1223 K lower than the ¢ transformation temperature of Ti6Al4V alloy (1271 K), the ¡A phase was transformed to the stable ¡ phase during heating and the new fine ¡A phase was generated in the metastable ¢ phase by water quenching. These microstructural changes reduced the static strength but increased the ductility. When the ST treatment was carried out at 1298 K higher than the ¢ transformation temperature, the microstructure was almost the same as that of the SLM material and the mechanical properties were not greatly altered. AG treatment of the ST-treated materials induced the precipitation of the small ¡ phase and reduced the volume fraction of the metastable ¢ phase. This treatment improved the static strength but reduced the ductility. The fatigue strength of the SLM material was much lower than that of the wrought material (63%) because the molding defects formed inside caused stress concentration and accelerated the initiation of fatigue cracks. However, the ST treatment at 1298 K and its combination with AG treatment effectively suppressed the initiation of fatigue cracks and markedly improved the fatigue strength to the same level as that of the wrought material. To improve the fatigue strength, the ST treatment at 1298 K was more effective than its combination with AG treatment because the volume fraction of the metastable ¢ phase was higher and the compressive residual stress near the surface was higher.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.