Microstructure characterization of hot isostatic pressed Ti–6Al–4V alloy under uniaxial compression and post heat treatment
| Autor: | Zhaoming Yan, Haijun Liu, Jinsheng Ji, Yong Xue, Beibei Dong, Yusha Shi, Jishi Zhang, Leichen Jia, Jie Zheng |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Acicular
Mining engineering. Metallurgy Materials science Misorientation TN1-997 Metals and Alloys Nucleation Recrystallization Strain rate Microstructure α variants Surfaces Coatings and Films Biomaterials Deformation mechanism Ceramics and Composites Lamellar structure Deformation (engineering) Composite material Trimodal microstructure Thermal deformation & heat treatment |
| Zdroj: | Journal of Materials Research and Technology, Vol 15, Iss, Pp 7070-7084 (2021) |
| ISSN: | 2238-7854 |
| Popis: | The microstructural evolution law and the α variant selection relationship, as well as the deformation mechanism of the HIPed Ti-6Al-4V alloy, were investigated under the conditions of thermal compression and subsequent heat treatment. The results showed that lamellar α phase bending/kinking and fragmentation were the main spheroidizing mechanisms in the α+β phase region (850°C and 920°C), DDRX occurred as the restoration mechanism in the near-β region (940°C), and the heterogeneous microstructure originated from the temperature gradient distribution. The strain rate clearly affected the dynamically recrystallized grain fraction and diameter, e.g... both the fraction and diameter increased at a lower strain rate. The acicular α precipitated from β phase at 940°C obeyed the Burgers relationship with β, and their misorientation angle intensified at approximately 60°. GBα formed by reducing the adjacent lamellar α misorientation angle; therefore, the GBα nucleation energy was lowest. The microhardness variation was relatively stable along the X direction at α+β phase region deformation, while oscillation appeared at near-β deformation, which can be explained by microstructure heterogeneity after thermal compression. For heat treatment, the trimodal microstructure appeared at 940°C/0.001 s-1/60% thermal compression and subsequent 950°C/1 h/WQ heat treatment, and the result might guide practical production to optimize mechanical properties. |
| Databáze: | OpenAIRE |
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