Diffusion of nitrogen in solid titanium at elevated temperature and the influence on the microstructure
| Autor: | Jun Ou, Steve Cockcroft, A. Akhtar, Yossi Marciano, Jixiang Xu, Daan M. Maijer, Chris D. Lane |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
Nitrogen Diffusion Analytical chemistry chemistry.chemical_element 02 engineering and technology Nitride 01 natural sciences EDS Biomaterials Phase (matter) 0103 physical sciences Phase diagram Titanium 010302 applied physics Mining engineering. Metallurgy TN1-997 Metals and Alloys 021001 nanoscience & nanotechnology Microstructure X-ray diffraction Surfaces Coatings and Films chemistry Microhardness Ceramics and Composites 0210 nano-technology Nitriding |
| Zdroj: | Journal of Materials Research and Technology, Vol 12, Iss, Pp 125-137 (2021) |
| ISSN: | 2238-7854 |
| DOI: | 10.1016/j.jmrt.2021.02.073 |
| Popis: | Nitrogen introduction to solid commercially pure titanium has been carried out at 1650 °C in an electric induction furnace using two different methods. An effective way to avoid the formation of the hard and brittle nitride layer (TiN and Ti2N) is reported. Microstructure and microhardness were examined on the cross-section of the nitrided samples. Multiple phase layers can be observed, and the phases in each layer were identified using X-ray Diffraction. The effects of the experimental conditions such as temperature and nitriding time on the kinetics of nitrogen diffusion were investigated. The nitrogen content within the samples was increased with increasing temperature and nitriding time. Correlations between microhardness and the nitrogen concentration have been developed for the phase(s) present in the core and the outer layers. The diffusion of nitrogen in solid titanium was simulated numerically, and the predicted nitrogen concentration profile in the rods and displacement of Ti–N phase interfaces show good agreement with the experimental observations. Energy-dispersive X-ray spectroscopy and the numerical simulation results suggest that β phase boundary composition is 2.8 wt. % N, the α phase exists within the compositional range of 5.5–6.5 wt. % and the Ti–N phase within the compositional range 7.0–15.0 wt. %, which differs from data extracted from a published phase diagram. |
| Databáze: | OpenAIRE |
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