콘텐츠 본문
논문 해외 국제전문학술지(SCI급) Understanding the Mechanism of Magnesiothermic Reduction for Direct Alloy Synthesis of Ti-Nb Alloys
- 학술지 구분 국제전문학술지(SCI급)
- 게재년월 2019-06
- 저자명 Kyunsuk Choi & Il Sohn*
- 학술지명 JOM [The Journal of The Minerals, Metals & Materials Society (TMS)]
- 발행국가 해외
- 논문언어 외국어
논문 초록 (Abstract)
A novel approach to directly produce Ti-Nb alloys through direct magnesiothermic reduction from intermediate TiNb2O7 (TNO) is demonstrated. Using a combination of X-ray diffraction, scanning electron microscope–energy dispersive spectroscopy, and scanning transmission electron microscopy, the observed phases, chemical composition, and crystal structure could be identified and the reaction pathway determined. Although thermodynamically favorable, the reductions carried out between 700°C and 900°C at various Mg/TNO stoichiometric molar concentrations showed 1.5 times the stoichiometric molar ratio (mass ratio Mg/TNO of 10.5) to produce Ti-Nb alloy products, but complete reduction was not possible owing to the depletion of Mg from vaporization and reactions. Excess amounts of Mg at 5 times the stoichiometric molar ratio (mass ratio Mg/TNO of 35) resulted in full reduction of the TNO powders to produce Ti-Nb alloys without Ti-Nb-Mg-O intermediate oxide phases. A comparison of the magnesiothermic reduction of the individual components, including TiO2, Nb2O5, and TNO, indicated the reduction of TiO2 to be complex and limiting, with reduction significantly easier for Nb2O5 and TNO at higher temperatures and excess Mg contents.
