Scientific Reports
·
2021
·Vol. 11
·期 1
·1-11
·
IF 4.38
Wang Jingfeng,Zhang Yue,Liu Fang,Li Qingkui
Considering the problem of high oxygen content in industrial niobium powder, the oxygen reduction of high oxygen niobium powder with the addition of magnesium is studied. Based on the thermodynamic analysis of magnesium thermal reduction of niobium powder, the effects of reduction temperature, magnesium addition, reduction time, and reduction atmosphere on the oxygen content of pickling niobium powder are studied. The results show that with an increase in the magnesium addition, the oxygen content of pickling niobium powder gradually decreases to a certain value, and then remains unchanged. In a certain temperature range (953–1203 K), with an increase in the reduction temperature, the oxygen content of pickling niobium powder first decreases, and then increases; the best oxygen content is 356 ppm at 1133 K. With the extension in reduction time (2–6 h), the oxygen content of pickling niobium powder first decreases, and then remains unchanged. Finally, the oxygen content of pickled niobium powder is reduced to approximately 356 ppm at 400% magnesium addition at 1133 K for 4 h.
研究领域:
材料科学
·
冶金学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
·
2022
·
IF 3.752
Xue-yi GUO,Zhao-wang DONG,Yang XIA,Pei-dong LIU,Han-ning LIU,Qing-hua TIAN
A high-purity Ti–48Al–2Nb–2Cr alloy powder with an oxygen content as low as 0.0572 wt.% and a particle size of <150 μm was produced from a mixture of TiO 2 , Al 2 O 3 , Nb 2 O 5 , and Cr 2 O 3 powders through reduction with magnesium and deoxidation with calcium. The phase and composition of the products were analyzed. The final product mainly included γ -TiAl and minor α 2 -Ti 3 Al phases, and Ti, Al, Cr, and Nb were homogenously distributed in the powder with a mole ratio of 49.73:43.51:2.05:1.98. The reduction and deoxidation mechanisms were investigated by thermodynamic modeling using the HSC Chemistry software and Pandat software based on the Ti alloy database.
研究领域:
材料科学
·
冶金工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Central South University
·
2022
·Vol. 29
·期 6
·1811-1822
·
IF 2.392
Dong Zhao-wang,Xia Yang,Guo Xue-yi,Liu Han-ning,Liu Pei-dong
Ti-6Al-4V alloy powder was prepared through a two-step reduction of a mixture of TiO 2 , V 2 O 5 and Al 2 O 3 in this study. The oxide mixture was first reduced by Mg in MgCl 2 at 750 °C in argon, where oxygen was reduced to 2.47 wt% from 40.02 wt%. The oxygen content in the final powder was eventually reduced to an extremely low level (0.055 wt%) using calcium at 900 °C in argon, and the final powder had the composition of 90.12 wt% Ti, 5.57 wt% Al, and 3.87 wt% V, which meets the standard specification of Ti-6Al-4V (ASTM F1108-09). Between the two reductions, a heat treatment step was designed to help controlling the specific surface area and particle size. The effect of the heat treatment temperature on the morphology, and composition uniformity of the powder was investigated in detail. Heat treatment above 1300 °C attributed to a dense powder with a controlled specific surface area. Thermodynamic modeling and experimental results indicated that only α -Ti enriched with Al and β-Ti enriched with V exist in the final powder, and other possible phases including Al-Mg and Al-V were excluded. This study also offers a triple-step thermochemical process for producing high-purity Ti-based alloy powder.
研究领域:
材料科学
·
冶金工程
✓ 已验证
产品关联
DOI
高影响因子
JOM
·
2019
·Vol. 72
·期 4
·1687-1693
·
IF 2.305
Xia Yang,Zhao Jinlong,Dong Zhaowang,Guo Xueyi,Tian Qinghua,Zhang Siwen,Liu Yong
Ultra-high pure metallic zirconium powder was successfully obtained through a two-step gradient reduction of nano-ZrO 2 in Ar atmosphere. The first reduction by Mg was to remove ~ 85% oxygen, followed by a heat-treatment step to control the particle size and specific surface area of the powder, and the final reduction by calcium was to further purify the powder and decrease oxygen to an extremely low level (0.068 wt.%). The oxygen level in the final powder meets the standard specification of Zr sponge (ASTM B349/B349M-16). Processing parameters, including the reduction temperature, the amount of Mg and MgCl 2 and the heat treatment temperature, were investigated. Thermodynamic modeling with the assistance of HSC Chemistry software was carried out to understand the reduction reaction. This study offers a novel process for producing ultra-high pure metallic zirconium powder with the potential to replace the conventional Kroll process.
研究领域:
材料科学
·
冶金学
✓ 已验证
DOI
高影响因子
POWDER TECHNOLOGY
·
2020
·
IF 4.142
Zhaowang Dong,Yang Xia,Xueyi Guo,Jinlong Zhao,Linfeng Jiang,Qinghua Tian,Yong Liu
Upgraded titania slag (UGS) is a titanium-rich material with over 90 wt% titanium dioxide and some minor elements such as Fe, Al, Cr, and Si, which is mainly used for preparing TiO 2 and TiCl 4 . In this study, UGS was directly reduced with magnesium powder in a hydrogen atmosphere. Titanium alloy hydride powder with the oxygen content of 0.032 wt% was obtained. The minor elements of Fe, Si, Al, and Cr from the UGS were kept in the final powder with the main phase of TiH 1.924 (δ), and minor intermetallic phases of HFe 2 Ti, Ti 5 Si 3 H 0.9 and Cr 1.8 TiH 5.3 . EDS elemental mapping results indicated that HFe 2 Ti and Ti 5 Si 3 H 0.9 intermetallics formed bright phase islands in the matrix. The reduction mechanism and the reaction sequence were discussed based on the thermodynamic modelling with the assistance of HSC chemistry software. The possibility of hydrogen reduction of titanium oxides was discussed as well.
研究领域:
材料科学
·
冶金工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2017
·
IF 6.395
Hanna He,Qi Zhang,Haiyan Wang,Hehe Zhang,Jiadong Li,Zhiguang Peng,Yougen Tang,Minhua Shao
Inferior electronic conductivity and sluggish sodium ion diffusion are still two big challenges for TiO 2 anode material for Na ion batteries (SIBs). Herein, we synthesize TiO 2 /C composites by the pyrolysis of MIL-125(Ti) precursor and successfully introduce defects to TiO 2 /C composite by a simple magnesium reduction. The as-prepared defect-rich TiO 2-δ /C composite shows mooncake-shaped morphology consisting of TiO 2-δ nanocrystals with an average particle size of 5 nm well dispersed in the carbon matrix. When used as a SIBs anode, the defect-rich TiO 2-δ /C composite exhibits a high reversible capacity of 330.2 mAh g −1 at 50 mA g −1 at the voltage range of 0.001–3.0 V and long-term cycling stability with negligible decay after 5000 cycles. Compared with other four TiO 2 /C samples, the electrochemical performance of defect-rich TiO 2-δ /C is highly improved, which may benefit from the enhanced electronic/ionic conductivities owing to the defect-rich features, high surface area rendering shortened electronic and ionic diffusion path , and the suppress of the TiO 2 crystal aggregation during sodiation and desodiation process by the carbon matrix.
研究领域:
材料科学
·
能源存储
·
纳米技术
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）