Synthesis of niobium borides by powder metallurgy methods using Nb2O5, B2O3 and Mg blends

被引：23

作者：

Balci, Ozge ^{[1
]}

Agaogullari, Duygu ^{[1
]}

Ovecoglu, M. Lutfi ^{[1
]}

Duman, Ismail ^{[1
]}

机构：

[1] Istanbul Tech Univ, Particulate Mat Labs, Dept Met & Mat Engn, Fac Chem & Met Engn, Ayazaga Campus, TR-34469 Istanbul, Turkey

来源：

TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA | 2016年 / 26卷 / 03期

关键词：

niobium boride powders; powder metallurgy; mechanochemical synthesis; annealing; microstructure; SOLID-STATE REACTION; NB-B; COMBUSTION SYNTHESIS; SUPERCONDUCTIVITY; REDUCTION; PHASE;

D O I：

10.1016/S1003-6326(16)64165-1

中图分类号：

TF [冶金工业];

学科分类号：

0806 ;

摘要：

Niobium boride powders having NbB, NbB2 and Nb3B4 phases in various amounts and single phase NbB powders were successfully synthesized by using powder metallurgy methods from related metal oxide raw materials in the presence of a strong reducing agent. Nb2O5, B2O3 and Mg powder blends were milled at room temperature by a high-energy ball mill for different time. Subsequently, undesired MgO phase was removed from the milled powders by HCl leaching to constitute NbB-NbB2-Nb3B4 as final products and they were subjected to an annealing process at 1500 degrees C for 4 h to observe probable boride transformation. Characterization was carried out by XRD, DSC, PSA, SEM/EDX, TEM and VSM. The effects of milling time (up to 9 h) on the formation, microstructure and thermal behavior of the final products were investigated. Reduction reaction took place after milling stoichiometric powder blends for 2 h. Nano-sized NbB-NbB2-Nb3B4 powders in high purity were obtained in the absence of any secondary phase and any impurity via mechanochemistry by milling for 5 h and leaching with 4 mol/L HCl. After annealing, pure and nano-sized NbB-NbB2-Nb3B4 powders transformed to a single NbB phase without leaving behind NbB2 and Nb3B4 phases.

引用

页码：747 / 758

页数：12

共 34 条

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