Effects of oxygen concentration and phase stability on nano-domain structure and thermal expansion behavior of Ti-Nb-Zr-Ta-O alloys
Effects of oxygen concentration and phase stability on nano-domain structure and thermal expansion behavior of Ti-Nb-Zr-Ta-O alloys
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DOI：
10.1016/j.actamat.2015.08.054
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发表时间：
2015-11-01
期刊：
影响因子：
9.4
通讯作者：
Miyazaki, Shuichi
中科院分区：
文献类型：
--
作者：
Wei, Le Si;Kim, Hee Young;Miyazaki, Shuichi
为了全面阐明胶质金属纳米畴结构和异常热膨胀行为的成因，研究了氧浓度、β相稳定性和冷轧对（Ti-xNb-2 Zr-0.7Ta）-yO（at.%）（x = 21-25; y = 0.3-1.8）合金。正常的热膨胀行为与积极的线性热膨胀系数，观察到在所有退火的合金，无论氧和铌浓度。轧制态合金的热膨胀行为受氧和铌浓度的强烈影响。一个负的热膨胀系数，观察到在轧制的合金与较低的氧和铌浓度。热膨胀系数随着氧和Nb浓度的增加而增加。纳米畴的数量随着氧浓度的增加而增加，而随着Nb浓度的增加而减少。在轧制态合金中观察到优先纳米畴变体的生长，并且随着氧和Nb浓度的降低而变得更加突出。随着温度的升高，从纳米畴结构到β相的逆转变发生。轧制态合金的热膨胀行为是由纳米畴结构的晶格畸变贡献和β相的晶格振动贡献之间的竞争关系引起的。(C)2015 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
In this study, in order to fully elucidate the origin of nano-domain structure and abnormal thermal expansion behavior of Gum metals, the effects of oxygen concentration, beta phase stability and cold rolling on the microstructure and thermal expansion properties were investigated in (Ti-xNb-2Zr-0.7Ta)-yO (at.%) (x = 21-25; y = 0.3-1.8) alloys. Normal thermal expansion behaviors with positive linear thermal expansion coefficients were observed in all the annealed alloys irrespective of oxygen and Nb concentrations. The thermal expansion behavior of as-rolled alloys was strongly affected by the concentration of oxygen and Nb. A negative thermal expansion coefficient was observed in the as-rolled alloys with lower oxygen and Nb concentrations. The thermal expansion coefficient increased with increasing oxygen and Nb concentrations. The amount of nano-domains increased with increasing oxygen concentration while decreased with increasing Nb concentration. The growth of a preferential nano-domain variant was observed in as-rolled alloys and became more prominent with decreasing oxygen and Nb concentrations. The reverse transformation from the nano-domain structure to the beta phase occurred with increasing temperature. Thermal expansion behavior of as-rolled alloys resulted from a competing relationship between the contribution of lattice distortion of nano-domain structure and the contribution of lattice vibration of the beta phase. (C) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.