Valence bond structure of Ta-W alloys

doi:10.1016/S1006-7191(08)60099-X

Acta Metallurgica Sinica (English Letters) ›› 2009, Vol. 22 ›› Issue (4): 275-283.DOI: 10.1016/S1006-7191(08)60099-X

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Valence bond structure of Ta-W alloys

Xiaobo LI^1,2,Youqing XIE³

1) School of Mechanical Engineering,Xiangtan University, Xiangtan 411105, China
2) Key Laboratory of Materials Design and Preparation Technology of HunanProvince, Xiangtan University, Xiangtan 411105,China
3) School of Material Science and Engineering, Central South University, Changsha 410083, China

Received:2008-09-09 Revised:2008-12-09 Online:2009-08-25 Published:2009-10-10
Contact: Xiaobo LI

Abstract

Abstract:

The valence bond structure of substitutional BCC based Ta-W alloys is studied using characteristic crystal (CC) theory. This theory is based on cluster statistics of random alloys. By studying the correlativity between energy and volume of the CC in Ta-W alloys, the valence bond structure of CC is determined by the energy and shape method. Then, following additive law of CC, the valence bond structure of Ta-W alloys is calculated. It is found that the outer shell valence electronic distribution of Ta-W alloys shows a continuous change in the whole composition range. The covalent electrons e_c(d_c, s_c, and p_c) increase, whereas near free electrons e_f decrease with increasing W concentration. The bond length and single-bond radius decrease, whereas bond energy and bond valence increase with increasing W concentration. The mechanism of solid solution strengthening of Ta-W alloys is analyzed based on their valence bond structure.

Key words: Valence bond structure, Ta-W alloys

Xiaobo LI,Youqing XIE. Valence bond structure of Ta-W alloys[J]. Acta Metallurgica Sinica (English Letters), 2009, 22(4): 275-283.

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