期刊
ACTA MATERIALIA
卷 196, 期 -, 页码 122-132出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.actamat.2020.06.023
关键词
Vanadium; Oxygen solutes; Hardening; Dislocation debris; Cross-slip
资金
- National Natural Science Foundation of China [51922082, 51971170, 51942104]
- National Key Research and Development Program of China [2017YFB0702301]
- 111 Project of China [BP2018008]
- Innovation Project of Shaanxi Province [2017KTPT-12]
Vanadium (V) is sensitive to minute quantity of oxygen interstitials, which induce pronounced hardening and embrittlement. Here, we utilize oxygen to synthesize V solid solutions in order to reveal the mechanism of oxygen solutes induced hardening. With increasing of oxygen solute concentrations, the fracture modes of V samples transform from dimple, to a mixture of dimple and cleavage, and to a fully trans-granular cleavage. High density of dislocations and dislocation debris are produced in strained samples. The mobility of screw dislocations is reduced and the dislocation cross-slip events are promoted by oxygen solutes. In addition to oxygen solution hardening, the generation of high density of oxygen-vacancy complexes plays a dominant role in the strengthening. High quantity of loop-shaped dislocation debris are direct evidence for the formation of oxygen-vacancy complexes. Profuse oxygen-vacancy complexes trap dislocations, promote cross-slips and assist dislocation storage, thus give rise to a superior combination of strengthening, strain hardening, and ductility in V with 1.0 at% of oxygen. Once beyond a critical oxygen concentration (>1.6 at%), V shows catastrophic brittle failure due to the exceptional high density of oxygen-vacancy complexes. These findings provide insight to design high performance refractory metals utilizing oxygen solutes. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据