Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7966797 | Journal of Nuclear Materials | 2015 | 5 Pages |
Abstract
In order to study the effect of low temperature on microstructure of U-Nb alloy αⳠphase, and interpret the low temperature aging mechanism, the U-5.8 wt.%Nb alloy was investigated during aging at 200 °C using X-ray diffraction (XRD), in situ tensile test and transmission electron microscopy (TEM). The phase transformation of αâ³Â â γ° is found by XRD after aging 4 h at 200 °C. The γ° transforms to αⳠduring tensile test by stress-induced. The experimental results disclose that the phase transformation of γ° â αⳠoccurs at the stage of twinning (de-twinning) deformation. Therefore, the phase γ° formed during aging can hamper the deformation of twinning (de-twinning), and strengthens the alloy remarkably. The phase transformation between αⳠand γ° is reversible nanoscale martensitic transitions. The microstructure of dark/bright striations was found in TEM image, which present in both as-quenched and aged samples. The striations, made up of dislocation, are different from the structure of spinodal decomposition. The crystallography relationship of low temperature aging mechanism was also discussed in this paper.
Related Topics
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Nuclear Energy and Engineering
Authors
Yanzhi Zhang, Xiaolin Wang, Qinying Xu, Yufei Li,