The effect of Sn concentration on oxide texture and microstructure formation in zirconium alloys
The effect of Sn concentration on oxide texture and microstructure formation in zirconium alloys
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DOI：
10.1016/j.actamat.2015.08.005
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发表时间：
2015-10
期刊：
影响因子：
9.4
通讯作者：
A. Garner;Jing Hu;A. Harte;P. Frankel;C. Grovenor;S. Lozano-Perez;M. Preuss
中科院分区：
文献类型：
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作者：
A. Garner;Jing Hu;A. Harte;P. Frankel;C. Grovenor;S. Lozano-Perez;M. Preuss
使用扫描电子显微镜（SEM）中的透射菊池衍射（TKD）和透射电子显微镜（TEM）中的自动晶体取向映射，研究了在具有不同Sn含量的两种锆合金（Zr-1 Nb-1 Sn-0.1Fe，即ZIRLO™和Zr-1.0Nb-0.1Fe）上形成的氧化物织构和显微组织的发展。为了量化和比较氧化物宏观织构的发展，还使用电子背散射衍射（EBSD）进行批量织构测量。无Sn合金通过延迟过渡区和降低氢吸收水平而显示出显著改善的腐蚀性能。氧化膜的宏观织构和晶粒取向差分析表明，改善的腐蚀性能和减少的氢吸收可以与增加的氧化物织构强度相关，改善的氧化物晶粒取向导致更长、更保护的柱状晶粒生长。在不含Sn的合金中也观察到较低的四方相分数。这导致在氧化物生长过程中较少的转化为稳定的单斜相，这导致减少的开裂和互连的孔隙度，并且还导致形成较大的、排列良好的单斜晶粒。得出的结论是，Zr-1.0Nb-0.1Fe合金是更耐吸氢由于形成一个更致密的氧化物与更大的柱状晶结构。
The development of oxide texture and microstructure formed on two zirconium alloys with differing Sn contents (Zr–1Nb–1Sn–0.1Fe, i.e. ZIRLO™ and Zr–1.0Nb–0.1Fe) has been investigated using transmission Kikuchi diffraction (TKD) in the scanning electron microscope (SEM) and automated crystal orientation mapping in the transmission electron microscope (TEM). Bulk texture measurements were also performed using electron backscatter diffraction (EBSD) in order to quantify and compare the oxide macrotexture development. The Sn-free alloy showed significantly improved corrosion performance by delay of the transition region and reduced levels of hydrogen pickup. The macroscopic texture and grain misorientation analysis of the oxide films showed that the improved corrosion performance and reduced hydrogen pick up can be correlated with increased oxide texture strength, the improved oxide grain alignment resulting in longer, more protective columnar grain growth. A lower tetragonal phase fraction is also observed in the Sn-free alloy. This results in less transformation to the stable monoclinic phase during oxide growth, which leads to reduced cracking and interconnected porosity and also to the formation of larger, well-aligned monoclinic grains. It is concluded that the Zr–1.0Nb–0.1Fe alloy is more resistant to hydrogen pickup due the formation of a denser oxide with a larger columnar grain structure.