Effect of alloying elements on defect evolution in Ni-20X binary alloys
Effect of alloying elements on defect evolution in Ni-20X binary alloys
复制标题
DOI：
10.1016/j.actamat.2018.03.054
复制
发表时间：
2018-06
期刊：
影响因子：
9.4
通讯作者：
Tai-ni Yang;Chenyang Lu;G. Velişa;K. Jin;Pengyuan Xiu;M. Crespillo;Yanwen Zhang;H. Bei;Luming W
中科院分区：
文献类型：
--
作者：
Tai-ni Yang;Chenyang Lu;G. Velişa;K. Jin;Pengyuan Xiu;M. Crespillo;Yanwen Zhang;H. Bei;Luming W
利用离子辐照和截面透射电镜研究了合金元素对Ni和Ni-20 X（X = Fe，Cr，Mn和Pd）二元合金辐照诱导组织演变的影响。三维迁移模式被确定为这些二元合金中的间隙原子团簇的主要迁移机制，相反，在充分研究的稀合金中占主导地位的一维模式。结果表明：（1）缺陷团簇的平均尺寸随溶质原子体积尺寸因子的增大而减小。与Ni-20 Fe相比，Ni-20 Cr中的空位尺寸较小，这是由于近表面区域的空位迁移率较快，而辐照峰后的空位结合能较弱。在Ni-20 Mn和Ni-20 Pd中观察到的超过损伤峰的较小空隙是由于大尺寸溶质原子的更强的Mn/Pd-空位结合效应。(2)吸附的溶质可以作为有害物质的强捕获位点。溶质原子的体积因子越大，俘获力越强。这导致更明显缓慢的间隙迁移和更小的位错环尺寸。Ni-20 Fe中的平均位错环尺寸比Ni-20 Pd大4倍（原子体积因子分别为10.6%和41.3%），但密度低一个数量级。Ni-20 Cr合金中位错环尺寸较小是由于Cr-Ni间较强的间隙结合所致。总的来说，在集中的二元合金比在稀二元合金的缺陷的合金化效果更显着，由于在主要照射区域的合金化原子的浓度差和间隙占主导地位的迁移机制。
The effect of alloying elements on radiation-induced microstructural evolution in Ni and Ni-20X (X = Fe, Cr, Mn and Pd) binary alloys was investigated using ion irradiation and cross-sectional transmission electron microscopy. The three-dimensional migration mode is identified to be the dominating migration mechanism for interstitial clusters in these binary alloys, contrary to the one-dimensional mode that dominates in the well-studied dilute alloys. The results reveal that: (1) the average size of defect clusters decreases as the solute atomic volume size factor increases. Smaller void size in Ni-20Cr is attributed to faster vacancy mobility in the near surface region, and weaker vacancy binding energy beyond the irradiation peak than Ni-20Fe. The smaller voids observed in Ni-20Mn and Ni-20Pd beyond the damage peak are due to the stronger Mn/Pd-vacancy binding effect of largely oversized solute atoms. (2) Oversized solutes can act as strong trapping sites for interstitials. The larger the solute atomic volume factor, the stronger the trapping force. This leads to a more significantly sluggish interstitial migration and smaller dislocation loop size. The average dislocation loop size in Ni-20Fe was four times larger than Ni-20Pd (atomic volume factor being 10.6% and 41.3%) but an order of magnitude lower in density. The smaller dislocation loop size in Ni-20Cr is attributed to stronger interstitial binding of Cr-Ni. Overall, the alloying effect on defects is more significant in concentrated binary alloys than in dilute binary alloys, due to the concentration difference of alloying atoms and the interstitial dominant migration mechanisms in the main irradiated region.