Xie Hongbo, Bai Junyuan, Pan Hucheng, Pang Xueyong, Ren Yuping, Sun Shineng, Wang Liqing, Zhao Hong, Liu Boshu, Qin Gaowu
Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Materials Science and Engineering, Northeastern University, Shenyang 110819, People's Republic of China.
IUCrJ. 2018 Oct 26;5(Pt 6):823-829. doi: 10.1107/S205225251801415X. eCollection 2018 Nov 1.
This paper reports a new structured prismatic platelet, self-assembled by an ellipse-like quasi-unit cell, precipitated in Mg-In-Yb and Mg-In-Ca ternary alloys and aged isothermally at 200°C using aberration-corrected high-angle annular dark-field scanning transmission electron microscopy combined with density functional theory computations. The ordered stacking of solute atoms along the [0001] direction based on elliptically shaped self-adapted clustering leads to the generation of the quasi-unit cell. The bonding of these ellipse-like quasi-unit-cell rods by the Mg atomic columns along the 〈〉 directions formed a two-dimensional planar structure, which has three variants with a {} habit plane and full coherence with the α-Mg matrix. This finding is important for understanding the clustering and stacking behaviors of solute atoms in condensed matter, and is expected to guide the future design of novel high-strength Mg alloys strengthened by such high-density prismatic platelets.
本文报道了一种新型的结构化棱柱形析出相，它由类椭圆准晶胞自组装而成，在Mg-In-Yb和Mg-In-Ca三元合金中析出，并在200°C下进行等温时效处理。采用像差校正的高角度环形暗场扫描透射电子显微镜结合密度泛函理论计算对其进行了研究。溶质原子基于椭圆形自适应聚集沿[0001]方向有序堆积，导致了准晶胞的产生。这些类椭圆准晶胞棒通过Mg原子列沿〈〉方向键合形成二维平面结构，该结构具有三个以{}为惯习面且与α-Mg基体完全共格的变体。这一发现对于理解凝聚态物质中溶质原子的聚集和堆积行为具有重要意义，并有望指导未来通过这种高密度棱柱形析出相强化的新型高强度镁合金的设计。
