Ma Tangpeng, Wang Jin, Zhou Jixue, Qin Jingyu, Cheng Kaiming, Yu Huan, Zhao Dongqing, Yang Huabing, Zhan Chengwei, Zhao Guochen, Li Xinxin
Shandong Provincial Key Laboratory of High Strength Lightweight Metallic Materials, Advanced Materials Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China.
School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, China.
Materials (Basel). 2024 Oct 15;17(20):5032. doi: 10.3390/ma17205032.
The formation criteria of the LPSO phase are important for the design of long-period stacking-ordered (LPSO) Mg alloys. This work focuses on Type I LPSO Mg-Y-X alloys and attempts to explore the formation criteria of the LPSO phase from the perspective of liquid-solid correlation. With the aid of molecular dynamics simulation, liquid Mg-Y-X alloys are investigated to obtain the common liquid characteristics from the reported Type I LPSO Mg-Y-X alloys. Following the liquid characteristics, a new Type I LPSO alloy, i.e., Mg-Y-Au, is experimentally confirmed. The discovery of a new Type I LPSO alloy supports liquid-solid correlation, and hence, the formation criteria of the LPSO phase in Type I LPSO alloys can be developed based on the common liquid characteristics of Type I LPSO Mg-Y-X alloys as follows: X should result in the reduction in equilibrium volume and cohesive energy; Y should repulse Y and be attracted by both Mg and X, and X should be repulsed by both Mg and X; X should enhance the threefold and fourfold symmetries and weaken the fivefold and sixfold ones so that the local structural symmetries are distributed close to liquid pure Mg.
长周期堆垛有序（LPSO）镁合金的设计中，LPSO相的形成准则至关重要。本文聚焦于I型LPSO镁 - 钇 - X合金，试图从液 - 固相关性的角度探索LPSO相的形成准则。借助分子动力学模拟，对液态镁 - 钇 - X合金进行研究，以从已报道的I型LPSO镁 - 钇 - X合金中获取常见的液态特征。依据这些液态特征，通过实验证实了一种新型I型LPSO合金，即镁 - 钇 - 金合金。新型I型LPSO合金的发现支持了液 - 固相关性，因此，基于I型LPSO镁 - 钇 - X合金的常见液态特征，可得出I型LPSO合金中LPSO相的形成准则如下：X应导致平衡体积和内聚能降低；Y应排斥Y且被Mg和X吸引，而X应被Mg和Y排斥；X应增强三重和四重对称性并削弱五重和六重对称性，以使局部结构对称性分布接近液态纯镁。
