Center for Computational Study of Microstructure Evolution in Materials and Multi-Disciplinary Materials Research Center, Frontier Institute of Science and Technology, State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China.
Phys Rev Lett. 2010 Nov 12;105(20):205702. doi: 10.1103/PhysRevLett.105.205702. Epub 2010 Nov 11.
Recent experiments have revealed a rich variety of strain states in doped ferroelastic systems. We study the origin of two abnormal strain states; precursory tweed and strain glass, and their relationship with the well-known austenite and martensite (the para- and ferroelastic states). A Landau free energy model is proposed, which assumes that point defects alter the global thermodynamic stability of martensite and create local lattice distortions that interact with the strain order parameters and break the symmetry of the Landau potential. Phase field simulations based on the model have predicted all the important signatures of a strain glass found in experiment. Moreover, the generic "phase diagram" constructed from the simulation results shows clearly the relationships among all the strain states, which agrees well with experimental measurements.
最近的实验揭示了掺杂铁弹性系统中丰富多样的应变状态。我们研究了两种异常应变状态的起源；前驱 tweed 结构和应变玻璃，以及它们与熟知的奥氏体和马氏体（顺磁和铁磁弹性状态）的关系。提出了一个朗道自由能模型，该模型假设点缺陷改变了马氏体的整体热力学稳定性，并产生了与应变有序参数相互作用并破坏朗道势对称性的局部晶格畸变。基于该模型的相场模拟预测了实验中发现的应变玻璃的所有重要特征。此外，从模拟结果构建的通用“相图”清楚地显示了所有应变状态之间的关系，这与实验测量结果吻合得很好。
