非均匀超导薄膜-基体系统中的界面开裂与失超研究

Since the discovery of the high temperature superconductors (HTS), superconducting materials have been widely used. One of the applications is superconducting thin film. In the nonhomogeneous superconducting thin film-substrate system, due to the dislocation and thermal expansion, the interface cracks will be generated between superconducting thin film and substrate. These cracks will be propagated under the external magnetic field, which will greatly affect the application of superconducting thin films. Even the superconducting materials will lose its superconductivity, thus resulting in quench. Therefore, this project studies nonlinear electromagnetic physics and multi-field coupling problems. We focus on the basic subjects of the nonhomogeneous high temperature superconductor which are interfacial crack of superconducting thin film-substrate system and the relationship between quench condition and control parameters as well as material instability. Numerical modeling, quantitative analysis, and basic experimental measurement are involved in the project. The research provides the basic analytical framework and methodology for the application of superconducting thin film in engineering.

自高温超导体发现以来，超导材料得到了广泛的应用，其中之一是超导薄膜的应用。在非均匀超导薄膜-基体系统中，由于位错、热膨胀等的作用，在超导薄膜和基体之间产生界面裂纹，这些裂纹在外磁场作用下将会扩展，这将极大的影响超导薄膜的应用，甚至会对超导材料性能产生影响而发生失超。本项目针对非均匀高温超导材料的非线性电磁物理与多场耦合问题，开展有关超导薄膜-基体之间的界面裂纹、失超条件与外界控制参数的关联以及材料失稳等高温超导材料中关注的基础性课题展开理论与数值建模、定量分析和基本实验测量研究，为超导薄膜在应用中的力学设计提供基本的分析框架和方法。

本项目研究了超导材料安全运行中的关键力学问题。为了研究超导材料在时变磁场下的安全运行问题，我们分析了超导体与基体界面断裂以及多级超导电缆的力学行为。首先，研究了非均匀超导-基体界面的开裂问题；其次，对于超导应用中的失超问题，系统地研究了多级超导电缆的力学行为；最后，针对CWS设计的电缆，研究了其接触行为和拉伸刚度的问题。本项目针对高温超导材料的非线性电磁物理与多场耦合问题，开展了超导薄膜-基体之间的界面裂纹、力对失超的影响以及材料失稳等高温超导材料中关注的基础性课题展开理论与数值建模、定量分析和基本实验测量研究，为超导材料在应用中的力学设计提供基本的分析框架和方法。