【摘要】 在左手超材料电磁传输性能的稳健性设计中,变形对其组分材料铜电导率的影响必须予以考虑,文章基于该基本变形形式展开研究,从把控材料源头着手,通过扭转变形实验制备了纯铜扭转试棒,并按照直流双臂电桥测试方案对纯铜扭转试棒进行了纯铜电导率的测定实验,结果表明纯铜电导率随扭转角的增大而减小,且减小的幅度随扭转角的增大而趋缓;基于实验测得的关系曲线使用数据拟合的方式建立了纯铜电导率关于扭转角的影响模型(幂函数);借助试棒扭转变形的金相实验结果,从固体能带理论探讨了扭转变形对纯铜电导率影响模型的内在机理,发现随着扭转角的增大,纯铜扭转试棒的金相组织晶粒度同步增大,变形初期晶格内部位错增殖且晶界显著增加,从而导致纯铜导电性能的降低,但随着变形的累加,材料晶格缺陷的分布趋于均匀,在一定程度上减缓了纯铜扭转电导率的下降速率。更多还原

【Abstract】 The influence of the deformation of left-handed metamaterial component copper material on copper conductivity must be taken into account in the robust design for transmission performance of left-handed metamaterials. On this basis, the influence of torsional deformation is studied in this paper. Firstly, based on the control of copper material source, the preparation of pure copper test specimens of torsional deformation is completed through a standard torsion experiment. Then according to a test program of the DC double armed bridge, the measurement of copper conductivity under torsional deformation is carried out, the influence of torsion angle on copper conductivity is studied, and the related influence curve is plotted. It is found that copper conductivity decreases with the increase of torsion angle, and the decreasing amplitude of copper conductivity slows down gradually. Subsequently, an influence model(power function) for copper conductivity regarding torsion angle is proposed through data fitting based on the influence curve. Finally, from the perspective of band theory in solid physics, the intrinsic mechanism of the influence model is discussed with the help of the metallographic results of torsional deformation; and it is found that the grain size of metallographic microstructure for copper test specimens of torsional deformation increases synchronously with the increase of torsion angle. At the initial stage of the torsional deformation, the main reason for the decreased copper conductivity is that the dislocation multiplication leads to a significant increase of the grain boundary. However, with the accumulation of deformation, the distribution of lattice defects tends to be uniform, so the decreasing rate of copper conductivity slows down to some extent.更多还原