拉拔形变中铼元素固溶无序化对钨铼丝导电性能的影响

Effect of Solution Disorder of Rhenium Element on the Electrical Conductivity of Tungsten-rhenium Wire during its Drawing Deformation

金属钨因其高熔点、高密度和优异的高温性能,在电子器件、加热元件和辐射防护等方面有着广泛应用。通过添加铼元素固溶形成的钨铼合金被广泛应用于真空电子器件的核心材料,也是迄今为止对钨材料进行韧化最为有效的手段之一。在钨铼丝性能研究中,对于钨铼合金服役性能最为关键的电阻率指标却鲜有研究和报道,本试验通过对不同拉拔形变量的纯钨丝及W-20%Re合金丝的力学性能和电阻率变化趋势进行系统性研究。研究结果发现,相较于纯钨丝的抗拉强度和电阻率均随拉拔形变量上升而升高的特点,W-20%Re合金丝的电阻率随形变量的增加出现了两个具有显著差异的阶段。通过进一步的透射电镜显微结构、高分辨电镜下元素分布特征对比分析发现,该现象是由高温拉拔形变过程中钨铼合金中铼元素的均匀无序化固溶所造成的。

Tungsten is widely used in electronic devices,heating elements and radiation protection because of its high melting point,high density and excellent high temperature performance.Tungsten-rhenium alloy formed by solid solution addition of rhenium is widely used as the core material of vacuum electronic devices,and it is also one of the most effective means to toughen tungsten materials so far.In the research on the properties of tungsten-rhenium wires,the most critical resistivity index for the service performance of tungsten-rhenium alloys is rarely studied and reported.In this study,the mechanical properties and resistivity change trend of pure tungsten wires and W-20%Re alloy wires with different drawing deformation variables are systematically studied.It is found that compared with the characteristics that the tensile strength and resistivity of pure tungsten wire increase with the increase of drawing deformation,the resistivity of W-Re20 alloy wire has two distinct stages with the increase of drawing deformation.Through the further comparative analysis of the microstructure of transmission electron microscope and the distribution characteristics of elements under high-resolution electron microscope,it is found that this phenomenon is caused by the uniform and disordered solid solution of rhenium in tungsten-rhenium alloy during high-temperature drawing deformation.