长寿命铜钨合金气体开关电极的烧蚀形貌

Surface Morphology of Cu-W Alloy Electrodes in a Long Lifetime Gas Spark Switch

研究密闭腔内结构紧凑、长寿命、大通流能力且能重复频率稳定工作的气体开关,对于油气开发中应用的脉冲功率装置意义重大。从工程实际出发,开展了对铜钨电极烧蚀形貌与相关特性的系统研究。搭建了开关实验平台,模拟实际工程中开关的变化过程。通过接触式非球面测量仪、共聚焦显微镜等设备完成对不同寿命阶段电极表面形貌的观测,得到表面轮廓线、平面显微图像,以及3维重建模型等数据,定量表述电极表面烧蚀形貌。结果表明,随着累计转移电荷量的增加,阳极、阴极的表面粗糙度均明显增加,且边缘区较中心区具有更高的粗糙度;对于同一区域,阴极都具有更高的粗糙度;20000次自击穿放电后,表面粗糙度增加至7.752?m(阴极,边缘)与5.573?m(阳极,边缘)。总体而言,阴极较阳极烧蚀更为严重,多次放电后表面形貌复杂,难以用简单模型描述。该研究是对传统气体开关技术的重要补充,具有相当的科研价值,同时也对油气开发等工业应用实际具有重要借鉴意义。

Considering the complex circumstances in real applications such as the underground mine environment, the gas switch is required for long lifetime, high current capability, repetition rate, small breakdown voltage variance while working in a small sealed cavity. In order to simulate the electrode erosion process and acquire the performance of the two electrode switch resembling the ones in the practical application, a simple test platform had been designed and fabricated. A Dynamic 3-D Aspheric Profiler and a Confocal Laser Scanning Microscope（CLSM） were utilized to help analyze the erosion characteristics by providing quantitative descriptions of 1-D, 2-D, and 3-D profiles. The results demonstrate that the surface roughness of both electrodes rose with the increase of accumulated transfer charge. Specifically, the edge position has a larger value of surface roughness than the central position. Moreover, the surface of cathode seems rougher than that of anode in the same area. For example, the surface roughness of cathode was 7.752？m at edge position whereas that of anode was 5.573？m after 20000 shots. In sum, the erosion in cathode is more severe and the surface morphology is too complex to be described by simple models. Therefore, the research of the two electrode gas switch under such rigorous conditions can both investigate the new phenomena which are not concerned before and provide useful guidance to the applications. Thus, this research is essential in scientific research and industrial applications.