Cathode ablation is one of the dominant limitations for extending the maximum operating time of arc heaters. In this work, the arc ablation behaviors and mechanisms of commercial CuCr10, CuCr25, and CuCr50 cathodes were investigated for pure copper and pure chromium cathodes. The discharging homogeneity was improved with the increase of chromium content in the cathodes, which was attributed to the formed chromic oxide layer. The CuCr50 cathodes exhibited the lowest ablation rate with a reduction of 27.0% compared to the copper cathodes. The chromic oxide formed in the pit protected the bottom matrix, leading to a homogeneous ablation process. The mechanism for the improved homogeneous ablation behaviors of the CuCr50 cathodes was proposed and featured by the suppression of deep pits and the dispersion of arc foot. Future attention will be focused on designing composite cathodes with an anti-ablation surface layer and a good conductive matrix.

阴极消融是延长电弧加热器最大工作时间的主要限制之一。在这项工作中，研究了纯铜和纯铬阴极的商业化CuCr10，CuCr25和CuCr50阴极的消弧行为和机理。随着阴极中铬含量的增加，放电均匀性得到改善，这归因于形成的氧化铬层。与铜阴极相比，CuCr50阴极表现出最低的烧蚀率，降低了27.0％。在凹坑中形成的氧化铬保护了底部基质，从而导致了均匀的烧蚀过程。提出了改善CuCr50阴极均匀烧蚀性能的机理，其特点是抑制了深坑和电弧足的分散。