Tool electrode wear is a severe problem in electrical discharge machining (EDM) which significantly affects the efficiency of the machining process and dimensional accuracy. In this paper, ultra-fine-grained (UFG) structures due to their unique and unusual properties are used to alleviate the wear problem of tool electrode. Equal-channel angular pressing (ECAP) is a novel severe plastic deformation metal forming process which can produce ultra-fine to nanoscale grains in bulk materials. Commercially pure copper was ECAP-ed to produce UFG microstructures and then used as tool electrode in EDM. The performance parameters in the EDM process, which have been studied, are material removal rate (MRR), volumetric electrode wear (VEW) and electrode wear ratio (EWR). For UFG and coarse-grained electrodes, the MRR, VEW and EWR obtained in EDM process have been compared. The results show that VEW and EWR decrease when UFG copper tool electrodes are used. But with increasing machining time, VEW and EWR of UFG copper electrodes approach those of the coarse-grained copper electrode.

工具电极的磨损是放电加工（EDM）中的一个严重问题，它严重影响加工过程的效率和尺寸精度。在本文中，由于超细晶粒（UFG）结构的独特和不寻常的性能，可用于缓解工具电极的磨损问题。等通道角挤压（ECAP）是一种新颖的严重塑性变形金属成型工艺，可以在散装材料中产生超细至纳米级的晶粒。用商业上纯的铜进行ECAP处理以生产UFG微观结构，然后在EDM中用作工具电极。已经研究过的EDM工艺中的性能参数是材料去除率（MRR），电极体积磨损（VEW）和电极磨损率（EWR）。对于UFG和粗颗粒电极，MRR 比较了在EDM工艺中获得的VEW和EWR。结果表明，使用UFG铜工具电极时，VEW和EWR降低。但是随着加工时间的增加，UFG铜电极的VEW和EWR接近于粗晶粒铜电极的VEW和EWR。