Powder mixed electrical discharge machining was used for the first time in the dressing of diamond grinding wheels. The electrical discharge process is greatly affected by the discharge medium. In this paper, compressed air (gas phase), deionized water mist (gas-liquid two-phase mixed state) and mixed silica powder medium (gas-liquid-solid three-phase mixed state) are used in the grinding wheel dressing experiments. The breakdown mechanism of the above these mediums is theoretically analyzed, and the size relationship of the discharge gap is obtained. The discharge gap detection results are in good agreement with the theoretical analysis results. The dressing results of the grinding wheel show that the dressing in the mixed powder medium can obtain the best surface morphology. In addition, the dressing efficiency in mixed powder medium is 65.71% and 163.63% higher than that in deionized water mist and compressed air, respectively. Finally, the grinding results show that the surface roughness of the YG8 cemented carbide obtained by the grinding wheel dressed in compressed air, deionized water mist, and mixed powder medium are 2.481 μm, 1.217 μm, and 0.973 μm, respectively. In summary, the mixed powder electrical discharge dressing method is an effective and high-quality dressing method for grinding wheels.

粉末混合放电加工首次应用于金刚石砂轮的修整。放电过程受放电介质影响很大。本文采用压缩空气（气相）、去离子水雾（气液两相混合状态）和混合二氧化硅粉介质（气液固三相混合状态）进行砂轮修整实验。从理论上分析了上述这些介质的击穿机理，得到了放电间隙的大小关系。放电间隙检测结果与理论分析结果吻合较好。砂轮修整结果表明，在混合粉体介质中修整可以获得最佳的表面形貌。此外，在混合粉介质中的修整效率为65。分别比去离子水雾和压缩空气高71%和163.63%。最后，磨削结果表明，用压缩空气、去离子水雾和混合粉末介质修整的砂轮得到的YG8硬质合金的表面粗糙度分别为2.481 μm、1.217 μm和0.973 μm。综上所述，混合粉末放电修整法是一种有效且高质量的砂轮修整方法。