Experimental study on silica powder mixed electrical discharge dressing of coarse diamond grinding wheel. (January 2022) - Dai, Longzhou
Abstract: 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. Highlights: Powder mixed electric discharge machining was used for the first time in the dressing of diamond grinding wheels. Compressed air, deionized water mist and mixed silica powder medium are used in the grinding wheel dressing experiments. The experiments show that the dressing efficiency is the highest in mixed powder medium. The surface roughness of the workpiece obtained by the grinding wheel dressed in mixed powder medium is the smallest.