Abstract: Electrical discharge dressing (EDD) process is a non-traditional promising truing and dressing technology for superabrasive wheels. The process makes use of electrical energy to melt and vaporize the wheel bond, and make the abrasive grains stick from the grinding wheel. The development of lightning leader displays a stochastic discharge channel with branching and tortuous structure during EDD. It obviously has characteristic of self-similarity, which can be well described by fractals. A discharge channels simulation model based on the fractal theory shows the thermal energy distribution of various discharge mediums on the diamond wheel. And various discharge mediums including kerosene-based oil,impressed air and misted deionized water, are applied on EDD bronze-bonded diamond grinding wheels. The surface topography of dressed diamond grinding wheel is observed by VHX-1000 three-dimensional digital microscope. The analyses indicate that the surface topography of dressed diamond grinding wheel is consistent with the feature of simulation discharge channel based on the fractal theory. At the same time, the fractal simulation model of discharge channels is benefit to predict the wheel dressing microstructure and fressing quality.

Key words: machinofacture technique and equipment, fractal theory, discharge mediums, dressing, diamond wheel