Dressing tools are used to regenerate and prepare the macro and micro geometry of a grinding wheel in order to compensate for the tool wear. Electroplated diamond dressing wheels can be categorized as positive or negative depending on their production process. On positive electroplated tools, the abrasive grains are positioned on the surface of the wheel body and fixated through electroplating. Because of the irregular shapes and sizes of abrasive grains, the profile of such produced tools is quite rough, as represented schematically here under.
Only through subsequent processing, namely dressing, the tool achieves the desired precision and roughness. Dressing is a time consuming grinding process, where diamonds are ground against diamonds for many hours depending on grain size, geometry and tolerance specifications. By using PLA, the ablation can be controlled without any significant heat affected zone (HAZ) on the workpiece.
For negative electroplated tools however, the diamonds are electroplated in a high precision negative mould. The wheel’s body is inserted and the mould removed. Tools produced in such a way exhibit a highly precise profile and do not need any subsequent processing such as dressing. The dressing process, however, not only defines the profile of the tool but also defines its machining properties by influencing the peak bearing area of the tool. PLA offers the possibility to influence the peak bearing area of negative electroplated tools, by structuring the tools with defined micro-grooves. Grinding forces can thereby be lowered and the chip and coolant flow improved. During the DIPLAT project, geometrically defined microstructures, 90 μm deep and 300 μm wide, were ablated on the surface of a negative electroplated tool . Benchmarking of the structured tool showed a clear beneficial reduction of processing forces thanks to the laser ablated grooves.