Characterization of the Interaction of Metalworking Fluids with Grinding Wheels

The thermal load that occurs during grinding can be reduced with the aid of an optimized metalworking fluid (MWF) supply. In previous work, mainly the free jet was considered for the determination of the conditions required for an optimized MWF supply. An investigation of the interaction area between the MWF and the grinding wheel has not yet been carried out due to the lack of suitable measurement techniques. In the presented work, both the free jet and the interaction area are analyzed with the aid of new metrological analysis and evaluation methods based on high-speed records (shadowgraphy and shadogram imaging velocimetry) in order to assess the free jet geometry and velocities, as well as the velocity distribution and the MWF amount in the interaction area. Using this approach, the following main results were derived: (1) The free jet velocity remains approximately constant in a defined free jet cross-section even at high distances from the nozzle outlet. (2) The velocity distribution in the interaction area is mainly influenced by the flow rate. (3) A new image parameter (black pixel fraction) was derived for the evaluation of the MWF supply to the contact zone.