Experimental studies of heat dissipation by a stream of dressing products during dry dressing of conventional ceramic grinding wheels

Part of the energy required to perform the dressing process is converted into heat, which is generated by friction and elastic-plastic deformations occurring in the contact area of diamond grit and the grinding wheel. This heat is diffused by thermal conduction in the direction of the grinding wheel and the body of the dresser, electromagnetic radiation, convection and it is also transferred through the particle stream of dressing products. This article describes the assessment method and the results of the research on the amount of heat accumulated in the stream of the particles of the dressing products. In the presented method, the enthalpy of the stream was estimated based on the measurements of electrical voltage generated by the Peltier module set in a short distance from the point of stream formation, transversely to the direction of its movement. The method of determining the thermal-voltage characteristics of the module necessary to determine the amount of heat released by the particle stream is described. The research of enthalpy streams was carried out during dry dressing of conventional ceramic grinding wheels made of brown and white fused aluminum oxide and green silicon carbide. Dressing studies were performed with a single point diamond dresser using various feed values and dressing depths. Measurements of the Peltier module voltage were carried out simultaneously with measurements of the diamond grain temperature in the dresser and the power of dressing. On the basis of the obtained results, the correlation of the module voltage signals and the diamond temperature is evaluated. Furthermore the influence of dressing parameters and type of grinding wheel abrasive material on the magnitude of stream enthalpy and its share in dressing energy are also evaluated. The studies show that the module voltage remains in almost full, linear correlation (ρ > 0.95) with the diamond dresser temperature; the amount of heat carried by the stream constitutes a few percentage points (2%-5%) part of the dressing energy, and the amount of this share increases with the increase of the thermal conductivity of the grinding wheel material and dressing volume capacity.