Development of environmentally friendly fluid for CBN grinding

Environmentally friendly water based fluids have been offered recently by many suppliers. On the other hand the G ratio values obtained for CBN grinding with water based coolants are much lower than with neat oil. This work presents a new water based grinding fluid formulation able to meet both the performance and environmental requirements for CBN grinding. The existence of a reaction between CBN grains and water is evaluated in grinding tests and also in a chemical reactor. The results show that the reaction between CBN grains and water is not significant when compared to the measured volumetric wheel wear in a grinding operation. Based on this fact, a new fluid concept consisting of a high concentration (up to 40%) of sulfonate vegetable oil in water is proposed and tested. In this way it was possible to combine high lubricity, better heat conductivity and good environmental properties in one fluid. The results show performance comparable to the obtained with neat oil.