Characteristics of aerosol produced by an internal-mix nozzle and its influence on force, residual stress and surface finish in SQCL grinding

A tiny amount of cutting fluid is atomised and consumed at a very low rate in SQCL (small quantity cooling lubrication) grinding process and delivered in grinding zone. Grindability is significantly influenced by aerosol characteristics. In the present work, CFD (computational fluid dynamics) based modelling of the aerosol (air atomised water) produced by an internal-mix nozzle was carried out and validated. Various parameters, which are significantly pertinent to grindability, like droplet diameter, droplet velocity and heat transfer coefficient, were in the focus of the study. The model suggests that the SQCL technology can be effectively used at comparatively high atomising pressure with reduced flow rate for achieving adequate level of heat transfer coefficient. It was further concluded that higher flow rates or atomising pressure increases the wettable area, helping in reduction of the grinding zone temperature. Intensity of the tensile residual stress and tangential grinding force were found to be reduced in both cases but the former one was more sensitively influenced by increase in atomising pressure.