Numerical Simulation of Airflow Field in Grinding
With a view to find better ways for coolant delivery, the boundary layer of peripheral air of grinding wheel is simulated using finite volume method. By means of introducing Sparlart-Allmaras (SA) model into the mathematical model, the airflow field is calculated and pressure distributions and velocity distributions are obtained by simulations. An experiment is run to testify solutions of numerical simulation accordingly. The simulation solutions are in consistent with the experiment results on the whole. Therefore, this simulation method holds true for predicting the performances of airflow field around grinding wheel when grinding wheel rotates at high speeds. Based on the numerical solution results obtained in this paper, the causes to disadvantage of coolant delivery into the grinding zone are studied from the point of view of the pressure and velocity. In the end, one optimizing way of coolant delivery is specified and a few useful conclusions are drawn for applications of coolant delivery in the course of high speed grinding. Methods and conclusions of this research are available for perfection of grinding theory and applications of cooling in the future.
Friction, Cooling and Lubrication in Grinding
Abstract It is generally considered that the heat produced during the grinding process is critical in terms of workpiece quality. Relatively high friction effects in abrasive machining cause heat generation which can lead to thermal damage in the surface layer of a machined part; cooling and lubrication therefore play a decisive role during grinding. The keynote paper shows the effect of coolant type, coolant composition and coolant supply on grinding processes and process results. Further investigations in the fields of fluid dynamic processes in supply nozzles and in the grinding zone are the key to optimization of cooling and lubrication during grinding, thus offering the chance to minimize the amount of coolant in circulation, leading to a reduction of adverse environmental effects and cost.
SR topography of plastically deformed Fe-Si bicrystals - observation in situ and post mortem
SR reflection topography was applied to study the interaction of slip dislocations with the grain boundaries in Fe-4at%Si bicrystals deformed by compression. Three experimental settings with either a white or monochromatic beam were used and the corresponding orientation contrast analysed. Dislocation transmission through the grain boundary was observed in bicrystals with favourable geometry of the slip systems.