Development And Grinding Performance Of A Pressurized Internal Cooling Grinding Wheel Based On Arc Flow Channel

Nickel-based superalloy has been widely utilized in the aerospace industry for its outstanding performances,including high strength,heat resistance,and fatigue resistance,etc.However,due to the poor thermal conductivity of the material in the grinding process,grinding heat is accumulated easily in the grinding zone to result in grinding burn and the fast wear of grinding wheel,which greatly reduce the grinding efficiency and the grinding quality.Traditionally,coolant is poured into grinding zone in the grinding area as much as possible to ensure the forced cooling.With the increase of grinding velocity,an air barrier effect is easy to form in the surrounding of grinding wheel,which causes a poor cooling effect.Therefore,it is of great theoretical significance and practical value to develop efficient cooling technology.In this paper,based on the pressurized internal-cooling technology,intermittent grinding technology and the effect of centrifugal force,a slotted grinding wheel with pressurized internal-cooling system in surface grinding was prepared.Moreover,the arc channel was designed to ensure the rapid cooling effect with large outlet velocity in the grinding contact zone.The main contents of this paper were briefly described as follows:(1)Based on the working principle of pressurized internal-cooling grinding wheel,the structure of internal flow channel was designed.The curve equation of arc channel was established,and the arc flow channel was arranged reasonably,then the basic dimensions of the pressurized internal cooling grinding wheel were determined.The flow characteristics of inner fluid were compared with the linear channel and the arc channel in the grinding wheel.The machining drawings of the grinding wheel matrix were drawn,and the whole assembly model of the grinding wheel was set up.(2)The internal field model of the grinding wheel was established.The pressure distribution and the velocity distribution were simulated by ANSYS Fluent.The main structural parameters which affect the flow characteristics were optimized,such as the opening angle and the diameter of the flow channel.The sealing performance and the structure of pressurized internal-cooling grinding wheel were verified based on 3D printing technology.(3)Based on the heat source method,the temperature field model in surfacegrinding was build.The heat transfer when grinding was analyzed.The variation trend of heat flux,coolant pressure and wheel velocity on grinding temperature were studied.And the influence of the linear channel and the arc channel on grinding temperature was compared under the different heat flux.(4)The grinding wheel body and fixture were prepared,and the kinds of abrasive particles and the preparation technology were selected reasonably.The spray experiments study of grinding wheel was carried out to analyze the injection effect of coolant with the linear channel and arc channel under the same coolant pressure.Grinding experiments for nickel-based superalloy with different channels were carried out under the same grinding parameters.The influence of coolant pressure on grinding force,grinding temperature,surface roughness and surface topography were studied.Finally,the experiment data and the simulation results were compared,and the correctness of the three-dimensional temperature field model was verified by analyzing the grinding temperature under different heat flux.