Temperature Field Of Nickel-based Superalloy Blade Teeth Produced In Creep Feed Deep Profile Grinding

Nickel-based superalloy rotating turbine blades are the important components of aero-engine.Creep feed deep profile grinding plays a vital role in advanced manufacturing of turbine blade teeth in the present days.However,due to the bubble nucleation boiling and the film boiling effect of the coolant in grinding arc region,creep feed deep grinding encounters the following problems,that is,the surface temperature of the workpiece can be effectively controlled bellow 130? in the normal grinding process.,but it suddenly rises largely and causes the ground workpiece burn.Due to the lack of the effective method in prediction of creep feed deep grinding temperature,the related basic data and theory are inefficient to design the process from grinding roughcast to finishing parts.It is difficult to achieve the aim to effectively control burn in creep feed deep grinding.Therefore,it is proposed to investigate the temperature field in creep feed deep profile grinding of GH4169 nickel-based superalloy blade teeth in the current work.Firstly,the temperature evolution and the effect of blade profile on temperature distribution during grinding process have been evaluated based on finite element simulation.Then,grinding tests have been conducted to verify the simulated results.Finally,the grinding parameters were optimized and the prediction and control of grinding burn were achieved to a certain extent,which contributes to realizing the high efficiency and precision machining of turbine blade teeth.The main work and achievements are as follows:(1)The experiment of creep feed deep grinding of GH4169 nickel-based alloy blade teeth was carried out with brown corundum abrasive wheel.The grinding force and grinding temperature were measured.An empirical formula of tangential grinding force,including grinding parameters and total grinding depth,was established.Results indicate that,the grinding temperature at blade top teeth is higher than the blade root temperature,and almost all top teeth of blade have the same temperature value.(2)Comparative analysis suggested that the triangular moving heat source model is more suitable than the rectangular moving heat source model for simulating the temperature field of nickel-based superalloy blade teeth produced in creep feed deep profile grinding.Based on this,the simulation model of the temperature field of blade teeth produced in creep feed deep profile grinding was established.Through the comparison between simulation and experiment,the empirical formula of the cooling coefficient of the grinding fluid in the arc zone under different grinding conditions was obtained.(3)The accuracy of the simulation model of the grinding temperature field of blade teeth produced in creep feed deep profile grinding was confirmed based on experimental results.The temperature distribution and evolution of blade teeth in the process of creep feed deep profile grinding were explored.It was found that the top of the teeth is usually the highest grinding temperature area,where the grinding burn could happen easily.Accordingly,the combined grinding parameters of the blade teeth from roughcast to forming were optimized,and the grinding efficiency was improved.The surface integrity of finished blade teeth was evaluated when using the optimum parameters,and the obtained surfaces were found with free defects.