Research On Electrode Design And Feeding Trajectory Of Closed Interal Turbine Blade

The development of aerospace technology has led to higher requirements for aircraft engine performance.As a critical component of the aircraft engine,the reliability and efficiency of turbine blisk are very important.However,the shape of the blade is complex,channels are narrow and twisted,and the material of the blisk is high-performance materials.Using the traditional machining method is easy to make the tool and the blisk occur interference and the precision is low.So,the processing of the integral blisk becomes a problem.Electrical discharge machining(EDM)is suitable for machining integral turbine blisk because the tool is not in contact with the workpiece and EDM can process workpiece by copying.The keys of EDM are electrode design,electrode feeding path searching,and process.To solve the problems,this thesis proposes a feeding path searching method based on other researches,investigates the relationship between processing parameters and the machining effect,and studies the process of closed integral turbine blisk.Aiming at electrode feeding path searching,a method of path searching is proposed based on other researches.The shaped electrode is designed by splitting and reducing.The constraint conditions and calculation method of the distance from electrode surface to blisk surface are optimized.The optimal attitude of electrode is found by combining the simulated annealing algorithm and particle swarm optimization,and then the feeding path is obtained.The simulation results show that electrode can feed smoothly in the center of the channel along the path which is obtained by this method.Next,the relationship between processing parameters and processing results are investigated.Through single factor influence experiments and orthogonal experiments of processing parameters,the effects of pulse width,pulse interval,peak current,type of processing medium,and polarity of electrode on processing efficiency,workpiece surface quality and electrode wear are researched.Finally,the process of closed integral turbine blisk is researched.The modification of four-axis EDM machine to six-axis EDM machine is explored.The process and the processing parameters of the closed integral turbine blisk are studied.The machining errors which are produced in the actual process are analyzed,and methods of reducing these errors are proposed.The processing of the closed integral turbine blisk is completed.