Study On Ultrasonic Vibration Assisted Abrasive Belt Grinding And Polishing Of Titanium Alloy Blades

As a key component of engine,blade plays a decisive role in engine performance.Blade is normally made of difficult to machine materials such as TC4.It is a challenging task to ensure that high surface quality and dimensional accuracy of blade with complex geometry during machining process.The existing manufacturing process mainly adopts the method of combining high-precision milling with grinding wheel or belt grinding.However,there are some problems in abrasive belt polishing titanium alloy blades,such as difficult to guarantee the processing quality,easily burned,low material removal rate and so on.In order to solve the problems,ultrasonic vibration is added in conventional abrasive belt grinding to improve material removal rate and reduce grinding force.Based on the analysis of the research status of ultrasonic vibration assisted grinding,the theory of ultrasonic assisted abrasive belt grinding and polishing is studied.It is proposed that the loading direction of ultrasonic vibration is axial.On this basis,the axial loading mode of ultrasonic vibration is designed,and the corresponding abrasive belt grinding and polishing device is developed for basic verification experiment.(1)Firstly,the Hertz contact model is used to establish the contact model between belt and workpiece.The movement track of single abrasive under ultrasonic vibration is established,and the material removal volume of single abrasive under micro angle is obtained by matching with the contact model.The grinding force model is obtained by using the relationship between the material removal volume and macro material removal volume.The grinding process is simplified as the grinding process of a single abrasive,and the grinding simulation model of a single abrasive is established.Through the simulation,the influence trend of various grinding parameters on grinding force and grinding temperature is obtained,which lays the foundation for subsequent experiments and verification.(2)A machining system for ultrasonic vibration assisted abrasive belt polishing is designed and built,and the six axis manipulator is used as the main body of motion control.The design,check and integration debugging of ultrasonic assisted open abrasive belt device are mainly carried out.The transmission mode of axial vibration is designed,and the horn and the vibration transfer rod are calculated,and the impedance matching calculation is carried out to get a more accurate size of the vibrating rod.(3)The basic experimental verification of different process parameters is carried out on the built machining system,and the experimental design of grinding performance is completed.Through the orthogonal experiment,the influence of different process parameters on the processing effect is analyzed,and the validity of the theoretical model and simulation is verified.The measurement system of grinding force,temperature,surface quality and material removal rate in the grinding and polishing process is developed,and the optimal process parameters are obtained by grey correlation analysis.