Research On Key Technologies Of Laser Compound Turning And Milling

Laser-assisted machining is a kind of complex machining technology,which is used to improve the machining performance of materials,thus reducing tool wear,improving machining quality and efficiency.However,laser composite machining technology has not been mature process application in the production of high-performance parts.Beryllium is a key material for aerospace because of its low density,high melting point,high specific strength,high specific stiffness and excellent thermal physical properties.But its excellent material performance will also bring difficulties in processing and low production efficiency.Aiming at the problems existing in the research and practice of laser-assisted machining,this paper takes beryllium as the research object and studies the key technologies of laser-assisted turn-milling.In this paper,the following aspects of research:Firstly,based on the Hopkinson pressure bar device,the dynamic mechanical properties of beryllium were tested,and the stress-strain curves were obtained.The constitutive model of beryllium is constructed by finite element method.An inverse method was used to determine the laser absorption of beryllium during laser heating.Through the preheating test of beryllium material,the suitable laser power in preheating stage is determined.The cutting force experiment system of laser-assisted turning is set up,and the influence of cutting parameters and tool materials on cutting force is studied.Secondly,according to the theory of heat transfer,the 3D transient thermal model of laser heating aided cutting temperature field is established,and the influence of process parameters on laser spot temperature and cutting temperature is studied.The optimum temperature range of laser heating region is analyzed,which provides the parameter basis for cutting simulation.The simulation model of laser heating cutting of beryllium is established,the simulation value is compared with the cutting test value,and the suitable cutting parameters are determined.Thirdly,according to the basic theory of kinematics,the digital model of laser compound machining is established,and the kinematics analysis of synergetic manipulator and turn-milling compound machine is carried out.At the same time,the mapping relationship between the light spot of the cooperative manipulator and the workpiece is discussed,and the trajectory motion of the equipment under different machining modes is analyzed.The robot toolbox of MATLAB software is used to solve the problem,which provides a theoretical basis for parameter selection of dynamic simulation test.A finite element model of laser assisted cutting equipment is established.The first six natural frequencies and vibration modes of the laser assisted cutting equipment are obtained,and the weak part of the equipment is analyzed.Finally,the virtual system of laser-assisted machining is built,the motion relation of each axis is analyzed,and the motion track of each axis is simulated by dynamic simulation.A special machine tool for laser assisted cutting is used in the experiment.The virtual system is compared with the experimental system synchronously.The validity of the virtual simulation system is verified.