Study On Temperature Control System Of Laser Cladding Pool

Laser cladding technology is a high-tech technology that uses high-energy and high-density laser beams to inject into the metal matrix to form a molten pool,realizing the combination of metal matrix and cladding materials,and forming a cladding layer with wear resistance,high temperature resistance and corrosion resistance.The molten pool temperature is the main factor that affecting the forming quality of the cladding layer.And the change of the molten pool temperature will lead to the instability of the morphology and performance of the cladding layer.Moreover,the effectively control of the molten pool temperature is crucial to the shape control of laser cladding.Therefore,it is of great engineering significance to study the control system of laser cladding molten pool temperature and ensure the stability of molten pool temperature for improving the morphology and performance stability of laser cladding forming parts.This work takes the laser cladding forming system independently integrated by VMC850 E and IPG laser as the experimental platform.Then,a deeply analyze on the relationship between the process parameters and the molten pool temperature in the laser cladding process is conducted.Finally,the closed-loop control system of molten pool temperature based on incremental integral separation PID is developed.The specific research contents are as below:(1)To cope with the problem that a large number of affecting factors and complex influence relationship of the laser cladding layer morphology and the molten pool temperature.The single factor and orthogonal experiments is conducted to explore the influence law of process parameters such as laser power,scanning speed and powder feeding rate on the temperature of molten pool,which lays a foundation for the development of subsequent laser cladding molten pool temperature control system.(2)To solve the problem of poor forming quality caused by unstable molten pool temperature in laser cladding process,a molten pool temperature monitoring platform is constructed,and a closed-loop control method of molten pool temperature based on incremental integral separation PID is performed.The closed-loop control system of molten pool temperature is developed by Visual Studio C + +,in this way,the real-time control of molten pool temperature in laser cladding process is realized.(3)To verify the effectiveness and reliability of the molten pool temperature control system of laser cladding,the open-loop and closed-loop laser cladding experiments are designed to analyze the temperature gradient change of molten pool in the laser cladding process.The comparison experiments of thin-walled wall specimens in dimensional accuracy,microstructure and hardness are conducted.As a result,the effectiveness of the molten pool temperature control system is further verified.