Experimental Study Of Laser Cladding Temperature Field And Cladding Trajectory Facing Slender Axis

The slender shaft is a part that is often encountered in the actual production and processing of the machinery industry,and is widely used in many fields.In order to improve the ability of shaft parts to cope with various working conditions,shaft workpieces are generally subjected to various surface treatments on shaft workpieces to improve the hardness,fatigue strength and other properties of the parts.As a new type of surface modification technology,laser cladding has received more and more attention and use,thanks to its high efficiency,environmental protection and other characteristics.It is regarded as a new way for traditional machining to move towards intelligent manufacturing.In this thesis,the slender shaft is taken as the research object,and the shaft parts are analyzed from the aspects of simulation and experiment,and the influence of different cladding trajectory methods on the surface coating quality is explored.Orthogonal experiments were designed,and the optimal combination of the three variable factors of laser power,powder feeding rate and scanning speed was obtained by using the range method analysis,which was used as the process parameter standard for subsequent research.The three-dimensional physical model is established with reference to the actual workpiece,the mesh is divided and the boundary conditions are set,and the simulation process of laser cladding is realized by combining the mobile heat source and the "life and death unit" technology.Explore the temperature field distribution law and thermal cycle characteristics,and collect the temperature change curve of the observation unit.In addition,a high-power fiber-coupled semiconductor laser was used to conduct cladding experiments on the slender shaft,and the cladding layer after metal sample preparation was observed by a testing instrument to compare and evaluate the reliability of the simulation results.The effect of laser cladding on the bending degree of the slender shaft was further investigated by simulation and experiment.This thesis draws the following research results:In this study,it is found that the slender shaft with a spiral path of laser cladding,the cladding layer on the surface effect is better,the single spiral lap coating surface roughness is higher,the coating internal microstructure grain close symmetry,put it at the bottom of the coating and substrate formation porosity is relatively much more small screw.The above research has a certain guiding significance for the work related to surface modification quality of slender shaft cladding trajectory.