Numerical Simulation Of Temperature Fields And Flow Field Of Friction Stir Welding

Friction stir welding is a green solid-phase welding technology.It has a huge advantage in the light metal joining process.Its development in the history of welding technology is a miracle.The time span from invention to application is short and the development is quick.As a new green welding technology,it has been widely used in various fields such as aircraft manufacturing,new energy-saving automobiles,shipbuilding industry,high-speed trains,and aerospace.The process of the friction stir welding is a complicated process of the complicated nonlinear changes of the coupling of the multi physical field.,there will be the plastic flow of metal,the organizational structure change,the complex strain and temperature changes in the process of the friction stir welding and so on.It has a very important significance to optimize the process parameters of the friction stir welding and know the friction stir welding process and the forming mechanism of weld that mastering the temperature field and the change of friction stir welding process flow field mechanism.Therefore,the finite element software was used to simulate the temperature field changes of the friction stir welding and the welding parameters of the process parameters on the friction stir welding.After summarizing the research of friction stir welding of foreign scholars,this paper takes A6061 aluminum alloy plate as the research object,according to the specific physical properties of A6061 aluminum alloy and the actual theoretical knowledge of the welding process,based on ABAQUS finite element software to establish three-dimensional friction stir Welding thermo-mechanical coupling model,using ALEQ adaptive grid technology provided by ABAQUS and suitable boundary conditions,solved the problem of grid distortion caused by nonlinearity in the welding process..Based on the established A6061 finite element model,the temperature field of the friction stir welding process was numerically simulated.The preheating phase and the stablewelding phase in the welding process were studied separately.In the 3D model analysis,the axial press force is controlled to provide the required axial pressure.In the preheating phase,the variation of the temperature cloud diagram of different thicknesses of the plate is studied,and the heat flow mechanism along the thickness direction of the friction stir welding is analyzed.At the same time,a single variable method is used in the preheating phase to study different preloading times and different rotation speeds for the preheating time.Impact.It provides a theoretical basis for the selection of process parameters for friction stir welding.In the steady welding stage,temperature changes along the direction of the weld seam and in the direction of the vertical weld seam were studied.Changes in the temperature gradient along the distance from the center of the weld were analyzed,and the different temperature changes at the forward and backward sides of the stable weld stage were analyzed.In addition,this paper also introduced the relevant theoretical knowledge about friction stir welding flow model,and provided theoretical support for further research on the flow field of friction stir welding.