Intelligent Prediction Of Physical Quantities And Mechanical Properties Of Joints In 2219 Aluminum Alloy Thick Plate FSW

2219 aluminum alloy is a high-strength aluminum alloy with low density,high corrosion resistance and excellent processability,which is widely used in heavy-duty launch vehicle fuel tanks.Tanks are usually welded by welding.Conventional welding is easy to cause defects such as holes,cracks or lack of penetration in the welding area of 2219 aluminum alloy.Friction stir welding(FSW)has become the first choice for 2219 aluminum alloy welding due to its advantages of no pollution,no smoke,no radiation,high welding efficiency,small deformation of the product after welding,and excellent mechanical properties of the welded seam after welding.When the thickness of 2219 aluminum alloy increases,the welding heat input increases,which directly affects the temperature distribution in the welding area,resulting in a large temperature difference between the upper and lower sides and the dissolution of the strengthening phase.The microstructure and properties of the weld are different along the thickness direction,so it is difficult to ensure the tensile strength of the weldment,and thus it is difficult to ensure the welding quality.The welding process parameters affect the welding temperature field and welding force,and the welding temperature field and welding force directly affect the welding strength.However,the influence law of FSW welding process parameters on process physical quantities and process physical quantities on post-weld mechanical properties of 2219 aluminum alloy thick plate is unknown.Therefore,based on experiments,this paper studies the temperature,upsetting force and post-weld mechanical properties prediction of 18 mm thick 2219-T8 aluminum alloy friction stir welding,and develops a FSW temperature and tensile strength prediction system.The specific research contents are as follows:First,the FSW experiments of 2219-T8 aluminum alloy thick plate is carried out,and a large number of process parameters,welding temperature,welding force and post-weld tensile strength data are obtained.Then,a neural network-based model of the relationship between aluminum alloy welding process parameters,temperature,and upsetting force is established,and the prediction of peak temperature,temperature on the advancing side and retreating side,and upsetting force is achieved.Based on neural network,the relationship model between welding temperature,upsetting force and tensile strength of 2219-T8 aluminum alloy is established,and the internal relationship between welding temperature,upsetting force and tensile strength is explored.The effects of process parameters and temperature distribution on the mechanical properties of welded joints are revealed.Finally,based on Java language and My SQL database,a friction stir welding information query database is built,which realizes the functions of adding,deleting,modifying and viewing welding data.Based on the established welding information query database and the neural network-based model of the relationship between welding process parameters and physical quantities in the welding process,as well as the relationship between process physical quantities and post-weld mechanical properties,a prediction system for friction stir welding temperature and tensile strength is developed.It can realize the prediction of temperature and tensile strength of 2219 aluminum alloy thick plate FSW welding area.This paper studies and explores the influence law of 2219 aluminum alloy thick plate FSW welding process parameters on process physical quantities and process physical quantities on mechanical properties after welding.It can realize the prediction of welding temperature and tensile strength of 2219 aluminum alloy friction stir welding.The research results can provide support for the process control of friction stir welding of thick plate 2219-T8 aluminum alloy,and provide a reference for high-quality welding of heavy-duty rocket fuel tank FSW.