Research On The Evolution Law Of Temperature Field Of Friction Push Plug Welding

Friction push plug welding is a solid-state welding technology,and it is widely used in aerospace,automotive and other fields with its characteristics of energy-saving,environmental protection and good mechanical properties of repair welding joints.To explore the influence of process parameters on the quality of welded joints,the research is mainly conducted in the way of test,and the welding parameters are finally optimized.The distribution of temperature field is studied by the finite element numerical simulation and test,and this paper analyzes the influence of process parameters on the temperature field.The welding joint quality is closely related to temperature field,which is finally verified by the distribution feature of welding joint.The main work is summarized as follows:(1)The friction push plug welding process is divided into three stages,and heat model in different stages are derived by the mathematical theory method,which provides a theoretical basis for the finite element numerical simulation of temperature field.(2)The cloud map of the distribution of temperature field for 7075-T6 aluminum alloy in the process of friction push plug welding is obtained by simulation.The results show that the rising rate of temperature at initial stage is highest,and temperature field distribution has appeared with the highest temperature at the interface and lower temperature far away from the interface;the temperature difference is very small at different height of the friction interface.(3)The test of friction push plug welding process for 7075-T6 aluminum alloy has been carried out,which verifies the reliability of finite element model of temperature field.The influence of process parameters on the temperature field is analyzed,the result shows that the larger welding speed and welding pressure can improve the rising rate of temperature at initial stage,and friction time mainly affects the highest temperature of aluminum plate in the process of welding.(4)The microstructure and microhardness of the welded joint has been tested,the influence on the different areas of the microstructure form is briefly analyzed by the welding temperature and mechanical load.The influence of welding parameters on the tensile strength of the joint is analyzed,and it is shown that the temperature field is the main influencing factor of the joint strength.