| The invention of friction stir welding(FSW)welding technology has a history of more than 20 years.Many scholars have been engaged in the research and application of this technology for many years,and have achieved a lot of scientific research results,but for The complete mastery and wide application of friction stir welding technology requires further research.Therefore,the welding process of aluminum alloy material is studied by friction stir welding technology.The mechanical properties and microstructure of the welded sample are tested and analyzed.Therefore,it is important to accurately and comprehensively grasp the weld quality of FSW welding of aluminum alloy materials,which is of great significance for the improvement of friction stir welding technology.Mainly carried out the following aspects of research:Firstly,the research mechanism of friction stir welding technology was analyzed.Through the literature review,theoretical analysis and scientific reasoning,the welding principle,elastoplastic deformation process and friction heating principle of friction stir welding technology are analyzed and analyzed.The transient heat transfer characteristics of friction heating are analyzed.Since the friction stir welding process is a heat and heat transfer process combined with heat engine,the article also analyzes the heat generation mechanism and heat conduction mechanism with certain elastoplastic deformation under the solid temperature point characteristics,and proposes the corresponding analysis model.Secondly,using ABAQUS simulation analysis software to simulate the welding process,the temperature field of FSW after welding and the variation of plastic strain value were simulated,and the welds caused by frictional heat during welding were explored.Changes in temperature and plastic strain values in the area.The simulation found that during the FSW welding process,the area with the highest temperature appeared near the stirring needle,and the temperature at the edge of the remaining shoulder was lower than the melting point of the base material,which was about 80% of the melting point of the base material.At the same time,it was found that the temperature distribution in the weld zone was symmetrical along the center of the weld,but the mixing head was asymmetrical before and after.And the plastic strain value has a stirring head shoulder from the inside to the outside value increases.Thirdly,the welding test was carried out on the most used 2000 series and 6000 series aluminum alloy materials in the industry.The Instron-5982 electronic universal testing machine and Wilson-hardness tester provided by the school were used to pull the welded samples.The mechanical properties such as tensile strength,elongation and hardness were analyzed.It was found that the fractured regions occurred in the affected area of the heat engine,and compared with the mechanical properties of the base metal,it was found that the welded samples were obtained under the superior welding process.80% mechanical properties of the material.In order to further explore the weld quality,the microstructure of the material was analyzed and studied by X-ray diffraction(XRD),scanning electron microscopy(SEM),EDS and EBSD materials microscopic test analysis equipment,and the metal formed during the welding process was found.The inter-compound(Al2Cu strengthening phase)has a great influence on the weld quality,and different texture structures have different degrees of influence. |
