Research On Creep Age Forming Of Aluminium Alloy Friction Stir Welding Components

The creep age forming is one of the important metallic forming process for largeairplane. The integral panels or ribbed plates are important structures of airplaneaerofoil and fuselage. At present，the processing of panels are highly dependent on thecomputerized numerical control (CNC) cutting machine tools， which is a newhigh-speed and efficient method. Accordingly, the processing cost is very high、theprocessing cycle is very long and the material utilization rate is very low.In the field of welding，the friction stir welding (FSW) is a new technique，whichcan achieve excellent welding joints、has distinct advantage for aluminium ally weldingstructures and shows good application in the aerospace manufacturing industry.Therefore，the study on the creep age forming of integral panel structures based on FSWprovides a new and low-cost method for ribbed plates and has important value in theengineering application.First of all，the work fixture and stir head of T-tipe FSW are designed andmanufactured for the ribbed plates，then the ribbed plate weldments of2A12areachieved by FSW，and the optimal welded parameters of FSW are obtained by thecomparative analysis of the welded joints with the different mechanical property andmicrostructure. When the welded joints have been treated by different heat treatments，then its comprehensive performance produced different change，especially the treatmentof annealing+solid solution+aging or step aging can greatly raise the tensile strengthand hardness of welded joints，and improve the microstructure of weld bead.Secondly，the optimal parameters of the2A12aluminum creep age forming areobtained by the machine loading mould，the aging temperature is190℃，the aging timeis10h. Then，the creep age forming of ribbed plates are tested by the air-pressureloading mould and the effects of creep age forming temperature and time on the formingquality of ribbed plates are researched under certain conditions.Finally，the paramenters of2A12aluminium alloy in the creeping constitutiveequation are obtained by the high-temperature electronic creep tensile test. Based on thefinite element (FE) software ABAQUS，the FE model of creep age forming has been setup. And then，the effect of creep age forming time、radius of die、height of ribbed bar、 width of ribbed bar、thickness of sheet on the forming quality of ribbed plates areresearched and analyzed. At the same time，the model of creep age forming is verified tobe better to reflect the forming process of the ribbed plates.In the paper，by the methods of FSW and heat treatment, obtain the ribbed plateswelding structure with good property；The creep age forming process of ribbed plateshas been analysised by the air-pressure loading mould and FE technique，which showreference value in the engineer application.