Application And Research Of Superplastic Forming Technology In Railcars

The important direction of rail vehicle development in the world is high speed and light weight.The large thin wall aluminum alloy plates are used to manufacture interior components for subway,high speed trains and other rail vehicles,etc,including the side wall(with window),and end wall,door pillar,ceiling and other important components,which has the advantages of light weight,and beautiful appearance,fire retardant and anti graffiti,corrosion resistance and other excellent properties.First,by comparing several common aluminum alloy forming processes,rapid super plastic forming can be used as a new composite process to solve the problem of local complex shape and improve the forming efficiency by super plastic expansion.Secondly,three pieces of microcrystalline super plasticity and high temperature deformation behavior of aluminum alloy are introduced.The super plastic formability of aluminum alloy was introduced,and the high temperature material properties of the super plastic aluminum plate were introduced by comparing the variation of the elongation and deformation stress at different temperatures.Then,the thermal tensile test was carried out on the domestic 5083 aluminum alloy sheet,and the strain rate elongation rate and the load position of different strain rates at different temperatures were obtained.The true stress-true strain at different temperatures and the strain rate sensitivity index-the strain rate curve can be used to obtain the super plastic properties at different temperatures and strain rates,which provide a theoretical basis for the super plastic forming of materials.Finally,by using the finite element software MARC/ MENTAT to simulate the super plastic forming process of the parts,the order of the sheet and the change of the thickness of each part,the pressure time curve of the forming are seen,and the development of the super plastic equipment,the design of super plastic mould,the forming process and the forming process are made from the actual project.Product verification four aspects of super plastic forming project development process is studied.Through the analysis of the simulation results and the actual situation of the thickness distribution of the aluminum plate wall and the wall thickness of the hard forming area in the super plastic process,it is shown that the two have good consistency.And the actual correction of the original algorithm is more successful in predicting the whole development process of the aluminum alloy super plastic forming,which is a super plastic forming technique.The technology is widely applied in light aluminum alloy interior decoration products,providing accurate reference experience.