Research On Superplastic Forming Process Of 5083 Aluminium Alloy Covers For Rail Transit

With the vigorous development of China's rail transit industry and the global environmental pollution and energy shortage,it is urgent for China to develop manufacturing technology to make rail transit train components by using lightweight aluminum alloy.Superplastic forming process can improve the material deformation capacity significantly,and achieve the formation of complex shaped parts;Therefore,using superplastic forming process can produce lightweight,high strength,beautiful and environmental friendlly rail transit aluminum alloy components.So the superplastic forming process is very important for the sustainable development of rail transportation industry.In this paper,a superplastic forming process was developed by using the industrial model 5083 Al as the experimental material,and a mature superplastic forming process was developed.Finally,the superplastic forming process was conducted on door frame parts and ridge skin parts,and these forming parts are successfully used by the rail transit industry.In this paper,the superplastic deformation performance of 5083 Al under uniaxial stress was studied firstly.The results show that the superplasticity of 5083 Al was enhanced with the increased temperature.When the temperature was 500 ?,the superplasticity was the strongest,and the superplasticity of 5083 Al for rail transit was enhanced with the decreased strain rate.When the strain rate was 1×10-3s-1,the superplasticity was the strongest.In order to study the superplastic deformation behavior of the 5083 Al under complex stress conditions,the superplastic bulge of hemisphere,box and ridge test specimens were used,and the SEM,EDS,EBSD,XRD tests were conducted for this 5083 Al after superplastic bulging.The forming limit and wall thickness distribution of the 5083 Al for rail transit were studied by the bulging of a hemisphere.The height of standing wall of 5083 Al was studied by box shaped parts.The small rounded filling capacity of 5083 Al was studied by ridge shaped parts.The microstructure of the material after superplastic forming was studied by observing and detecting the microstructure of 5083 Al.The results show that when the control temperature was 460? to 480?,the packing pressure was 1.6 to 2.0MPa,which were the most favorable ranges for superplastic forming of the 5083 Al.In order to develop a fully applicable superplastic forming process,this paper has designed the dies of the door frame and the ridge skin parts by Catia v5,and made the finite element simulation of the superplastic forming process of these two parts by Marc software,and it optimized the die design and process plan;Finally,through the manufacture of dies and parts of the trial production,the process technology was improved,and successfully made trial parts with satisfactory quality.