Study And Analysis Of Teflon Utilization In Micro Sheet Hydroforming

The demand of various industries of micro-miniature modern technology to find new solution methods in a highly efficient mass production for a variety of micro-part is increasing.Hydroforming has a great potential to be used in mass production.Problems that occur in the field of the process production of micro sheet is when the sizes of materials is reduced at sub millimeter range,grain size have a major effect on material properties,plastic deformation,and the overall process the establishment.The size effect causes formability of micro sheet to be poor.To improve the formability of micro sheet,new methods are needed.In this project,a new method is presented,namely the use of Teflon to help improve the formability of micro sheet.This paper discusses the basics of the sheet hydroforming system,detects the Teflon material properties,and explains the process of micro sheet hydroforming with Teflon material in improving the micro sheet formability.For the experiment,micro sheet hydroforming with single pressure is used.Teflon material is used in the formation process.Free bulge test is done to investigate the size effect and influence of Teflon sheet on the formability of SS304 micro-sheet metal.Research results reveal that:l)the flow stress increases with the thickness of the SS304 micro sheets;2)the elongation of material sheet decreases with thickness weakening;3)the use of Teflon material can increase the crack pressure of the micro sheet.In other words,it shows that Teflon material has positive effect on micro sheet formability.Teflon can generate higher bulge levels and also reduce the thinning rate of the thickness compared to the conventional micro sheet hydroforming.Subsequently,Finite Element Method was used to simulate the Teflon assisted bulging processes of the micro sheet.To validate the prediction obtained from the simulation,a number of micro sheet hydroforming experiments were conducted.