A New Sheet Metal Forming Technology Of Solid Granule Medium Deep Process Drawing

This paper proposes a new sheet metal deep drawing process , assisted with the original liquid medium,which replaces the solid granulas to the pressure transmission medium of hydromechanical deep drawing (liquid or viscous medium). The important difference between the new technology and hydromechanical deep drawing process is that the change of pressure transmission medium makes the forming rules of the sheet metal also change. Making analysis to cylindrical pieces of the solid granules deep drawing with plastic mechanics knowledge and finite element simulation , this paper obtaines various parts'stress and strain distribution rules. Theoretical analysis and finite element numerical simulation results show that the more pressure solid granules on the sheet, the smaller the axial tensile stress cylinder wall carrying , and the more dangerous to the cylinder wall's bottom of the face direction,the more obvious the stress decreases. It has played an inhibition effect of tube wall thinning and weakens the risk of cross-section's possibility of rupture, which can improve the forming limit of sheet metal.During the research process, cylindrical cup deep drawing test has been completed with the self– designed solid particles medium deep drawing die set. By changing various process parameters,it obtains a great deal of test data. Results show that the new technology of solid granules deep drawing compares to rigid mold deep drawing process can clearly increases the tensile limit of sheet metal and the thickness of the workpiece distributes more evenly. The less diameter of the granules are helpful to sheet metal forming,and the thickness distribution is more equality. To sheet LY12M with 1.0mm thickness,the test successfully produce the specimen with the limit drawing coefficient of 0.510.Experimental and theoretical analysis of forming process and finite element numerical simulation results are in good agreement. The new technology has good practical application value, it provides a new way to slove the low plasticity, hard deformation of the sheet metal forming.