Research On Forming Process Of Sheet Warm Deep Drawing With Counter Pressure

Hydro-mechanical deep drawing is an advanced processing technology in thefield of sheet metal forming, which can improve the forming limit and part surfacequality, have simple mold structure, etc. This technology is already widely used inaerospace, aviation, automotive and other fields. However, the process itself has someinsurmountable disadvantages such as temperature limits, and thus to some extent,limit the range of applications of the hydro-mechanical deep drawing technology. Thesolid granular media forming is a soft tool forming technology that is proposed inrecent years. It uses solid granular media instead of conventional rigid punch or the die,to form the metal pipe or sheet. It has the advantages of easy sealing, good thermalstability, and environment friendly. This research is to combine the advantages of thehydro-mechanical deep drawing and solid granular media forming, and proposes a newtechnology called sheet warm deep drawing with back pressure. In order to improvethe ductility of aluminum alloy, the flange of sheet is heated. Solid granular media isused instead of the liquid medium in the hydro-mechanical deep drawing, to overcomethe shortcomings that the liquid medium that cannot withstand high temperature.In this paper,5A06aluminum alloy sheet is researched, to form typical cylindricalparts. Using finite element simulation software ABAQUS for numerical simulation, theprocess of sheet warm deep drawing with back pressure is studied. Changing differenttemperature, back pressure, blank holder force and other process parameters, the law ofprocess parameters on sheet metal forming properties is studied. The results show thatthe increase in temperature can significantly improve the sheet formability. However,formability of the sheet begins to decline in more than300℃.The device of sheet warm deep drawing with counter pressure was designed andmade. The device includes drawing systems, heating systems, cooling systems andcounter-pressure system. In addition to the traditional drawing features, it can alsoachieve the function of active controlling on granular media pressure and uniformheating of the sheet metal flange.Three experimental programs was designed, that is sheet inflation with granularmedia pressure, sheet warm deep drawing, and sheet warm deep drawing with counterpressure. The effect of granular media pressure on the sheet is studied through the experiments of sheet inflation with granular media pressure. The temperature effect onthe sheet is studied through the experiments of sheet warm deep drawing. Thecomprehensive effect on the sheet is studied through the experiments of sheet warmdeep drawing with back pressure. In the end, typical samples are formed to studysample thickness distribution, which is to examine the formability, and draw the bestcombinations of process parameters.