Abstract
Influence of hydraulic counter pressure forming and teflon (polytetrafuluoroethylene) lubricant forming on the cylindrical deep drawability of various aluminum alloy sheets is investigated. 8 type of aluminum alloy sheets (Al–Mg, Al–Mg–Cu, Al–Mg–Si and Al–Mg–Si–Cu) and a cold rolled steel sheet (SPCC, commercial quality) are used for testing materials. In conventional forming, aluminum alloy sheet with thin Fe–Zn coat shows maximum LDR (limiting drawing ratio) same as LDR of SPCC. In hydraulic counter pressure forming and conventional forming, LDR increases corelatively with surface roughness. In case of large surface roughness materials, LDR of hydraulic counter pressure forming becomes largest, 2'nd is that of teflon lubricant forming and 3'rd is that of conventional forming. However at small surface roughness material, such as bright sheet, LDR of teflon lubricant forming becomes largest. In cylindrical deep drawing of aluminum alloy sheets, with hydraulic counter pressure forming, large surface roughness and thin surface coat are very effective.
