Investigation of Micro/Milli Flexible Deep Drawing Process

Flexible forming technology provides significant application potential in the manufacturing of complex shaped components even at miniaturized levels. The most attractive characteristic of this technology is simplicity, and its feasibility for prototype processes and low-volume production. The main purpose of this study is to clarify the decisive characteristics of micro deep drawing of metallic foils by using flexible forming technology. In this work a new technique is adopted using rigid punch, rigid holder and rubber pad, so that a particular gap is allocated between the blank holder and a fixed plate to allow the rubber pad to expand through it. The key process parameters studied here are rubber hardness, rubber-pad dimensions, drawing velocity, and initial gap value. Stainless steel 304 foils are used with thickness of 0.1mm. To investigate the effect of soft material properties, urethane rubber with hardness of 20, 40 and 60 shore A is utilized. Also, the punch diameter used in this study is 4mm. Moreover, many drawing experiments are conducted with punch velocities range of (0.1mm/s-100mm/s) to show the effect of process velocity. FEA using the commercial software ABAQUS/Standard is used to simulate the drawing process at micro scale. A hyperelastic material model is adopted to define the flexible pad and an elastic-plastic model is defined for the blanks.