Generally, forming processes can be divided into hot forming, cold forming, and hydro forming. However, in the aviation industry, rubber forming in tunnel or hydraulic presses is used. This process is characterized by the use of a rubber punch and pressure using a steel matrix. The use of FEM software during technological instrumentation design, i.e., construction of the die with elastomeric or rubber plates, significantly simplifies the creation of prototype parts and small quantities of a series. Determining the forming parameters and choosing the right rubber or elastomer punch is a technological problem which must be solved at the development stage of the forming process technology. Each analysed process for another elastomer material requires additional research in order to prepare the data correctly for the FEM material model.
In this paper, the authors present and describe the method of stamping austenitic sheets by using several types of elastomers of varying hardness tested in laboratory conditions on a hydraulic press.
There are several ways of forming by means of a flexible punch, such as stamping in two jumps of the slider, i.e., first the elastomer plate itself (incomplete pre-stamping) and in the next phase by adding an additional flexible plate to the blank – finishing stamping. Dividing the stamping into stages increases the durability of the tool. Usually, rubber or elastomer spacers with a 40-50 Shore hardness are used for the finishing stamping process. For hydraulic stamping, the pressure demand can be calculated using the formula: P=qF [kG], where F – free surface projection of the workpiece [mm2], q – liquid pressure at the final drawing moment [kG/mm2].
