Method of controlling a superplastic forming machine and corresponding machine

Superplastic forming machine for the forming of a sheet (100) comprising:

• a cover (13),
• a tank (12),
• a press (11) and a peripheral seal (14) both for the gripping of the sheet (100) at its periphery, between the tank (12) and the cover (13), and for the sealing of a forming chamber (15) delimited by the sheet (100),
• members for heating directly by radiation (1-8), arranged facing the sheet (100);
• a gas conduit (16) for the adjusting of the pressure in the forming chamber (15),
• a programmable controller (17) for controlling both the heating power of the members for heating (1-8) and the pressure in the forming chamber (15), characterized in that the programmable controller (17) is programmed according to a forming specification supplied by the method of:
• determining (201) an initial heating configuration comprising the shape to be given, an architecture of the members for heating (1-8), a thickness of the sheet (100) before deformation, an architecture of the cover (13);
• performing a finite-element simulation (202) relating to the temperature of the sheet and performed in such a way as to have a temperature that is substantially consistent across the sheet and substantially constant during forming, in order to obtain (204) a forming specification comprising at least one cycle of powering the members for heating and a cycle of pressure of the forming chamber;
• programming (207) the programmable controller of the superplastic forming machine according to the forming specification supplied by the simulation.