DEMONSTRATION OF THE APPLICATION OF SUPERPLASTIC FORMING USING INFRARED HEATING EMITTERS TO A PART OF STRUCTURE INCLUDING VARIOUS GEOMETRICAL SINGULARITIES

ArianeGroup and Aurock led a feasibility study through the realization of a scale1 TA6V demonstrator, using Infrared superplastic forming (SPF). ArianeGroup designed the demonstrator according to its knowledge of representative structures, comprising singularities: welds, stiffeners and areas with important thicknesses variations. Aurock performed first numerical simulations of the complete process in order to highlight and anticipate the industrial difficulties to be solved. Then, the demonstrator was physically carried out.

Once the demonstration was virtually obtained, each steps of the process were experimented: welding of thick plates, machining of flat panels, pre-forming by rolling and final SPF. For the SPF step, an infrared heating cover and a reinforced refractory castable die with a non-planar seal path were manufactured. Infrared emitters’ position and heating power regulation laws were carefully defined, for the panel to be kept at the correct temperature until being totally formed.

The SPF step led to a successful demonstration of the representative structure. Limited Scale1 demonstration was necessary to ensure the process validity with real thicknesses and thickness variations, which are known to mask problems if scale reductions are used without precautions. The experimental approach confirmed the process modelling predictability. This methodology can be transfer to a real structure only by tooling adaptations, without additional feasibility works. Final water jet cutting was performed and samples were taken for material analysis at the different steps of the process in order to check the material integrity and mechanical properties (nondestructive testing on the panels / tensile behavior / microstructure observations with oxidation layer assessment). Dimensional and thickness controls were also achieved.