MICROFORM focuses on introducing innovative solutions (FE simulation tools, process optimization based on DoE…) in state-of-the-art stretch and hot forming machines to solve the following challenges and demonstrate the feasibility of manufacturing real HLFC skins with variables microperforation patterns.
− Oxygen uptake and oxidation of surface and inside the holes
− Modification of hole size, shape and pitch after forming
− Buckling distortion due to residual stress accumulation and low sheet thickness
− Waviness or overfolds with heavy 3D contours
− Microcracks in hole walls
− Strain concentration in areas of high tensile stresses
− Poor dimensional tolerances due to springback effect
− Limitations on the size and capability of forming and microdrilling machines
The progress beyond the state of the art include:
-Until now only stretch forming of constant microperforation Ti Gr 2 has been proven and hot forming of Ti Gr 5 under shielding conditions. MICROFORM demonstrated suitability of forming Ti Gr 2 and Ti Gr 5 with different microperforation densities and variable patterns in small and large-scale demonstrators.
-There is commercial software to assist on the stretch forming process optimization which is a black box. Performance of existing commercial software (FormCAM) and newly developed FEM models were compared in demonstrators.
-Different strategies to reduce tooling manufacturing costs were investigated.
The main impact of the project is to contribute to reach the environmental objectives set up for aviation. MICROFORM will improve the wing efficiency to reduce fuel burn, CO2, NOx and noise. Thus, it will be ensured the development of cost-effective manufacturing processes for pre-serial production of HLFC wings. It is expected to reduce setup and forming process development costs of new parts by 30% and forming process development times by 30%. So, the project will also contribute to improve the European aeronautic industry competitiveness by pushing the EU to the forefront in the area of HLFC.
