Study of bimetallic sheets through hydraulic bulge testing

<ns3:p>The purpose of the paper is to investigate the mechanical behaviour of bimetallic sheets manufactured using Laser Powder Bed Fusion (L-PBF) technology and subjected to hydraulic bulge testing. The objective is to analyse the influence of layer configurations and material distribution on the deformation response, aiming to optimise the forming conditions of hybrid additive-manufactured structures.A combined analytical and numerical approach, based on the Finite Element Method (FEM), was employed to predict the deformation and stress distribution during the bulge test. Experimental validations were conducted to verify the accuracy of the simulations. Various configurations of CuCr1Zr and AlSi10Mg layers were produced and tested, with constant total sheet thickness, to assess the impact of material stacking on the mechanical response.The results indicate that the material composition and layer distribution significantly impact the mechanical response of the sheets. Sheets with a higher proportion of CuCr1Zr required greater forming pressures compared to AlSi10Mg. Numerical simulations showed good agreement with experimental results, with relative errors below 10%, validating the accuracy of the developed FEM model. Multilayer bimetallic structures demonstrated enhanced mechanical performance and better control of deformation behaviour.The study is limited to specific materials and simple geometries. Future work will explore more complex shapes, other material combinations, and thermal effects during the forming process. Additionally, the investigation of springback, a critical phenomenon after forming, is recommended to improve the geometrical accuracy of the formed parts.The results provide a basis for optimising additive manufacturing and forming parameters for bimetallic sheets in industrial applications, particularly in the automotive and aerospace sectors. The work contributes to the development of lightweight hybrid structures with tailored mechanical properties.The study is among the first to combine analytical, numerical, and experimental approaches to investigate the hydroforming behaviour of 3D-printed bimetallic sheets. It highlights the importance of material configuration in enhancing the mechanical response and opens the way for better control of forming processes and springback in hybrid additive-manufactured structures.</ns3:p>