Non-equibiaxial deformation of W/Cu nanocomposite thin films on stretchable substrate: Effect of loading path

• Non-equibiaxial tensile tests are performed on metallic film-substrate composite.
• Two different loading paths have been performed.
• Applied strains are measured in situ by X-ray diffraction and image correlation.
• Lattice strain and elastic stress–true strain curves are plotted.
• The different mechanical behaviours in the two directions of applied load are revealed.

In situ biaxial tensile tests were carried out on W/Cu nanocomposite thin films deposited on a polyimide cruciform substrate. A biaxial testing machine developed on the DiffAbs beamline at the French SOLEIL synchrotron allows for scrutinizing the mechanical behaviour of crystalline thin films at the micro-scale and the macro-scale using simultaneously synchrotron X-ray diffraction and digital image correlation techniques. Both strain analyses have been performed for two controlled non-equibiaxial loading paths: loading ratios of 0.8 and 0.33. The mechanical response is analysed and compared for the two loading ratios.