Hypoeutectic and eutectic Al-Si alloys (from 7wt% to ~12wt% of Si) are widely used in various engine components due to their high-strength-to-weight ratio, heat conductivity, corrosion resistance and their castability. These alloys are essentially composite materials and their thermo-mechanical properties depend strongly on Si content and production route resulting in various microstructures. The design specifications of modern combustion engines demand high accuracy in describing material properties (macro- and microscopic) in complex service simulations.
The current work describes an experimental approach that combines non-destructive diffraction and imaging techniques to investigate the elastoplastic deformation behaviour of Al-Si alloys.
Neutron diffraction is applied for phase specific microstrain measurements under external load at ambient and high temperatures. Complementary synchrotron tomography is performed for imaging of microcrack formation and damage within the microstructure. Stress-induced micromechanical deformation mechanisms could be revealed and correlated to damage mechanisms critical for engine components under operating conditions.