Local deformation behavior of Al-matrix-composites by in situ testing and advanced mathematical image correlationWednesday (26.09.2018) 15:00 - 15:15 S1/01 - A02 Part of:
Due to ecological and economical requirements in aerospace and automotive applications, lightweight materials, e.g. aluminum alloys, are used to a wide extent . To extend the specific properties of future components, reinforcing elements like fibers, whiskers or particles can be added to the metal matrix, resulting in e.g. increased Young´s modulus, or creep resistance. Metal matrix composite (MMC) structures are in most cases designed assuming homogeneous mechanical properties, i.e. not taking explicitly into account the distinct differences in local mechanical properties of brittle particles and ductile matrix . Hence, there is still potential for improved design approaches for lightweight design using such multiphase materials.
In the present work, aluminum matrix composites (AMC) consisting of an AA2124 aerospace wrought aluminum alloy matrix reinforced by silicon carbide particles (SiC) with a nominal volume content of 17 % are investigated. The AMC is manufactured by powder metallurgy and supplied as extruded bars in the heat-treatment condition T6 (solution-annealed and artificially aged).
The local deformation behavior is investigated by an in situ mechanical loading system mounted in a scanning electron microscope (SEM). Monotonic and cyclic experiments were realized on notched AMC samples. This allows an in situ digital image acquisition in defined deformation states to monitor the microstructural changes at the surface by high resolution micrographs. These image sequences are the basis for a highly sensitive computation of local displacements and strains as well as resulting crack paths by a variational method from mathematical image analysis .
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