Lawrence Livermore National Laboratory (LLNL) and Sandia National Laboratory (SNL) are collaborating on the development of new techniques to study damage evolution and growth in material specimens subjected to mechanical testing. These techniques include metallography, radiography, computed tomography (CT) and modeling. The material specimens being studied include cast magnesium and aluminum alloys, and forged stainless steel. We will concentrate on characterizing mechanically deformed magnesium alloy specimens using computed tomography. Several notched tensile magnesium specimens were uniaxially loaded to obtain different levels of deformation. Specimens were initially characterized by radiography and computed tomography to determine the preloaded state. Subsequent CT scans were performed at different displacement percentages. The CT volumetric data are being used to measure void volume fraction in all three dimensions nondestructively to determine the effect of void growth on the mechanical behavior of the materials.
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