MEASUREMENT OF VOID SHAPE FROM THE FRACTURE SURFACE USING THE 3-DIMENSIONAL SEM DATA

The tensile tests are conducted and the voidshape is measured using the 3-dimensional SEM (scanning electron microscope)on the tensile test ductile fracture surface by changing the notch radius oftensile test specimens, which is made of the SiC reinforced metal matrixcomposite material. The effects of void configuration and coalescence underthe different stress-triaxiality condition are analyzed. The results showthat the average void aspect ratio increases with the averagevoid size. It means that the stress triaxiality and strain constraint play animportant role during the damage process. These experimental results couldbe used to correctly simulate the ductile damage process of the metal matrixmaterial under the multi-dimensional loads, to propose a reasonablestrength evaluation method and to reveal the ductile damagemechanism.