In-situ scanning electron microscope observations of the deformation behaviour of short cracks

Crack opening displacements (COD) of microstructurally short cracks were observed in situ in the scanning electron microscope after cyclic deformation at constant plastic strain amplitude. The COD-load dependence (‘COD loops’) during one load cycle shows significant variations depending on the crack propagation type and on the deformation behaviour of microstructurally short cracks.