Edge instabilities in thin plates studied by in situ transmission electron microscopy

The morphological instability of thin foil edges at elevated temperature is studied by in situ TEM. Quasi-periodic instabilities in the edge profile are observed to develop with a distinct growth direction perpendicular to the original foil edge direction. This results in the development of relatively thick rods perpendicular to the original edge. The rods are then observed to undergo spheroidization. The use of in situ techniques allows the direct study of the thickness changes associated with the formation and propagation of this instability. Such examination of the details of the thickness changes is critical to a full understanding and perhaps the control of the phenomenon.