The Determination of the Type of Stacking Faults in Face Centered Cubic Alloys by Means of Contrast Effects in the Electron Microscope

A practical method is described for the determination of the nature of stacking faults in facecentred cubic structures. The method involves a comparison of the bright and dark field image of the fringe pattern associated with a stacking fault lying in an inclined plane. A complete analytical derivation of the principles of the method is given, and it is used to show that the stacking faults in a copper ‐15% gallium alloy are of the intrinsic type.