The observation of slip bands in molybdenum single crystals by X-ray diffraction

Abstract

The etch pit technique is a very simple method for the direct observation of dislocations and slip bands in single crystals. However, its use is often limited to certain crystallographic planes. For example, at present there is no report in the literature of an etchant which will reveal intersections on {112} planes of molybdenum. The Berg- Barrett X-ray micrography technique can be used to observe slip bands on a {112} plane. However, before using this method in studies of the growth of slip bands in molybdenum, it was deemed necessary to establish a correspondence between the X-ray contrast and the total slip band length (length of the trace containing dislocations associated with the slip band). To accomplish this goal X-ray topographs of slip bands were compared with the etch pit pattern produced by an electrolytic etchant developed by Das. These observations were made on a {124} surface of molybdenum (since the etchant does not reveal dislocation on a {112} surface).