Fractography of Bi-permeated copper bicrystal

Abstract

Intensive investigations about the intergranular embrittlement of copper caused by a small amount of bismuth have been carried out in many laboratories since the first paper appeared in 1947 (]). Although well-developed crystallographic facets formed at grain boundaries following annealing have been observed for years (2,3), information about the crystallographic orientations of the facets is still deficient. While the fracture surface features are generally characterized by means of scanning electron microscopy (SEM), the crystallographic orientations involved in the faceting, however, can not be obtained by means of SEM. Reflection electron microscopy (REM) developed in recent years is a potential technique for the surface observation of bulk crystals with a higher resolution than SEM (4-7). Another advantage of RF~ over SEM is to obtain orientational information about the traces on the REM micrographs. The purpose of this paper is to present the surface structure of embrittled copper bicrystal with a modified REM method by using a conventional transmission electron microscope.