Surface segregation as a guide to grain boundary segregation

Abstract

1. (i) Where grain boundary fracture is not possible for Aes examination, grain boundary segregants can be identified directly from surface segregation observations. 2. (ii) For quantitative evaluation of grain boundary segregation levels, a conversion diagram, incorporating both surface and grain boundary segregation curves as a function of solute content, is required. In the diagram, the important, low solute content, part of the grain boundary curve is experimentally inaccessible and has to be extrapolated from measurements on brittle alloys with artificially increased solute content. 3. (iii) Grain boundary segregation behaviour in inhomogeneous alloys with unknown dilute levels of local bulk impurities can then be derived from observations of surface segregation levels and by reference to the relevant conversion diagrams, an example of which is presented in figure 1.