Effects of elastic anisotropy on CTEM dislocation images in L10 alloys: An assessment of the sensitivity computed images to input parameters

Abstract

Ordered alloys have important applications as high temperature structural materials. Grain boundary embrittlement, however, is a major obstacle in their practical applications. The details of grain boundary structure have been suggested to be important in determining the mechanical properties, and it is therefore important to have a better understanding of grain boundary structure in these alloys.Conventional g.b and g.b×U techniques for the determination of Burgers vectors of lattice and grain boundary dislocations are limited by the magnitude of the Burgers vectors and spacing of the dislocations. The dislocations may not be detected if the magnitude of the Burgers vectors is less than 0.05nm or the spacings less than one third of the extinction distance. The strengths of grain boundary dislocations are usually very small, therefore in determining the Burgers vectors of grain boundary dislocations, computer image matching techniques are generally used in conjunction with the usual g.b and g.b×U techniques.