Stress‐Strain Analysis of Single Cubic Crystals and Its Application to the Ordering of CuAu I. Paper II

A stress‐strain analysis of single cubic crystals is developed which utilizes the strain data supplied by the x‐ray back‐reflection divergent beam method. The principal strains and their directions are determined and from the principal strains and the known elastic constants the complete stress‐strain configuration is obtained. Thus the maximum magnitude and the direction of the shearing strain on a given set of crystallographic planes are obtained and the set of planes on which the maximum value of the shearing maxima occurs is also determined. From a knowledge of the stress‐strain configuration, the stored elastic energy of the crystal is deduced; it can be partitioned into two components, that due to shearing strains and that due to a mixture of normal and shearing strains.The conditions under which the principal stress system coincides with the principal strain system are also investigated. Furthermore, a number is constructed that measures the distortion of the crystal in terms of the energy incremen...