Determination of the stress orientation distribution function using pulsed neutron sources

Abstract

The stress orientation distribution function (SODF) was recently introduced as a mean-®eld representation to describe the grain-orientation dependence of intergranular stress. Pulsed neutron sources are ideally suited for the determination of the SODF since multiple re¯ections can be measured simultaneously with comparable precision. A method is developed for constructing the SODF from strain pole ®gures measured with a pulsed neutron source and demonstrated with cold-rolled interstitial-free steel. The experimental results are compared with those measured with a reactor-based constantwavelength diffractometer. It is shown that access to a large number of re¯ections on a pulsed neutron source improves the precision of the experimental SODF and facilitates in situ studies of the evolution of the intergranular stress during deformation and annealing.

Total pattern fitting for the combined size–strain–stress–texture determination in thin film diffraction

“…The method is very similar to the one of Wang et al [26] but it is more convenient for integration into a multipattern Rietveld scheme as less computation is needed. Either the macrostrain or the full strain orientation distribution function can be obtained by the method and no assumptions are needed for the elastic properties or the nature of the strain.…”

Temperature-dependent elastic anisotropy and mesoscale deformation in a nanostructured ferritic alloy

“…The second approach has been developed as a tool for residual stress determination in deformed specimens after the external load is released. The macroscopic stress components are not known in this case; it is thus necessary to define a mesoscopic average stress field depending on the grain orientations, known as the stress orientation distribution function [25][26][27][28] . In this case, the proportionality factors between the strain and stress components are fully determined by the single-crystal elastic constants, although additional restrictive conditions or grain interaction models are often needed to obtain physically consistent solutions for the stress field.…”

Inter- and intragranular stresses in cyclically-deformed 316 stainless steel

“…Because GPPD has a rather large detector coverage (54-156 • 2θ), it is ideally suited for the determination of crystallographic texture and intergranular strains. Measurements of the orientation-dependent lattice strains followed the procedures outlined previously [10,14]. Although diffraction data were collected simultaneously in all detector banks, only those from the high-angle detector banks, with nominal scattering angles 2θ = ±126 • , ±144 • , were used in the present analysis in order achieve highprecision for the determination of lattice strains and peak widths.…”