New Concepts to Measure, Calculate and Analyze Textures in Materials

In materials and process design, crystallographic texture analysis is used in many ways to control properties of products. In most instances, texture analysis is applied to characterize a material state in terms of its anisotropy in properties. In industrial applications texture analysis is also used to monitor the consistency of a process for example the anisotropy in mechanical properties from product to product. A second application is based on improvements in the accuracy in materials modeling; where simulations of texture evolutions are based on experimental measurements of textures. Given this background, a new concept to measure pole figures, to calculate and analyze ODFs, and to report the results was developed. The new Texture Measurement Instrument (TMI) is based on a transmission X-ray technique with a CCD camera as a detector unit, and a single axis goniometer. The measurement of three pole figures from a sheet of less than 1 mm in thickness takes less than one minute. From these data, ODFs are calculated using a direct inversion method. The main reason to use such an inversion method is the linkage of experimental measurements to simulations such as FEM and VPSC, both requiring in many implementations a set of discrete orientations as input data. For engineering purposes, textures are analyzed in terms of volume fractions of texture components characteristic for a specific process. The concept developed determines the volume fraction as excess of an isotropic distribution, while avoiding overlapping of neighboring peaks. Finally, all data are reported in HTML format to be delivered via the Internet/Intranet protocols (HTTP). [Materials include Mg, Cu, and steel.]