Refinamento Rietveld das funções instrumentais e construção de figura de polos inversa

Abstract

The powder X-ray diffraction allows direct investigation of the microstructure, and Rietveld refinement is one of the most widely used method for analyzing such data. The position of the profiles provide the network parameters, the intensity provides information on electron density, preferred directions and quantization stages, among others, the shape of the profile is the result of the instrumental effects, crystallite size and microstrain. In metallic materials with high strain and texture generated by the lamination process, show significant changes in the positions and intensities of the diffraction peaks difficult Rietveld refinement. Thus, it was a written Rietveld refinement software based on kinematic theory of X-ray diffraction to refine the structure of laminate material, and proposed and implemented a method for construction of inverse pole figure from the refined parameters of preferred orientation function. The refinement software was used for the inverse pole figure of ferritic steel subjected to laminations and thermal treatments different. It was also implemented to calculate the convolution function representing the profile instrumental for diffractometer with Bragg-Brentano geometry. It assessed the adjustment of these functions and their influence on the refined value of the network parameters. The values of the parameters refined instrumental functions were used as input parameters in the refinement of the ferritic steel.