Characterization of the microstructure of severely deformed titanium by X-ray diffraction profile analysis

Nanocrystalline titanium was produced by equal channel angular pressing (ECAP). It was found that during ECAP a texture evolved in the specimen in which the hexagonal "c" axis is perpendicular to the extrusion direction. The crystallite size distribution and the dislocation structure were determined by fitting ab-initio theoretical functions to the Fourier coefficients of the measured X-ray diffraction peak profiles. The peak profile analysis provided the median and the variance of the crystallite size distribution: m=38 nm and sigma=0.49, respectively. The dislocation slip system population was found to be 75% <a> type, 20% <c> type and 5% <c+a> type.