X-ray diffraction line broadening due to dislocations in non-cubic crystalline materials. III. Experimental results for plastically deformed zirconium

Abstract

Procedures of X‐ray diffraction line profile analysis for the evaluation of the dislocation content in plastically deformed hexagonal materials were tested by means of conventional powder diffractometry on polycrystalline zirconium deformed under tension at 77 K. In order to obtain a representative picture of the dislocation‐induced X‐ray line broadening a series of reflections was measured. The integral breadths and the Fourier coefficients were evaluated by both direct profile‐shape analysis and profile fitting with analytical functions. The results show a significant anisotropy of the line broadening. The 0001 reflections are clearly less broadened than most of the others. According to the theoretical calculations presented previously such a phenomenon can be expected if the plastic deformation favours generation of dislocations with Burgers vectors a/3 〈20〉.

Nanocrystalline materials studied by powder diffraction line profile analysis

“…Anisotropic crystallite shape are a delicate phenomenon [26] which has been treated by special elegance in the case of ZnO nanoparticles [23]. Finally, anisotropic strain broadening is a general feature of powder patterns [43][44][45][46][47][48][49][50][51][52][53][54][55][56], which is generally related to dislocations and the elastic properties of crystals. In the present work a few typical examples are reviewed where the microstructure of nanocrystalline materials has been characterized by the method of XLPA.…”

Characterization of defect structures in nanocrystalline materials by X-ray line profile analysis

“…Especially, in the Warren-Averbach procedure it was voluntarily suggested [1] [74], which, however, did not attract much attention until the eighties. Kuzel and Klimanek [75,76] and Ungár et al [77,78] have realized that strain anisotropy can be used to characterize the dislocation structure in more detail. In the modified Williamson-Hall plot [68,77] the FWHM or the integral breadths, DK FWHM or DK b , are scaled versus K 2 C C, where K ¼ 2 sin q/l, q is the diffraction angle and l is the wavelength of X-rays and C C is the avarage dislocation contrast factor, cf.…”

“…[27,28,[33][34][35][36], and (vii) planar defect densities, cf. [1,2,29,[37][38][39][40][41][42][43][44][45][46][47][48][49][50][51] or (viii) different types of internal stresses of first and second order, (ix) especially longrange-internal stresses prevailing in heterogeneous microstructures, cf. [52][53][54][55][56][57][58], (x) fluctuation of chemical composition, cf.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20], (iii) average dislocation density and (iv) dislocation character, cf. [21][22][23][24][25][26][27][28][29][30][31][32] (v) slip activity, (vi) active Burgers vectors, cf. [27,28,[33][34][35][36], and (vii) planar defect densities, cf.…”

Atomistic Model of Metal Nanocrystals with Line Defects: Contribution to Diffraction Line Profile

“…The Krivoglaz-Wilkens approach, using Eq. 1 or similar approximations, is useful and easily implemented in the experimental data analysis; it has been extensively used in materials science (e.g., see work by Klimanek and Kuzel (1988), Kuzel and Klimanek (1988), Kuzel and Klimanek (1989), Ungar et al (1998), Ungar (2008), Scardi and Leoni (2002), Scardi et al (2007)] even if, as a matter of fact, it has never been fully validated. A few studies (Kamminga and Delhez, 2000;Kaganer and Sabelfeld, 2011;Kaganer and Sabelfeld, 2014) have tested Eq.…”