Application of Numerical Methods of Determining the Crystal Structure Parameters Based on a Single Diffraction Line Profile

2005 ◽  
Vol 48 (4) ◽  
pp. 412-416
Author(s):  
V. V. Korchevskii
Metals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 60 ◽  
Author(s):  
Ryan Cottam ◽  
Suresh Palanisamy ◽  
Maxim Avdeev ◽  
Tom Jarvis ◽  
Chad Henry ◽  
...  

Wedge-shaped samples were manufactured by four different Additive Manufacturing (AM) processes, namely selective laser melting (SLM), electron beam melting (EBM), direct metal deposition (DMD), and wire and arc additive manufacturing (WAAM), using Ti-6Al-4V as the feed material. A high-resolution powder diffractometer was used to measure the diffraction patterns of the samples whilst rotated about two axes to collect detected neutrons from all possible lattice planes. The diffraction pattern of a LaB6 standard powder sample was also measured to characterize the instrumental broadening and peak shapes necessary for the Diffraction Line Profile Analysis. The line profile analysis was conducted using the extended Convolution Multiple Whole Profile (eCMWP) procedure. Once analyzed, it was found that there was significant variation in the dislocation densities between the SLMed and the EBMed samples, although having a similar manufacturing technique. While the samples fabricated via WAAM and the DMD processes showed almost similar dislocation densities, they were, however, different in comparison to the other two AM processes, as expected. The hexagonal (HCP) crystal structure of the predominant α-Ti phase allowed a breakdown of the percentage of the Burgers’ vectors possible for this crystal structure. All four techniques exhibited different combinations of the three possible Burgers’ vectors, and these differences were attributed to the variation in the cooling rates experienced by the parts fabricated using these AM processes.


2018 ◽  
Vol 74 (6) ◽  
pp. 640-646
Author(s):  
K. R. Beyerlein ◽  
P. Scardi

An accurate description of the diffraction line profile from nanocrystalline powders can be obtained by a spherical harmonics expansion of the profile function. The procedure outlined in this work is found to be computationally efficient and applicable to the line profile for any crystallite shape and size. Practical examples of the diffraction pattern peak profiles resulting from cubic crystallites between 1 and 100 nm in size are shown.


1994 ◽  
Vol 73 (1) ◽  
pp. 102-105 ◽  
Author(s):  
I. R. Peterson ◽  
V. M. Kaganer

2004 ◽  
Vol 27 (1) ◽  
pp. 59-67 ◽  
Author(s):  
K. Kapoor ◽  
D. Lahiri ◽  
S. V. R. Rao ◽  
T. Sanyal ◽  
B. P. Kashyap

2001 ◽  
Vol 378-381 ◽  
pp. 753-758
Author(s):  
Alexandre Boulle ◽  
C. Legrand ◽  
P. Thomas ◽  
R. Guinebretière ◽  
J.P. Mercurio ◽  
...  

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