Application of Neutron Diffraction to Measure Residual Strains in Various Engineering Composite Materials

1991 ◽  
Vol 113 (1) ◽  
pp. 51-59 ◽  
Author(s):  
S. Majumdar ◽  
J. P. Singh ◽  
D. Kupperman ◽  
A. D. Krawitz

An experimental neutron diffraction technique was used to measure residual strains that developed in multiphase composite materials during postfabrication cooling as a result of thermal expansion mismatch or volume expansion due to change in crystal structure. The reinforcement geometries that were studied include unidirectional fibers, randomly oriented single crystal whiskers, and equiaxed particles. Both metal and ceramic matrices and reinforcements were considered. In some cases, the measured data compared fairly well with predictions based on simple elastic models. In other cases, either creep was shown to relax the residual strains during cooling, or the interpretation of the measured data contained uncertainties due to texture in the samples or lack of a clearly defined crystal structure for the reinforcement phase.

1975 ◽  
Vol 30 (8) ◽  
pp. 1028-1031
Author(s):  
Harri K. Koski

Abstract The powder pattern of crystalline cubic deuterated acetylene recorded by thermal neutron diffraction technique and the Pa3 crystal structure assigned to the high phase of C2H2 are com-pared. The observations are not in disagreement with the theoretical pattern. Values for the lattice parameters in a narrow temperature range are given.


2020 ◽  
Vol 76 (11) ◽  
pp. 1034-1042
Author(s):  
Santanu Pathak ◽  
Parnika Das ◽  
Tilak Das ◽  
Guruprasad Mandal ◽  
Boby Joseph ◽  
...  

A study on the crystal structure of monoclinic HfO2 has been performed using synchrotron X-ray and neutron diffraction data separately, as well as a combination of both. The precision of the structural parameters increases significantly due to application of the neutron diffraction technique. The experimental oxygen positions in HfO2, derived precisely, are visualized only by semi-local density functional calculations in terms of the calculated electronic band gap, but are not captured as accurately by using hybrid functionals.


Author(s):  
Z. Cheng ◽  
Y. Cheng ◽  
L. Guo ◽  
D. Xu

AbstractThe crystal structure of the title compound D(H)LAP with chemical formula (D


2010 ◽  
Vol 652 ◽  
pp. 111-115 ◽  
Author(s):  
D.G. Hattingh ◽  
Axel Steuwer ◽  
M. Neil James ◽  
I.N. Wedderburn

This paper presents microstructural, hardness and residual strain information for solid-state welds in creep-resistant Cr-Mo steel, made using the new local damage repair technique offered by friction taper stud welding (FTSW). The technique is suitable for making single welds to repair, for example, localised creep damage but can also be extended to deal with planar defects through the use of overlapping welds. Neutron diffraction was used to measure residual strains at a number of positions along a series of 5 overlapping FTS welds.


2005 ◽  
Vol 105 ◽  
pp. 83-88 ◽  
Author(s):  
H. Sitepu ◽  
Heinz Günter Brokmeier

The modelling and/or describing of texture (i.e. preferred crystallographic orientation (PO)) is of critical importance in powder diffraction analysis - for structural study and phase composition. In the present study, the GSAS Rietveld refinement with generalized spherical harmonic (GSH) was used for describing isostatically-pressed molybdite powders neutron powder diffraction data collected in the ILL D1A instrument. The results showed that for texture in a single ND data of molybdite the reasonable crystal structure parameters may be obtained when applying corrections to intensities using the GSH description. Furthermore, the WIMV method was used to extract the texture description directly from a simultaneous refinement with 1368 whole neutron diffraction patterns taken from the sample held in a variety of orientations in the ILL D1B texture goniometer. The results provided a quantitative description of the texture refined simultaneously with the crystal structure. Finally, the (002) molybdite pole-figures were measured using the GKSS TEX2 texture goniometer. The results showed that neutron diffraction is an excellent tool to investigate the texture in molybdite.


2013 ◽  
Vol 58 (4) ◽  
pp. 575-585 ◽  
Author(s):  
N. B. Bolotina ◽  
A. I. Kalyukanov ◽  
T. S. Chernaya ◽  
I. A. Verin ◽  
I. I. Buchinskaya ◽  
...  

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