Residual strain/stress analysis by means of energy-dispersive neutron-transmission diffraction

0185593 - UJF-V 20020104 RIV GB eng C - Konferenční příspěvek (zahraniční konf.)
Mikula, Pavol - Wagner, V. - Vrána, Miroslav - Lukáš, Petr
Residual strain/stress analysis by means of energy-dispersive neutron-transmission diffraction.
Proceedings of the International Conference on Residual Stressed /6./. Oxford: IOM Communications, 2000, s. 1124-1128. ISBN 1-86125-123-8.
[Proceedings of the International Conference on Residual Stresses /6./. Oxford (GB), 10.07.2000-12.07.2000]
Grant CEP: GA ČR GV202/97/K038; GA AV ČR IAA1048003
Klíčová slova: residual strain/stress * neutron-diffraction
Kód oboru RIV: BM - Fyzika pevných látek a magnetismus

A novel modification of the energy-dispersive neutron-transmission diffraction (EDNTD) method for scanning Braff diffraction edges which has been implemented on a conventional diffractometer at a steady state reactor is reported. It is demonstrated that the method requiring precise measurements of the intensity-wavelength dependence, which has been used only on time-of-flight instruments can be also simply and succesfully used at steady state sources. Such an intensity-wavelength dependence can be found in a focused convergent beam coming on a sample from a thin bent perfect monochromator, where, though in a limited .DELTA.é range, the monochromatized beam is strongly é-.lambda. correlated. The presented new technique was in this case tested for a precise scanning of the Bragg diffraction edge and consequently, in scanning of small lattice spacing of polycrystalline materials. This EDNTD technique permits us to determine lattice spacing changes .lambda.d/d with the sensitivity down to 10^-5 for small sample volumes and reasonable counting times even at a medium power research reactor. Thus, it can be used for macro-and/or microstrains scanning in polycrystalline materials.
Trvalý link: http://hdl.handle.net/11104/0081983