skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Analysis of neutron diffraction spectra acquired [ital in situ] during stress-induced transformations in superelastic NiTi

Abstract

Neutron diffraction spectra were obtained during various stages of a reversible stress-induced austenite to martensite phase transformation in superelastic NiTi. This was accomplished by neutron diffraction measurements on bulk polycrystalline NiTi samples simultaneously subjected to mechanical loading. Analysis of the data was carried out using individual lattice plane ([ital hkl]) reflections as well as by Rietveld refinement. In the Rietveld procedure, strains in austenite were described in terms of an isotropic ([ital hkl] independent) and an anisotropic ([ital hkl] dependent) component. At higher stresses, austenite lattice plane reflections exhibited nonlinear and dissimilar elastic responses which may be attributed to the transformation. The texture evolution is significant in both austenite and martensite phases during the transformation and two approaches were used to describe this evolving texture, i.e., an ellipsoidal model due to March[endash]Dollase and a generalized spherical-harmonic approach. The respective predictions of the phase fraction evolution as a function of applied stress were compared. A methodology is thus established to quantify the discrete phase strains, phase volume fractions, and texture during such transformations. [copyright] [ital 1999 American Institute of Physics.]

Authors:
 [1];  [2];  [1]
  1. (Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States))
  2. (LANSCE/MST, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States))
Publication Date:
OSTI Identifier:
6337570
Alternate Identifier(s):
OSTI ID: 6337570
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 86:6; Journal ID: ISSN 0021-8979
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; AUSTENITE; ELASTICITY; MARTENSITE; NEUTRON DIFFRACTION; NICKEL ALLOYS; PHASE TRANSFORMATIONS; POLYCRYSTALS; SHAPE MEMORY EFFECT; STRESSES; TEXTURE; TITANIUM ALLOYS; ALLOYS; CARBON ADDITIONS; COHERENT SCATTERING; CRYSTALS; DIFFRACTION; IRON ALLOYS; MECHANICAL PROPERTIES; SCATTERING; TENSILE PROPERTIES 360102* -- Metals & Alloys-- Structure & Phase Studies; 665100 -- Nuclear Techniques in Condensed Matter Physics -- (1992-)

Citation Formats

Vaidyanathan, R., Bourke, M.A., and Dunand, D.C. Analysis of neutron diffraction spectra acquired [ital in situ] during stress-induced transformations in superelastic NiTi. United States: N. p., 1999. Web. doi:10.1063/1.371163.
Vaidyanathan, R., Bourke, M.A., & Dunand, D.C. Analysis of neutron diffraction spectra acquired [ital in situ] during stress-induced transformations in superelastic NiTi. United States. doi:10.1063/1.371163.
Vaidyanathan, R., Bourke, M.A., and Dunand, D.C. Wed . "Analysis of neutron diffraction spectra acquired [ital in situ] during stress-induced transformations in superelastic NiTi". United States. doi:10.1063/1.371163.
@article{osti_6337570,
title = {Analysis of neutron diffraction spectra acquired [ital in situ] during stress-induced transformations in superelastic NiTi},
author = {Vaidyanathan, R. and Bourke, M.A. and Dunand, D.C.},
abstractNote = {Neutron diffraction spectra were obtained during various stages of a reversible stress-induced austenite to martensite phase transformation in superelastic NiTi. This was accomplished by neutron diffraction measurements on bulk polycrystalline NiTi samples simultaneously subjected to mechanical loading. Analysis of the data was carried out using individual lattice plane ([ital hkl]) reflections as well as by Rietveld refinement. In the Rietveld procedure, strains in austenite were described in terms of an isotropic ([ital hkl] independent) and an anisotropic ([ital hkl] dependent) component. At higher stresses, austenite lattice plane reflections exhibited nonlinear and dissimilar elastic responses which may be attributed to the transformation. The texture evolution is significant in both austenite and martensite phases during the transformation and two approaches were used to describe this evolving texture, i.e., an ellipsoidal model due to March[endash]Dollase and a generalized spherical-harmonic approach. The respective predictions of the phase fraction evolution as a function of applied stress were compared. A methodology is thus established to quantify the discrete phase strains, phase volume fractions, and texture during such transformations. [copyright] [ital 1999 American Institute of Physics.]},
doi = {10.1063/1.371163},
journal = {Journal of Applied Physics},
issn = {0021-8979},
number = ,
volume = 86:6,
place = {United States},
year = {1999},
month = {9}
}