The influence of temperature on lattice parameters of coexisting phases in NiTi shape memory alloys - A neutron diffraction study

Khalil-Allafi, Jafar; Schmahl, Wolfgang W.; Wagner, M.; Sitepu, H.; Többens, D. M. and Eggeler, Gunther (2004): The influence of temperature on lattice parameters of coexisting phases in NiTi shape memory alloys - A neutron diffraction study. In: Materials Science and Engineering A, Vol. 378, No. 1-2 SPEC. ISS: pp. 161-164

Abstract

NiTi shape memory alloys were investigated by Rietveld refinement of neutron diffraction data at various temperatures. For an aged sample of nominal composition Ni50.7Ti49.3 at 294 K, B2 austenite, R-phase, and Ni4Ti3 precipitates coexist, and the Rietveld refinement provides accurate lattice parameters for the phases in this microstructure. The observed rhombohedral shape deformation occurring with the formation of Ni4Ti3 and R-phase in the B2 matrix is similar in magnitude and of opposite sign. Thus the strain field around a Ni4Ti3 precipitate can be compensated by a single variant of R-phase.

• Item Type: Journal article
• Faculties: Geosciences > Department of Earth and Environmental Sciences > Crystallography and Materials Science
• Subjects: 500 Science > 550 Earth sciences and geology
• Language: English