Premium
Small‐angle neutron scattering investigation of the early stages of decomposition in Ni‐rich Ni‐Ti
Author(s) -
Kompatscher M.,
Schönfeld B.,
Heinrich H.,
Kostorz G.
Publication year - 2000
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s0021889800099957
Subject(s) - metastability , spinodal decomposition , crystallite , neutron scattering , scattering , small angle neutron scattering , materials science , crystallography , neutron diffraction , plateau (mathematics) , phase (matter) , neutron , condensed matter physics , crystal (programming language) , single crystal , small angle scattering , crystal structure , chemistry , optics , physics , nuclear physics , mathematical analysis , programming language , mathematics , organic chemistry , computer science
In‐situ small‐angle neutron scattering was performed on polycrystals and single crystals of Ni‐10 to 12 at.% Ti at temperatures between 900 and 1240 K. A plateau in the integrated intensity as a function of aging time for polycrystalline Ni‐11.3 at.% Ti at 900 K indicates the presence of a precursor state γ'' preceding the formation of the metastable γ' state, with a Ti concentration of 16.5(1.0) at.% in the particles. In the scattering patterns of a Ni‐12.0 at.% Ti single crystal aged at 1200 and 1240 K, strong scattering intensities along <100> related to the coherent γ''/γ' states, and sharp streaks along <111> related to plates of the stable η phase appear successively. At 1240 K, the presence of the L12‐related intensities along <100> is unexpected, as this temperature lies above the metastable miscibility gap suggested in the literature.