SMALL-ANGLE NEUTRON SCATTERING OF PRECIPITATES IN Ni-RICH Ni-Ti ALLOYS-I. METASTABLE STATES IN POLY-AND SINGLE CRYSTALS

摘要

Two successive metastable regimes of decomposition are revealed in Ni-(10.8-11.9) at./100 Ti single crystals and polycrystals by small-angle neutron scattering (SANS) after various aging steps at 835 K. During the first two hours of aging, the Ti concentration in I-rich regions grows linearly with time, while their size remains unchanged. After a few hours, an intermediate plateau in the integrated SANS intensity is reached and indicates an intermediate metastable state.