Short-range order in Ni-rich Ni-Ti studied by diffuse neutron scattering

Diffuse wide-angle neutron scattering has been measured for Ni-58-5.8 at% T i room temperature after quenching from 777 K, and for Ni-58-9.6 at% Ti at 1103 K. The fitted sets of short-range order and static displacement parame ters are similar to those found in a previous investigation of short-range ordered Ni-8.9 at% Al. Applying a Bragg-Williams model, the coherent solvus of the gamma phase is well reproduced. Neither the displacement parameters nor the phonon dispersion branches measured along [xi xi xi] for the sampl e containing 9.6 at% Ti show any signs of instability of the short-range or dered face centered cubic structure.