Determination of matrix and precipitate elastic constants in (gamma-gamma ') Ni-base model alloys, and their relevance to rafting

A complete set of high-temperature data relevant to rafting, i.e. the elast ic constants of the individual gamma and gamma' phases and the elevated tem perature lattice mismatch between the phases, was generated for two model t ernary Ni-Al-Mo single crystal alloys. The directionality of rafting was ex amined experimentally in the same alloys upon uniaxial loading in compressi on and tension along a (100) cube axis. The key material properties and cor responding directional coarsening observations are discussed in view of the various models for rafting published in the literature. (C) 1999 Elsevier Science S.A. All rights reserved.