EARLY STAGES OF PRECIPITATE RAFTING IN A SINGLE CRYSTAL Ni-Al-Mo MODEL ALLOY INVESTIGATED BY SMALL-ANGLE X-RAY SCATTERING AND TEM

摘要

A combination of small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) has been used to investigate experimentally the earl stages of directional coarsening (rafting) of the γ' precipitates in a single crystal Ni-Al-Mo model alloy under uniaxial tension along [001]. The precipitates were found to form plate-like rafts perpendicular to the direction of the applied load. Based on microscopic observations ,quantitative models for evaluation of the SAXS data were developed, permitting extraction of important structural information from the two-dimensional SAXS spectra on the sapect ratio of the rafts and the waviness of their interfaces.