Accession Number:
ADA000373
Title:
Influence of Stress on Precipitation and Coarsening in Alloys.
Descriptive Note:
Final rept.,
Corporate Author:
UNIVERSITY OF SOUTHERN CALIFORNIA LOS ANGELES ELECTRONIC SCIENCES LAB
Personal Author(s):
Report Date:
1974-09-01
Pagination or Media Count:
20.0
Abstract:
Scanning and transmission electron microscopy of precipitate morphologies of normalized and stress-aged Udimet 700 and Ni9 Al wt pct alloys were studied. In both alloys, rods and plates are formed by a coarsening process involving shape change and agglomeration. All experimental observations, the stress aging behavior of Mar-M200, the NiAl-Cr eutectic and the various omega containing titanium-base alloys can be understood on the basis that the morphology forms, and minimizes a free energy including interfacial energy, residual strain energy and interaction energy terms. A method of estimating the residual strain energy and interaction energy of an infinite plate, infinite rod and cuboidal composite has been developed. A theory of diffusional creep has been developed for binary metallic solid-solutions subjected to a uniform uniaxial state of stress. Several predictions of the theory have been confirmed in NiCr and NiW solid solutions.
Descriptors:
Subject Categories:
- Metallurgy and Metallography