Files in this item

FilesDescriptionFormat

application/pdf

application/pdf8908673.pdf (6MB)Restricted to U of Illinois
(no description provided)PDF

Description

Title:Radiation-Induced Segregation and Precipitation in Ion-Irradiated Molybdenum-Rhenium Alloys
Author(s):Erck, Robert Alan
Doctoral Committee Chair(s):Rehn, Lynn E.,; Wayman, C. Marvin
Department / Program:Metallurgy and Mining Engineering
Discipline:Metallurgical Engineering
Degree Granting Institution:University of Illinois at Urbana-Champaign
Degree:Ph.D.
Genre:Dissertation
Subject(s):Engineering, Nuclear
Engineering, Metallurgy
Engineering, Materials Science
Abstract:Radiation-induced solute segregation and precipitation in molybdenum-rhenium solid-solution alloys were studied during elevated-temperature helium- and neon-ion irradiation. Radiation-induced segregation of Re atoms in the same direction as the defect fluxes, that is, toward the external surface, was measured during irradiation by in situ Rutherford backscattering spectrometry (RBS). The results of the segregation measurements were in agreement with theoretical models based on point-defect driven transport of solute atoms toward point-defect sinks.
After irradiation, near-surface microstructural changes were studied using transmission-electron microscopy (TEM). Radiation-induced chi-phase precipitates were identified. The precipitates adopted coincident and (111) twin orientations with respect to the matrix. The twinning morphology was explained in terms of a coincident-site-lattice model.
The results of the RBS and TEM studies constitute strong evidence that precipitation of the chi phase occurs in Mo-Re solid-solution alloys when radiation-induced solute segregation causes the equilibrium solubility limit to be exceeded near point-defect sinks.
Issue Date:1988
Type:Text
Description:213 p.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1988.
URI:http://hdl.handle.net/2142/71855
Other Identifier(s):(UMI)AAI8908673
Date Available in IDEALS:2014-12-16
Date Deposited:1988


This item appears in the following Collection(s)

Item Statistics