Grain size control by thermomechanical processing (TMP) the role of dispersed particles
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Authors
Orellano, Ramiro E.
Subjects
Superplasticity
Grain Size Control
Second Phase Particles
Grain Boundary Sliding
Particle Stimulated Nucleation (PSN)
AA 5083
Grain Size Control
Second Phase Particles
Grain Boundary Sliding
Particle Stimulated Nucleation (PSN)
AA 5083
Advisors
McNelley, Terry R.
Date of Issue
2003-09
Date
Publisher
Monterey, California. Naval Postgraduate School
Language
Abstract
Superplasiticity in Aluminum alloys allows for the economical forming of components of complex shapes while retaining the high-strength and stiffness-to-weight ratios characteristic of alloys used in automotive, aerospace and military applications. Superplastic materials require fine grains with high-angle boundaries having resistance to failure by cavitation. This study was designed to achieve improved control of microstructure of Continuously Cast (CC) AA 5083 utilizing the Particle Stimulated Nucleation (PSN) model as a guide. The studies included a variety of overaging parameters in the thermomechanical process (TMP), followed by a constant processing strain and a subsequent recrystallization annealing treatment. The resulting material was analyzed using optical microscopy, and backscatter electron (BSE) and orientation imaging microscopy (OIM) methods to evaluate the effect of the processing on the grain size and the dispersion of particles.
Type
Thesis
Description
Series/Report No
Department
Mechanical and Astronautical Engineering
Organization
Naval Postgraduate School (U.S.)
Identifiers
NPS Report Number
Sponsors
Funding
Format
xiv, 93 p. : ill. (some col.) ;
Citation
Distribution Statement
Approved for public release; distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.