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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Effects of laboratory rolling conditions on continuously cast AA5083

Thompson, Matthew F. 06 1900 (has links)
Quick Plastic Forming (QPF) is a recent adaptation of Superplastic Forming (SPF) that allows economical fabrication of complex components using superplastic material. QPF requires refined, equiaxed grains and high-angle grain boundaries in the microstructure to enhance sheet deformation by GBS at the high strain rates involved. This study evaluates the effects of laboratory rolling conditions on continuously cast AA5083 in the hot-band condition in anticipation of QPF. Orientation imaging microscopy, scanning electron microscopy and X-ray analysis were used to analyze roles of the geometric dynamic recrystallization and particle stimulated nucleation of recrystallization in the microstructure evolution during rolling. A refined microstructure was developed during the rolling procedures but mechanical property data indicated low to moderate ductility and failure by excessive cavity formation. Factors influencing the development of microstructure and mechanical properties during laboratory rolling were investigated. / US Navy (USN) author.
2

Analysis of the transition in deformation mechanisms in superplastic 5083 aluminum alloys by orientation imaging microscopy

Harrell, James William 09 1900 (has links)
m alloys used in automotive, aerospace and military applications. Superplasticity requires fine grains with high-angle boundaries and resistance to failure by cavitation. OIM permits grain-specific orientation determination and quantitative assessment of the grain-to-grain disorientation distribution as well as grain size measurement in materials. The current work offers significant new insights into the development and response of superplastic microstructures; in particular, OIM data may be employed to delineate the transition from slip to grain boundary sliding in superplastic 5083 materials. / US Navy (USN) author
3

The Development and Analysis of Low Temperature Superplasticity in AZ91 Magnesium Alloy

Lin, Hsuan-Kai 16 July 2001 (has links)
none
4

Analysis of the transition in deformation mechanisms in superplastic 5083 aluminum alloys by orientation imaging microscopy /

Harrell, James William. January 2002 (has links) (PDF)
Thesis (M.S.)--Naval Postgraduate School, 2002. / Thesis advisor(s): Terry R. McNelley. Includes bibliographical references (p. 81-82). Also available online.
5

Development, production and testing of superplastically formed zinc-aluminum sandwich cores

Crooks, Roy Edmond 08 1900 (has links)
No description available.
6

Friction stir processing of AS-CAST AA5083 Superplastic response /

Hayashi, John Toshio. January 2009 (has links) (PDF)
Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, June 2009. / Thesis Advisor(s): McNelley, Terry R. ; Su, Jianqing. "June 2009." Description based on title screen as viewed on July 10, 2009. Author(s) subject terms: Friction Stir Processing, Superplasticity, Elevated Temperature, Aluminum, Grain Refinement, Strain Rate. Includes bibliographical references (p.49-50). Also available in print.
7

An OIM study of some superplastic aluminum alloys

Conn, John Edward. Kalu, Peter N. January 2004 (has links)
Thesis (M.S.)--Florida State University, 2004. / Advisor: Dr. Peter N. Kalu, Florida State University, College of Engineering, Dept. of Mechanical Engineering. Title and description from dissertation home page (viewed Sept. 24, 2004). Includes bibliographical references.
8

Grain size control by thermomechanical processing (TMP) : the role of dispersed particles /

Orellano, Ramiro E. January 2003 (has links) (PDF)
Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, September 2003. / Thesis Advisor(s): Terry R. McNelley. Includes bibliographical references (p. 89-91). Also available online.
9

Study of processing and microstructure of a superplastic 5083 aluminum alloy /

Maestas, Tracy A. January 2002 (has links) (PDF)
Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, March 2002. / Thesis advisor(s): Terry R. McNelley. Includes bibliographical references (p. 57-58). Also available online.
10

Grain size control in AA5083: thermomechanical processing and particle stimulated nucelation

Deffenbaugh, Kristen Lynn 06 1900 (has links)
Approved for public release; distribution is unlimited / "Superplastic forming is an emerging industrial technology that allows the production of complex shapes in metallic materials including aluminum. A critical characteristic of materials that are capable of sustaining superplastic forming is a fine grain size. In this study a commercial aluminum-magnesium-manganese alloy received in the as-cast condition was subjected to various thermomechanical processes intended to refine the grain size. Particle stimulated nucleation (PSN) theory was employed to develop the thermomechanical processes. These processes all involved initial homogenization and hot working. Subsequent annealing treatments were intended to control the size and size distribution of second phase particles, such as Al6Mn. Strain energy was introduced through cold rolling followed by recrystallization anneals. Samples were analyzed using orientation-imaging microscopy to examine the effect of processing variables on the recrystallized grain size." p. i. / Ensign, United States Navy

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