Thesis (M.S.)--Brigham Young University. Dept. of Mechanical Engineering, 2004. / Includes bibliographical references (p. 83-85).

Thesis (M.S.)--Brigham Young University. Dept. of Mechanical Engineering, 2004. / Includes bibliographical references (p. 27-40).

Thesis (Ph. D.)--Missouri University of Science and Technology, 2008. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed November 4, 2008) Includes bibliographical references.

Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, Sept. 2004. / Thesis advisor(s): Terry R. McNelley. Includes bibliographical references (p. 149-152). Also available online.

Thesis (M.App.Sc.) - Carleton University, 2007. / Includes bibliographical references (p. 115-120). Also available in electronic format on the Internet.

Thesis (M.S.)--Brigham Young University. Dept. of Mechanical Engineering, 2006. / Includes bibliographical references (p. 27-29).

Friction StirWelding (FSW) has been researched for a number of years since its inception in 1991. The work thus far has been based on understanding the material and thermal flow using the standard fixed pin tool. The keyhole resulting during tool extraction in a FSW weld, is a disadvantage and a current limiting factor. Eliminating this effect from a weld using a movable pin tools would make FSW more commercially viable. This dissertation focuses on the design of a novel retractable pin tool, and highlights the problems encountered during the welding of Aluminum plates, Al2024 and Al5083. Previously studied techniques of material and thermal flow were used, to investigate the effect of the tool during extraction in a FSW weld. A prototype retractable tool was designed using parametric and axiomatic design theory, and implementing a pneumatic muscle actuation system. The resulting problems in the calibration of the retractable pin tool and the resulting welds are presented, these results confirming previous studies. The movable pin produced discrepancies the heat generation around the shoulder during a FSW weld. The failure of this tool to produce a reasonable weld showed that previous ideas into the workings of a retractable pin tool requires further investigation, furthermore a fresh approach to the interpretation and understanding of the FSW weld process needs consideration.

Friction Stir Processing (FSP) is currently being considered for use in manufacture of the Navy's NiAl bronze propellers. Incorporating this technology may improve service performance and enable reduction of manufacturing time and cost. This program of research has employed miniature tensile sample designs to examine the distributions of longitudinal properties through the various regimes in a fusion weld. Also, the distributions of both longitudinal and transverse properties throughout the stir zones for selected FSP conditions were examined. Yield strengths were larger in various FSP conditions by at least a factor of two relative to fusion welds. Ultimate strengths were comparable in the weld pool and stir nugget. WidmanstaÌ tten microstructures and microvoid formation and coalescence in the fracture surface resulted in high ductilities in weld metal and the stir nugget. The thermomechanically affected zone of FSP and the heat affected zone of a fusion weld both exhibit low ductility. This may reflect formation of "a" upon heating to temperatures of 800-850 [degrees]C, followed by rapid cooling and transformation of the "a" to form martensitic transformation products in their respective microstructures. For a single-pass raster pattern, transverse ductility is lower than longitudinal ductility. For a multi-pass raster, transverse ductility is higher than longitudinal ductility. For multi-pass raster and spiral patterns in FSP, the data show that the mechanical properties are more nearly isotropic. / US Navy (USN) author.

Thesis (M.S.)--Brigham Young University. Dept. of Mechanical Engineering, 2004. / Includes bibliographical references (p. 163).

Thesis (M.S.)--University of Missouri--Rolla, 2007. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed February 4, 2008) Includes bibliographical references.