The isothermal deformation of nickel aluminum bronze in relation to friction stir processing

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Authors
Pierce, Frank Allen
Subjects
Friction stir processing
Nickel-aluminum bronze
NAB
Isothermal deformation
Annealing
Optical microscopy
Naval propellers
Surface treatment
Thermomechanically affected zone
Shear deformation
Homogenization of microstructure
Grain refinement
Advisors
McNelley, Terry R.
Date of Issue
2004-06
Date
June 2004
Publisher
Monterey, California, Naval Postgraduate School
Language
Abstract
The extreme strain, strain rate and temperature gradients during Friction Stir Processing (FSP) render measurement of key parameters in the stir zone infeasible with common methods. The objective of this research was to separate the effects that temperature and deformation in an experimental study of the microstructure and mechanical properties of Ni-AL bronze (NAB). This was accomplished by subjecting as-cast NAB material to several isothermal annealing and quenching treatments as well as isothermal hot rolling processes. Sufficient material was generated to provide results and data for subsequent optical microscopy, tensile, & hardness tests. All results were then compared to similar data collected from previous works completed here at Naval Postgraduate School and with other DARPA FSP program participants. During the course of this work correlations were drawn between FSP material and the material subjected to isothermal hotworking, which may enhance our understanding of the roles that various FSP process parameters have on the microstructural transformation sequence within this material. The hot-rolling study conducted here suggests that FSP process parameters leading to severe deformation at temperatures between 950-1000 C in the NAB material provides high ductility (elongation approximately 28%) with moderate strengths.
Type
Thesis
Description
Series/Report No
Department
Mechanical and Astronautical Engineering (MAE)
Organization
Naval Postgraduate School (U.S.)
Identifiers
NPS Report Number
Sponsors
Funder
Format
xiv, 55 p. : ill.
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.
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