The effects of isothermal deformation and annealing on the microstructure of nickel-aluminum-bronze propeller material

This thesis is a study of annealing and isothermal deformation characteristics of cast Nickel-Aluminum Bronze (NAB) in relation to Friction Stir Processing (FSP) of this material. Cast NAB is widely utilized by the U.S. Navy in the production of propellers for surface vessel and submarines. FSP is a novel method of deformation processing that is conducted by use of a rotating tool that is forced onto the surface of a material under load such that sliding and sticking friction result in a combination of frictional heating and adiabatic heating due to plastic deformation. A stirring effect results in the formation of a zone of severe shear deformation and local temperatures approaching 90% of the melting temperature. FSP results in local homogenization of the cast microstructure and conversion of it to a wrought condition in the absence of macroscopic shape change, but also in steep strain, strain rate and temperature gradients. In this thesis microstructures achieved through controlled isothermal deformation and annealing processes are recorded and analyzed. Studies of warm rolling, channel die compression and various annealing schedules were completed.

Department dc:contributor.department

Mechanical Engineering

Grantor dc:publisher

Monterey, California. Naval Postgraduate School

Year dc:date.issued

2003

Author dc:creator

• Nabach, William A.

Advisor dc:contributor.advisor

• McNelley, Terry R.

Statement dc: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.

Handle dc:identifier.uri

https://hdl.handle.net/10945/6106

OAI identifier oai:identifier

oai:calhoun.nps.edu:10945/6106