The Effects of Isothermal Deformation and Annealing on the Microstructure of Nickel-Aluminum-Bronze Propeller Material
Abstract
This thesis is a study of annealing and 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 as material used 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 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, but also in steep strain, strain rate and temperature gradients. In this thesis microstructures achieved through controlled isothermal deformation and annealing processes will be compared with microstructures resulting from FSP. The use of Friction Stir Processing is envisioned as a way to improve the surface characteristics of the material through localized microstructural modification. Studies of warm rolling, channel die compression and various annealing schedules were completed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2003
- Accession Number
- ADA465673
Entities
People
- William A. Nabach
Organizations
- Naval Postgraduate School