Effect of Heat Treatment on Magnetic and Mechanical Properties of an Iron-Cobalt-Vanadium-Niobium Alloy

Iron-cobalt-vanadium alloys can be processed to have excellent soft magnetic properties for use in high performance power generation applications such as the rotors and stators of aircraft integrated power units. These soft magnetic properties are, however, developed at the expense of mechanical strength and toughness. Small additions of niobium are reported to increase the strength of these Fe-Co-V alloys. This study evaluates the effects of heat treatment on the mechanical and magnetic properties of heavily cold work strip of a 48 wt.% iron-48 wt.% cobalt-2 wt.% vanadium alloy with a 0.3 wt.% addition of niobium. For heat treatments between 640 and 740°C for 1 hour the tensile and yield strengths and ductility of the alloy were all found to be superior to a similar alloy found in the literature without the addition of Nb and processed in a similar manner. Magnetic permeability, remnant induction, saturation induction, coercivity and core loss were only slightly degraded at all annealing temperatures when compared with the non-niobium containing alloy. All properties were shown to depend primarily on degree of recrystallization of the sample, which was found to fully recrystallize between 720 and 740 °C for 1 hour anneals. No significant change in measured properties were found when annealing time was increased to 2 hours. Full recrystallization was observed for samples annealed for as short of times as 10 minutes at 800 °C.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Materials Science and Engineering

Department dc:contributor.department

Materials Science and Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2001

Author dc:creator

• Hailer, Benjamin Thomas

Chairs dc:contributor.committeechair

• Reynolds, William T. Jr.
• Kampe, Stephen L.

Committee members dc:contributor.committeemember

• Fingers, Richard T.
• Aning, Alexander O.

• Hiperco 50HS
• magnetic
• Iron Cobalt alloy
• mechanical

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-05032002-144727

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/32135