Mechanical properties of iron-cobalt alloys for power applications

The United States Air Force is in the process of developing magnetic bearings as well as an aircraft integrated power unit and an internal starter/generator for main propulsion engines. These developments are the driving force for the new emphasis on high temperature, high strength magnetic materials for power applications. Analytical work, utilizing elasticity theory, in conjunction with design requirements, indicates a need for magnetic materials to have strengths in excess of 80 ksi up to about 1000°F. Two specific iron-cobalt alloys have been tested as part of a magnetic materials characterization program at Wright Laboratory. The first material is Hiperco(R) Alloy 50HS from Carpenter Technology Corporation and the second is HS50 from Telcon Limited. The effect of composition and heat treatment of these two soft magnetic materials on mechanical behavior and the impact on potential aircraft power applications is discussed