Novel wrought gamma/gamma ' cobalt base superalloys with high strength and improved oxidation resistance

摘要

New polycrystalline Co-base superalloys with gamma/gamma' microstructure have been developed, which show excellent mechanical properties and enhanced oxidation behavior. The gamma' solvus temperature of these alloys is comparatively low giving a large processing window. The yield strength of these alloys is similar to that of wrought Ni-base superalloys. However, the creep strength at 750 degrees C is largely exceeding that of the Ni-base superalloys Waspaloy and Udimet 720Li. Oxidation tests indicate that the oxidation resistance is comparable to commercial Ni-base superalloys. (C) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.