Summary and ConclusionsA series of subscale experimental powder metallurgy disk alloys were evaluated for theirprocessing characteristics and high temperature mechanical properties. Heat treatmentprocedures were developed which could reproduce in subscale disks the cooling paths andmechanical properties of large scale disks. Several subscale alloys had superior tensile andcreep properties at 704 °C and higher temperatures, but were difficult to process and prone toquench cracking, chiefly due to their high gamma prime solvus temperature. Several otheralloys had more favorable processing characteristics due to their lower gamma prime solvustemperature. These alloys often had lower tensile and creep properties at high temperatures.Several experimental low solvus, high property alloys were identified which could build uponthe best attributes of all these alloys, giving exceptional tensile and creep properties at hightemperatures along with good processing characteristics due to a low gamma prime solvus.It can be concluded from this evaluation that:(1) Subscale evaluations of disk alloys can be designed to realistically reproduce thecooling paths and mechanical properties expected from large scale disks.(2) New disk alloy chemistries can be used to improve mechanical properties at hightemperatures.(3) Alloys having high solvus temperature are more prone to form cracks during quenching.(4) An alloy can be designed to provide a low solvus temperature for ease in processingwith exceptional tensile and creep properties at high temperatures.References