Evaluation of ATI 718Plus Thermo-Mechanical Procedures for Turbine-Disk Applications

ATI 718Plus is a Ni-Cr-Co superalloy strengthened by gamma prime precipitation and proposed as a material able to have excellent mechanical properties at temperatures up to 690°C (42°C above conventional 718 superalloy). Several international programs are currently developed in order to determine ATI 718plus characteristics and possible applications. One of these applications is production of disks for aerospace engines by forging procedures. This contribution evaluate ATI 718Plus superalloy when several disks, produced by open die forging, are exposed to thermo-mechanical processing parameters as temperature, soaking time, deformation ratio and heat treating procedures. Mechanical and microstructural properties are reviewed in order to determine conditions to promote best combination of metallurgical characteristics. Mechanical testing and electronic microscopy complement reported results.