NASA Aeronautics Scholarship Program-Training Grant for Peter Bocchini

The goal of this project is to design new Cobalt-based alloys for use in high-temperature structural applications with specific emphasis on jet-engine turbine blades. Currently, Ni-based superalloys are the primary materials for these applications however; increases in strength and operating temperature are nearing their limits. A recent discovery in 2006 has shown that the Co-Al-W has the potential to replace Ni-based alloys, however development of this type of Co-base superalloys is in its infancy. Current work at northwestern seeks to increase grain boundary strength, and thus creep strength, through the addition of B and Zr. Development of Ni and Ti containing Co alloys taking place simultaneously to increase the operating temperature of the alloys. Scanning Electron Microscopy (SEM) and Atom-Probe Tomography (APT) are used to investigate the microstructure and composition characteristics of these alloys. Mechanical properties are being tested primarily in the form of high-temperature creep and compression testing.