About this Abstract |
Meeting |
MS&T22: Materials Science & Technology
|
Symposium
|
Alloy Phase Transformations at Elevated Temperatures
|
Presentation Title |
Microstructure and Mechanical Properties of W-free γ + γ' Co-based Superalloys with Ni, Cr, and Fe Additions |
Author(s) |
Brandon Ohl, Howard Stone, David Dunand |
On-Site Speaker (Planned) |
Brandon Ohl |
Abstract Scope |
The effects of adding Ni (0-30 at.%),Cr (4-8 at.%), and Fe (0-18 at.%) to a W-free, Co-based superalloy's phase evolution are investigated. Most alloys maintain a stable FCC + L12 microstructure upon aging 1000 h at 850ºC, with some formation of other intermetallic phases in alloys with high Fe and Cr. In addition to precipitate microscopy analysis as samples age, neutron diffraction and synchrotron X Ray diffraction are used to determine the γ/γ' lattice misfit, and differential scanning calorimetry is used to determine γ' solvus and γ solidus/liquidus temperatures. Microstructure is then connected to mechanical properties, as measured by compressive creep tests at 850ºC and by compressive yield measurements between room temperature and 950 ºC. |