|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Phase Transformations and Microstructural Evolution
||Phase Transformations and Structural Changes in Haynes 244, A New Ni Based Low CTE Alloy
||Jie Song, Robert Field, Cody Miller, Raj Banerjee, Doug Konitzer, Michael Kaufman
|On-Site Speaker (Planned)
Haynes 244 is a recently-developed, low CTE Ni-based superalloy that has many potential applications including seals and rings in gas turbine engines and interconnects in solid oxide fuel cells. The main strengthening phase in this alloy is Ni2(Mo,Cr) which, as will be shown, appears to form as small (10-200nm), metastable, coherent precipitates. In addition, three different grain boundary (GB) precipitates were characterized, some of which are unreported to our knowledge. Moreover, unusual precipitate free zones (PFZs) were observed after certain treatments. At 770°C, the PFZ appeared relatively large (~5 to 10 μm) after 16h but then decreased to around 2 μm after 64h. In contrast, the Ni2(Mo,Cr) precipitate size increased significantly during aging as expected. Finally, it will be shown that a two-step heat treatment can be used to produce fine (~300nm) and dense Ni2(Mo,Cr) precipitates in the matrix and small PFZs (~1 μm).
||Planned: A print-only volume