|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Characterization of Minerals, Metals, and Materials
||Microstructural Evolution of Single Ni2TiAl or Hierarchical NiAl/Ni2TiAl Precipitates in Fe-Ni-Al-Cr-Ti Ferritic Alloys during Thermal Treatment
||Gian Song, Yanfei Gao, Zhiqian Sun, Jonathan Poplawsky, Peter K. Liaw
|On-Site Speaker (Planned)
Microstructural formation and evolution of recently-developed Fe-Ni-Al-Cr-Ti alloys with superior creep resistance have been systematically investigated using transmission-electron microscopy, scanning-electron microscopy, and atom-probe tomography. These alloys were designed by adding 2 or 4 weight percent (wt. %) Ti into a NiAl-hardened ferritic alloy with a nominal composition of Fe-6.5Al-10Cr-10Ni-3.4Mo-0.25Zr-0.005B in wt. %. These alloys were subjected to a solution treatment at 1,473 K for 0.5 hour, followed by aging treatments at 973 K for 1 ~ 500 hours. These alloys show different precipitate structures (i.e., coherent cuboidal and semi-coherent polygonal precipitates) and microstructural evolution (structure, size, morphology, and distribution) during the heat-treatment. The formation of the different types of the precipitates, and their effects on the microstructural evolution are discussed, and the driving forces for these features are identified from the competition among interface energy and elastic interactions due to lattice misfit and interfacial dislocations.
||Planned: A print-only volume