About this Abstract |
Meeting |
2021 TMS Annual Meeting & Exhibition
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Symposium
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Materials for High Temperature Applications: Next Generation Superalloys and Beyond
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Presentation Title |
Compositionally Graded Nanosize Precipitates at Grain Boundaries of Directionally Solidified Nickel Based (GTD444) Superalloy |
Author(s) |
Richa Gupta, M.J.N.V. Prasad, Prita Pant |
On-Site Speaker (Planned) |
Richa Gupta |
Abstract Scope |
Minor addition of boron as a grain boundary strengthener improves the creep rupture properties of Ni-based superalloys. However, the existence of boron in the multicomponent system remains questionable. The role of boron in altering the grain boundary chemistry has been investigated in DS GTD444. DS GTD444 is a grade of General Electric (GE) suitable for later stage gas turbine buckets. The samples were characterized extensively by time of flight-secondary ion mass spectrometry (ToF-SIMS), transmission electron microscopy (TEM) in conjunction with energy-dispersive X-ray spectroscopy (EDS). Here we report first time the presence of compositionally graded nanosize boride precipitates in a superalloy system. The investigation suggests that most of boron present at the γ-γ' interface lies along grain boundary in the form of nanosize (~80-90 nm), (Cr, W, and Mo) based metal borides. The presence of borides could indirectly suppress the agglomeration of reported M23C6 carbides at grain boundaries of DS GTD444. |
Proceedings Inclusion? |
Planned: |