Creep Behavior of a High-$$\gamma^{\prime}$$ Ni-Based Superalloy Fabricated via Electron Beam Melting

Autor: Obed D. Acevedo, Yousub Lee, Donovan N. Leonard, Michael M. Kirka, Sean Yoder, Patxi Fernandez-Zelaia
Rok vydání: 2021
Předmět:
Zdroj: Metallurgical and Materials Transactions A. 52:574-590
ISSN: 1543-1940
1073-5623
DOI: 10.1007/s11661-020-06095-3
Popis: Additive manufacturing enables the fabrication of complex engineering components previously inaccessible through traditional processes. Nickel-base superalloys with large $$\gamma^{\prime}$$ volume fraction are typically considered non-weldable and therefore exhibit a propensity for cracking during the fusion process. These crack-prone materials, however, are of great importance in gas turbine engines due to their excellent high temperature creep resistance. In this study we investigate the creep behavior of IN738LC produced by the electron beam melting process. We find that with appropriate post-build heat treatment the creep response of material oriented in the build direction exhibits deformation and rupture behavior comparable to that of conventionally cast IN738 & IN738LC. In the transverse direction properties fall below the expected cast behavior, however, we argue this is likely due to differences in grain scale and crystallographic texture. It may be possible to coarsen the grain morphology with appropriate process-parameter optimization in order to reduce the severity of intergranular fracture in the transverse direction. These results illustrate that high temperature properties exhibited by additively manufactured IN738LC are suitable for the hot section of gas turbine engines.
Databáze: OpenAIRE
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