CALPHAD informed design of multicomponent CoNiCr-based superalloys exhibiting large lattice misfit and high yield stress

Liang Z, Neumeier S, Rao Z, Göken M, Pyczak F (2022)

Publication Type: Journal article

Publication year: 2022

Journal

Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing Elsevier

Book Volume: 854

Article Number: 143798

DOI: 10.1016/j.msea.2022.143798

Abstract

Usually, Co-based superalloys contain a high fraction of W and/or Mo. The refractory elements stabilize the precipitate phase, but cause a high density. In this work, new L12-phase hardened, low-density CoNiCr-based superalloys were developed with the assistance of CALPHAD calculations. Several alloys were studied experimentally and their microstructures, elemental distributions, lattice parameters and the lattice misfit between the γ and γ′ phases were evaluated using scanning electron microscopy, transmission electron microscopy, atom probe tomography and high energy X-ray diffraction. The alloys exhibit a very high misfit, good phase stability and excellent mechanical strength. It was found by hardness tests that a two-step heat treatment improves the strength of the new alloys even further. In comparison with conventional Co-based superalloys, Co–Al–W based superalloys and Co–Ti based superalloys, as well as Ni-based superalloys, i.e. Udimet 720Li, they have a low mass density and high yield stress. They also overcome the problem of a generally low lattice misfit of previous L12-phase hardened CoNiCr-based superalloys with high Ni and Cr contents. As a result, they show cuboidal-shaped precipitates similar to Co–Al–W and Co–Al–Mo based superalloys.

Authors with CRIS profile

Steffen Neumeier Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften) Mathias Göken Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften)

Involved external institutions

Helmholtz-Zentrum Hereon DE Germany (DE) Max-Planck-Institut für Eisenforschung GmbH (MPIE) / Max Planck Institute for Iron Research DE Germany (DE)

How to cite

APA:

Liang, Z., Neumeier, S., Rao, Z., Göken, M., & Pyczak, F. (2022). CALPHAD informed design of multicomponent CoNiCr-based superalloys exhibiting large lattice misfit and high yield stress. Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing, 854. https://dx.doi.org/10.1016/j.msea.2022.143798

MLA:

Liang, Zhida, et al. "CALPHAD informed design of multicomponent CoNiCr-based superalloys exhibiting large lattice misfit and high yield stress." Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing 854 (2022).

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