Morphology Dependent of Flow Stress of Nickel-Based Superalloys in the Multi-Scale Crystal Plasticity Framework

Published

November 2, 2017

Author(s)

Shahriyar Keshavarz, Zara Molaeinia, Andrew C. Reid, Stephen A. Langer

Abstract

This paper develops a framework to obtain flow stress of Nickel-based superalloys as a function of gamma-gamma prime morphology. In general, the two-phase gamma-gamma prime morphology in Nickel-based superalloys can be divided into three variables including gamma prime shape, gamma prime volume fraction and gamma prime size in the sub-grain microstructure. In order to obtain the flow stress, non-Schmid crystal plasticity constitutive models at two length scales are employed and bridged through a homogenized multi-scale framework. The multi-scale framework includes two sub-grain and homogenized grain scales. For the sub-grain scale, a size-dependent, dislocation density-based finite element model (FEM) model of the representative volume element (RVE) with explicit depiction of the gamma-gamma prime morphology is developed as a building block for homogenization. For the next scale, an activation energy based crystal plasticity model is developed for homogenized single crystal of Ni-based superalloys for a large temperature range, and include orientation dependencies and tension-compression asymmetry. This homogenized model is used to obtain the morphology dependent of flow stress in nickel-based superalloys and can significantly expedite crystal plasticity FE simulations in polycrystalline microstructures as well as higher scales FE models in order to cast and design superalloys.

Citation

Elsevier

Pub Type

Journals

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Keywords

Flow stress, morphology, Ni-based superalloys, homogenization, crystal plasticity

Citation

Keshavarz, S. , Molaeinia, Z. , Reid, A. and Langer, S. (2017), Morphology Dependent of Flow Stress of Nickel-Based Superalloys in the Multi-Scale Crystal Plasticity Framework, Elsevier, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=921620 (Accessed October 10, 2025)