The influence of microstructure on surface strain distributions in a nickel micro-tension specimen

Abstract

This work presents an integrated experimental and modeling approach for examining the deformation of a pure nickel polycrystal utilizing micro-mechanical testing and a crystal-based elasto-viscoplastic finite-element model (CPFEM). The objective is to study the influence of microstructure on the heterogeneous deformation in polycrystalline materials, and to utilize a modeling framework to explore aspects of the deformation that are difficult or impossible to measure experimentally. To accomplish this, a micro-tension specimen containing 259 grains was created from a pure nickel foil material and deformed in uniaxial tension. After the deformation, the specimen was destructively serial sectioned in concert with electron back scattering diffraction, and these data were used to instantiate a CPFEM simulation. The material parameters in the CPFEM model were calibrated by matching the experimental macroscopic stress-strain response of the micro-tension specimen, and then the simulation results were compared with experimental surface deformations measured with digital image correlation. After validating the simulation results by comparing measured and predicted surface strain distributions, a parametric study of the influence of both crystallographic texture and grain morphology is presented to better understand the influence of microstructure on the development of heterogeneous deformation in the pure nickel polycrystalline material.

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Emerging Science and Research Opportunities for Metals and Metallic Nanostructures

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Combined near- and far-field high-energy diffraction microscopy dataset for Ti-7Al tensile specimen elastically loaded in situ

“…This offers a powerful tool to characterize the internal structure and mechanical behavior of deformable solids, which can be used to instantiate, and then later validate, micro-and meso-scale models such as crystal plasticity finite element modeling (CPFEM) [4][5][6]. The dataset presented in this paper represents concurrently collected near-field HEDM (nf-HEDM) [7][8][9] and far-field HEDM (ff-HEDM) measurements [10][11][12][13]; a first analysis of these data is contained in [14].…”