Diffraction and single-crystal elastic constants of Inconel 625 at room and elevated temperatures determined by neutron diffraction

Abstract

In this work, diffraction and single-crystal elastic constants of Inconel 625 have been determined by means of in situ loading at room and elevated temperatures using time-of-flight neutron diffraction. Theoretical models proposed by Voigt, Reuss, and Kroner were used to determine single-crystal elastic constants from measured diffraction elastic constants, with the Kroner model having the best ability to capture experimental data. The magnitude of singlecrystal elastic moduli, computed from single-crystal elastic constants, decreases and the single crystal anisotropy increases as temperature increases, indicating the importance of texture in affecting macroscopic stress at elevated temperatures. The experimental data reported here are of great importance in understanding additive manufacturing of metallic components, in which diffraction elastic constants are required for computing residual stresses from residual lattice strains measured using neutron diffraction, which can be used to validate thermo-mechanical models of additive manufacturing, while single-crystal elastic constants can be used in crystal plasticity modeling, for example, to understand mechanical deformation behavior of additively manufactured components.

Temperature dependence of elastic and plastic deformation behavior of a refractory high-entropy alloy

“…The magnitudes of single-crystal and macroscopic elastic moduli, obtained by in situ neutron experiments and resonant ultrasound spectroscopy (RUS), respectively, are compared to theoretical calculations, including first-principles calculations and machine learning (ML) approaches. Furthermore, it is found that the present NbTaTiV refractory HEA indicates the lack of strong temperature-dependent elastic anisotropic deformation behavior at elevated temperatures, which is atypical elastic deformation behavior, compared to other conventional metallic materials (12)(13)(14)(15).…”

Absence of dynamic strain aging in an additively manufactured nickel-base superalloy

“…Each subset of the grains is designated here as < hkl >//LD where < hkl > represents the plane normal of the grains that are aligned in the LD. The effective stress along the LD, , acting locally on the < hkl >//LD grains, can be approximated by the < hkl >-dependent lattice strain in the LD, , given as 41 , where is the hkl -dependent Young’s modulus of the single crystal, which for these samples was reported elsewhere 42 .…”

Elastic Residual Strain and Stress Measurements and Corresponding Part Deflections of 3D Additive Manufacturing Builds of IN625 AM-Bench Artifacts Using Neutron Diffraction, Synchrotron X-Ray Diffraction, and Contour Method

“…Figure 5 defines the neutron diffraction angles. Here, the diffraction elastic constants are calculated from the single crystal elastic constants of IN625: C11 = 243.6 GPa, C12 = 156.7 GPa, and C44 = 117.8 GPa [10] using IsoDEC [11]. For each location where "" = 0 applies, there are three equations of this kind (one d-spacing for each orientation measured) forming a system that can be solved for the three unknowns ( %% , :: , and d0).…”