Changes In Crystallographic Texture Research Articles

On the O2 "Surfactant" Effect during Ag/SiO2 Magnetron Sputtering Deposition: The Point of View of In Situ and Real-Time Measurements.

The use of gaseous species has been proposed in the literature to counteract the three-dimensional growth tendency of noble metals on dielectric substrates and favor an earlier percolation without compromising electrical properties. This "surfactant" effect is rationalized herein in the case of O2 presence during magnetron sputtering deposition of Ag films on SiO2. In situ and real-time techniques (X-ray photoemission, film resistivity, UV-visible optical spectroscopy) and ex situ characterizations (X-ray diffraction and transmission electron microscopy) were combined to scrutinize the impact of O2 addition in the gas flow (%O2), revealing three regimes of evolution of film resistivity, morphology, structure, and chemical composition. At low oxygen flow conditions (%O2 < 4), the observed drastic decrease of the percolation threshold is assigned to a combination of (i) a change in nanoparticle density, wetting, and crystallographic texture and (ii) a delayed coalescence effect. The driving force is ascribed to the presence of specific adsorbed oxygen moieties, the nature of which starts evolving at intermediate oxygen flow conditions (10 ≤ %O2 < 20). At high oxygen flow (20 ≤ %O2 < 40), the found detrimental impact on film resistivity is assigned to an actual oxidation in the form of a Ag2O-like poorly crystallized compound. For all %O2, a composition gradient is observed across the film thickness, with a more metallic Ag at the substrate interface. A correlation between percolation and the nature of the detected O moieties is observed. In parallel to an oxygen spillover mechanism, this gradient can be explained by the competition between different surface processes occurring before percolation, namely, aggregation, metal oxidation, and substrate reactivity. Such findings pave the way to a rational use of O2 as a modifier for Ag growth.

Enhancement of microstructure, micro-texture, and mechanical properties of Al6061 friction stir welds using the developed static shoulder welding tool

Dissolution of strengthening precipitates and grain coarsening are the key factors that dictate the mechanical properties of heat-treatable aluminium alloys. In this study, a feasible method of static shoulder friction stir welding (SSFSW) is used to reduce these adverse effects. A novel static shoulder friction welding tool is developed here in this study by incorporating rotating and non-rotating shoulders in a single tool. The effectiveness of the tool was evaluated by welding Al6061 plates under various conditions, such as conventional friction stir welding (CFSW), underwater friction stir welding (UWFSW), and SSFSW. The evolution of crystallographic texture and microstructural changes during the process is studied using electron back scattered diffraction and transmission electron microscopy. The results showed that SSFSW reduced grain size by 37% compared to UWFSW at the centre of the stir zone and increased the yield strength by 22.8% compared to CFSW. In addition, SSFSW showed a strong presence of γ-fibre, indicating improved formability and a 7.2% improvement in joint efficiency in terms of ultimate tensile strength due to a higher fraction of precipitates and higher dislocation density.

Finite element analysis using elasto-visco-plastic self-consistent polycrystal model for E-form Mg sheet subjected to bending

The mechanical behavior of a magnesium alloy E-form under bending was investigated using the elasto-visco-plastic polycrystal model (ΔEVPSC) and its finite element (FE) implementation (ΔEVPSC-FE) developed in Jeong et al. and Jeong and Tomé. The crystallographic orientation distribution (COD) obtained from X-ray diffraction was used to represent the initial texture, and the Voce hardening parameters were calibrated by fitting the uniaxial tension and the compression flow stress curves. A quasi-static FE analysis of a miniaturized V-bending operation was conducted using the ΔEVPSC-FE model. The bending induced an inhomogeneous stress response along the through-thickness and the lateral directions, which was well captured by the model. Moreover, the predictive capability of the model was validated by comparing with various experimental results such as (1) force vs. displacement curves; (2) the through-thickness variations in the twin volume fraction; and (3) the changes in crystallographic texture as a function of displacement. Additional bending simulation was performed using an isotropic texture, the result of which suggests that the potential improvement in bendability of the magnesium alloy is attainable by weakening the initial texture. Moreover, the simulation results imply that the crystallographic texture, which may affect the twin activation across the thickness direction, plays a significant role in the shifting direction of the neutral layer.

TEMPERATURE DEPENDENCE OF ACOUSTIC BIREFRINGENCE OF SHEAR ELASTIC WAVES IN POLYCRYSTALLINE ALUMINUM

The article presents the results of a study of the temperature dependences of the shear elastic waves velocity of polycrystalline aluminum alloy AD0 in the temperature range from 20 °C to 45 °C. For the studied material the temperature dependence of the acoustic birefringence parameter characterizing the a shear ultrasonic wave splitting into two orthogonally polarized waves propagating at different velocities is determined. The calculation of the acoustic birefringence parameter was carried out according to the data of the propagation time precision measurement of shear elastic waves (the measurement error of the propagation time is 1-2 ns), polarized along and across the direction of rolling. Theoretical studies have shown that for materials with weak anisotropy, the temperature dependence of the acoustic birefringence parameter is mainly related to the influence of temperature on the elastic anisotropy of the crystals that make up the polycrystalline material and the characteristic of the crystallographic texture – the coefficient of the orientation distribution function W420. Corrections to the value of the birefringence parameter with temperature change are given. It was experimentally obtained that the acoustic birefringence parameter increases by 9% with increasing temperature, which must be taken into account by using it as a diagnostic parameter to evaluation changes in the characteristics of static and fatigue strength. An algorithm is proposed for estimating the prediction of the temperature dependence of the acoustic birefringence parameter of a single-phase material when the crystallographic texture changes as a result of plastic deformation, for example. A good coincidence of the predicted temperature dependence of the acoustic birefringence parameter with the experimental one was obtained – the deviation error of the calculated curve from the experimental one was 0.2–2% in the temperature range of 20 °С to 45 °С.

An analysis of crystallographic texture and residual stresses of aluminium alloy RSA-501 after selected processes of twist extrusion (TE)

This study presents the residual stress analysis for the twist extrusion (TE) process after the experiment and numerical simulation and the analysis of the crystallographic texture changes and changes in hardness before and after the TE process for an RSA-501 aluminium alloy (Al; Mg5%; Mn1.5%; Sc0.8%; Zr0.4%).Crystallographic textures were obtained with the PANAlytical Empyrean X-ray diffractometer. The stresses were measured by applying the X-ray method with the use of using the PROTO iXRD diffractometer.The use of severe plastic deformation processes in the mass of the material leads to a significant change difference in the stress distribution in the workpiece and a change in texture compared to the reference material. The stress distribution in the sample cross-section and stress values varied and depended on the stage of the twisting process to which the surface was subjected. The highest stress (about 600 MPa) appears at the peaks of the front surface when exiting the twist area die TE. Higher stress values at the edges of the specimen are caused by friction (deformation) of the material against the die surface. The TE process strengthened the highest crystallographic texture background level was 49%.The conducted tests and the obtained results allow the determination of the process parameters and critical areas of the sample by carrying out a numerical simulation.Microhardness increases due to the TE process and the largest values were observed at the edges. This phenomenon is confirmed by the numerical simulation results presented in this paper.

Influence of Ultrafine-Grained Microstructure and Texture Evolution of ECAPed ZK30 Magnesium Alloy on the Corrosion Behavior in Different Corrosive Agents.

Magnesium-Zinc-Zirconium (Mg-Zn-Zr) alloys have caught considerable attention in medical applications where biodegradability is critical. The combination of their good biocompatibility, improved strength, and low cytotoxicity makes them great candidates for medical implants. This research investigation is focused on providing further insight into the effects of equal channel angular processing (ECAP) on the corrosion behavior, microstructure evolution, and mechanical properties of a biodegradable ZK30 alloy. Billets of Mg-3Zn-0.6 Zr (ZK30) alloy were processed through ECAP up to 4 passes of route Bc (rotating the billets 90° in the same direction between the subsequent passes) at 250 °C. Electron back-scatter diffraction (EBSD) was utilized to investigate the microstructural evolution as well as the crystallographic texture. Several electrochemical measurements were carried out on both a simulated body fluid and a 3.5% sodium chloride (NaCl) solution. Mechanical properties such as Vicker’s hardness and tensile properties were also assessed. The as-annealed (AA) microstructure was dominated by equiaxed coarse recrystallized grains with an average grain size of 26.69 µm. After processing, a geometric grain subdivision took place due to the severe plastic deformation. Processed samples were characterized by grain refinement and high density of substructures. The 4-passes sample experienced a reduction in the grain size by 92.8% compared with its AA counterpart. The fraction of high-angle grain boundaries increased significantly after 4-passes compared to the 1-pass processed sample. With regards to the crystallographic texture, the AA condition had its {0001} basal planes mostly oriented parallel to the transversal direction. On the other hand, ECAP processing resulted in crystallographic texture changes, such as the shifting of the ZK30 shear plane to be aligned at 45° relative to the extrusion direction (ED). Furthermore, the maximum texture intensity was reduced from 14 times random (AA billets) to 8 times random after ECAP processing through 4-passes. The corrosion rate of the 4-passes sample was tremendously reduced by 99% and 45.25% compared with its AA counterpart in the simulated body fluid and the NaCl solution, respectively. The pitting corrosion resistance of ZK30 showed notable improvements in the simulated body fluid by 471.66% and 352% during processing through 1-pass and 4-passes, respectively, compared with the 3.5% NaCl findings. Finally, significant improvements in the tensile strength, hardness, and ductility were also achieved.

Effect of Fiber Orientation on Microstructure and Texture Evolution During the Cold‐Rolling of Al–Mg–Si Alloy

A material with a strong double fibrous texture is subjected to rolling with various deformation paths—unidirectionally and with 90° rotations about the normal direction (cross‐rolling). Additionally, the orientation of the initial fiber is manipulated to force unlikely grain rotations. The purpose of these procedures is to study the dependence between crystallographic and morphological texture changes caused by the rolling. Microstructure observations show that deformation mechanism responsible for the final microstructure depends on the initial fiber orientation. The crystallographic texture is related to the deformation mode and leads toward expected orientations; however, the initial grain boundaries alignment has a strong impact on the final microstructure. Unidirectional rolling results in typical orientations along the β‐fiber in all investigated cases. The texture created during the more complex deformation path with inset rotations follows the geometrical constraints for fourfold symmetry, even if this required unlikely rotations toward the α‐fiber.

Non-destructive detection of machining-induced white layers through grain size and crystallographic texture-sensitive methods

Detection of machining-induced white layers is currently a destructive inspection process with a form of cross-sectional microscopy required. This paper, therefore, reports on the development of a novel non-destructive inspection method for detecting white layers using grain size-sensitive and crystallographic texture-sensitive techniques. It is shown that x-ray diffraction can be used to detect white layers as thin as 5 μm in Ti-6Al-4 V through measurement of diffraction peak breadths and diffraction peak intensities, due to the influence of the sub 100 nm grain size and high lattice strain in the white layer, as well as the strong crystallographic texture in this titanium alloy. Compared to the existing optical microscopy inspection method, which can take days due to the number of steps involved, the x-ray diffraction peak breadth method offers non-destructive white layer detection in a matter of minutes at a resolution of 5 μm or less that competes directly with the optical method. Spatially resolved acoustic spectroscopy, a laser-generated ultrasonic surface acoustic wave detection method, can also be used to identify anomalous surfaces, containing a white layer or swept grain material, due to its sensitivity to the crystallographic texture changes that arise in severely plastically deformed Ti-6Al-4V as in Titanium with 6 % Aluminium and 4% Vanadium.

Influence of temperature on microstructure, crystallographic texture and mechanical properties of EN AW 6016 alloy during plane strain compression

The use of Al-Mg-Si alloys has increased significantly in automobile and aerospace industries during the past few decades, and improving the formability of the alloy has always been under focus for various applications. Plane strain compression (PSC) tests have been conducted for EN AW 6016 naturally aged (T4) alloy at different temperatures (room temperature, 150 °C and 250 °C), at a particular strain rate (0.1 s−1). The samples exhibited a decreasing pattern of flow properties (yield strength and work hardening rate) and increasing anisotropy with temperature. The reasons for the changes in flow behaviour with temperature were explained with the help of finite element modelling (FEM). Work hardening behaviour at different stages of stress was investigated and correlated with the microstructure. Microstructural characterization has been performed using electron backscattered diffraction (EBSD), and scanning electron microscopy (SEM) based Gallium Enhanced Microscopy (GEM) techniques with an aim to reveal the substructure development due to imposed deformation at different temperatures. Calculation of macro-texture was performed using X-Ray Diffraction (XRD) technique in order to observe the changes in crystallographic texture before and after deformation. A mathematical comparative analysis indicates the contribution of different texture components towards the variation in flow properties. Considerable increment in volume fraction of Goss texture at 250 °C has been found to have a significant impact on formability.

Microstructure and Crystallographic Texture Changes under Torsion Loading of Pearlitic Steel Strips

Cold-drawn pearlitic steel strips exhibit a great combination of strength and ductility and are widely used in many engineering applications. Some of these applications require further mechanical conformation for the final use. An analysis of the microstructure and the change in crystallographic texture when strips are subjected to torsion processes necessary for some applications was made in the current study. It was shown that the formation of the wavy pearlite morphology associated with the fiber texture parallel to the drawing axis could improve fatigue damage. Extreme dislocation densities and crystallographic defects induced by torsion enhanced the formation of ultrafine ferritic grains accompanied by partial cementite decomposition. The relationship between ferrite and cementite interfaces successfully simulated using the Shackleton model.

Microstructural characterization of laser surface-melted Inconel 718

In the present study, a detailed study of the effect of laser parameters on microstructure and phases of the laser surface-melted (using 2 kW continuous wave Yb-fibre laser) Inconel 718 has been carried out. Surface melting has been conducted with a power of 400 watts, scan speed of 500, 750, and 1000 mm/min and with a spot diameter of 3 mm. After laser surface melting, the microstructures, phase, surface roughness and crystallographic orientation (texture) of the melt zone has been carried out. There is refinement of microstructure and change in crystallographic texture which varied with process parameters. The effect of process parameters on the microhardness of the melt zone has been studied in detail.

Forming Limit Diagrams of Low-Carbon Steels Obtained Using Digital Image Correlation Technique and Enhanced Formability Predictions Incorporating Microstructural Developments

In the present work, drawing quality (DQ) and interstitial-free (IF) steel sheets were subjected to limiting dome height tests for determining strain-based forming limit diagrams (FLDs) experimentally and effect of dynamic (variable) material properties, such as work hardening ‘n’ and plastic anisotropy ( $$\bar{r}$$ ), on FLDs has been studied and simulated by PAMSTAMP™ finite element software. Dot prints on the steel specimens and an efficient optical strain measurement system GOM™ which works on the digital image correlation technique principle were used to measure limiting strains accurately instead of conventional circle grid analysis technique and strain measurement by traveling microscope. The dynamic (variable) material properties (n) and ( $$\bar{r}$$ ) were estimated by studying the microstructural developments in terms of changes in grain average misorientation and crystallographic texture, respectively, at different strains and strain paths, during deformation. In our proposed work, a novel technique of incorporating dynamic (variable) material properties (n and $$\bar{r}$$ ) in FE simulations was carried out during FLDs predictions. Though marginal but improved predictions in FLDs were observed in both IF and DQ steels. In addition to strain-based FLDs, stress-based FLDs were also determined for both grades. Interestingly, in both cases it was noticed that IF steel had higher formability than DQ steel.

Real-time observation of twinning-detwinning in shock-compressed magnesium via time-resolved in situ synchrotron XRD experiments

Both engineered and natural materials may be subjected to extremes of elevated pressure, temperature, and strain rate due to shock loading; examples include ballistic impact of projectiles on armor, planetary impacts, and high-speed machining operations. Experimental techniques for ascertaining the macroscopic response of materials to shock loading are well established, but insight into fundamental mechanisms of deformation requires the ability to characterize the evolution of microstructure in real time. Experiments in which specimens are recovered and characterized after shock loading have been widely used to understand structure-property relationships. But these shock recovery experiments only reveal information at the end state of the material, from which the evolution of the structure during unloading must be inferred. There is always the possibility that the structure of the material continues to evolve during unloading, leading to a potential misunderstanding of the structural evolution during shock compression and release. In this paper we describe the results of shock recovery and time-resolved in situ x-ray diffraction studies of deformation twinning in an extruded fine-grained AMX602 magnesium alloy. The samples were shock compressed along the plate normal and extrusion directions, then released back to ambient conditions. Analysis of the microstructure before and after shock loading indicates a substantial change in crystallographic texture reflecting substantial deformation twinning. Texture evolution from in situ synchrotron x-ray diffraction measurements show significant twinning during shock compression followed by detwinning during stress release. These results not only provide insight into the complex twinning-detwinning behavior of this particular alloy, but also illustrate the utility of in situ characterization for bridging the knowledge gap between shock recovery experiments and the transient behavior of materials during shock loading more generally.

Plastic Flow During Hot Working of Ti-7Al

Plastic flow during hot working of Ti-7Al with an equiaxed-α (fully-recrystallized) starting microstructure was quantified and interpreted via hot compression testing, metallographic/texture characterization, and internal-state-variable modeling. Isothermal, hot compression tests were conducted to axial strains of 0.2, 0.5, or 1.0 at temperatures of 1089 K, 1172 K, and 1227 K (816 °C, 899 °C, and 954 °C) and a constant true rate of 0.1 s−1. After correcting for deformation heating effects, all of the corresponding flow curves exhibited a high level of flow hardening at strains between 0 and ~ 0.2 followed by moderate hardening. Subsequent microstructure analysis via polarized-light, optical microscopy and electron-backscatter diffraction in a scanning-electron microscope revealed wrought grains containing substantial orientation gradients, small fractions (≤ 0.1) of very fine recrystallized grains at the initial grain boundaries, and small fractions of deformation twins. In view of the absence of discontinuous dynamic recrystallization except at large strains/high temperatures, viscoplastic, self-consistent (VPSC) crystal-plasticity analysis was performed to quantify the effect of crystallographic texture changes on plastic flow. For this purpose, simulations were done assuming (1) deformation via slip alone or slip plus twinning and (2) an absence of strain hardening. The VPSC simulations revealed similar texture hardening for both types of assumed deformation modes. Correction of the flow curves for such texture hardening resulted in material flow response comprising an initial strain-hardening transient followed by steady-state flow. The latter curves were analyzed in terms of the Yoshie–Laasraoui–Jonas single-state-variable formulation. The fitted dynamic-recovery and strain-hardening parameters were comparable to those found for fcc metals at hot working temperatures.

Experimental investigation of the dynamic impact responses of as-cast and homogenized A535 aluminum alloy

Aluminum A535 alloy plates were received in the as-cast condition. Some specimens cut from the cast plates were homogenized at 400 °C for 5 h and then quenched in water to room temperature. SEM, EDS, and EBSD analyses of ground and polished specimens show that in addition to a change in crystallographic texture of the A535 alloy, significant reduction in pores and removal of microsegregation occurred during homogenization heat-treatment of the as-cast specimens. Homogenizing heat treatment also decreased the average grain size of the alloy by discontinuous static recrystallization mechanism. The dynamic impact responses of as-cast and homogenized aluminum A535 alloy were experimentally determined using the split Hopkinson pressure bar system. At a true strain rate between 4 × 103 and 14.2 × 103 s-1, the homogenized specimens exhibited better dynamic mechanical strength and ductility than the as-cast specimens. Higher strength in the homogenized specimen is attributed to higher grain boundary area and stronger evolution of CD||[110] grains than in the as-cast specimens. On the other hand, severe mechanical damage such as loss of roundness of cylindrical specimen, severe micro-cracks and formation of adiabatic shear bands occurred more in homogenized specimens than in as-cast specimens. Using the electron back-scattered diffraction technique, activation of multiple dynamic recrystallization (DRX) mechanisms and the role of crystallographic texture were observed in the investigated alloy. While continuous DRX occurred at the center of the deformed specimens, discontinuous DRX occurred homogenously on the entire polished surface of the specimen at particle sites. Microsegregation and texture-related conditions enhanced DRX more readily in as-cast specimens than in the homogenized specimens. The mode of dynamic failure and fracture in the investigated alloy deviates from those reported in the literature for wrought alloys.

Cold Rotary Forging of Inconel 718

The present work includes an in-depth study of microstructure and mechanical property development in a cold rotary forged component manufactured from Inconel 718 alloy. This work is pioneering in that there is no detailed study available in the literature focussing on cold rotary forging of Inconel 718. A tubular preform of 6 mm wall thickness was cold rotary forged into a 90 degree flange part followed by annealing with double aging. The present study provides a thorough analysis of microstructure, hardness and surface roughness evolution from as-received to final cold rotary forged and heat-treated condition including crystallographic texture changes occurring at different stages. The solution-annealed condition of the preform was found to be most suitable for cold rotary forging of Inconel 718. An annealing treatment followed by double-aging imparted desired properties such as homogeneous microstructure, uniform hardness distribution and improved surface roughness into the cold rotary forged Inconel 718 flange. The cold rotary forging can be a cost-effective route for manufacture of axisymmetric components with high material yield and low buy-to-fly ratio for expensive materials such as Inconel 718.

Effect of Microstructure and Texture Evolution During Variable Gauge Rolling on Mechanical Properties of Tailor Rolled Blanks

In this study, anisotropic elastic and plastic mechanical properties of a tailor rolled blank (TRB) with thickness ratio of 0.52 (1 mm/1.9 mm), have been fully studied. To gain a deeper insight into anisotropic mechanical behavior of the studied TRB, continuous changes in microstructure and crystallographic texture of a dual phase steel caused by variable gauge rolling (VGR) were investigated on several points (on RD–ND plane) along longitudinal direction with the aid of EBSD observations. Analysis of grain boundary (GB) maps revealed that ferrite grain refinement is occurred during VGR so that the average ferrite grain size decreases from 4.1 µm for the thicker side to 2.2 µm for the thinner side. Furthermore, it was found out that substructure density is more intense within smaller ferrite grains. Evaluation of inverse pole figures as well as orientation distribution function maps showed that texture of thicker side comprises {001}〈110〉 and {112}〈110〉 components along $$ \alpha $$ -fiber. In addition, it was revealed that orientations of {111}〈110〉 and {111}〈112〉 along $$ \gamma $$ -fiber strengthen along VGR direction by further increase in thickness reduction near thinner side. Accordingly, unprecedented gradual changes in mechanical properties with respect to these changes in microstructure and texture, were obtained. Finally, the correlation between in-plane anisotropic mechanical properties [Young’s modulus (E), yield stress (YS), ultimate tensile stress (UTS) and total elongation] of the studied tailor rolled blank with microstructure and deformation texture was interpreted.

The influence of surface pre-twinning on the friction and wear performance of an AZ31B Mg alloy

Twinning is an important mode in plastic deformation of hexagonal close-packed magnesium (Mg) alloys that are promising lightweight structural metals. Recent studies show that the hardness, strength, and stretch formability of Mg alloys can be improved by pre-twinning. However, how twinning and associated microstructure influence the tribological properties of Mg alloys have not been studied systematically. In this work, a gradient twin microstructure in which the density of twins decreases with depth was introduced to an AZ31B Mg alloy plate by laser shock peening. Then sliding tests were performed on surfaces with varying twin volume fraction (TVF) under dry condition. The results shown that both the coefficient of friction (COF) and wear rate decrease with the increase of TVF. A possible mechanism responsible for the effect of surface pre-twinning on the tribo-performance of Mg alloys is proposed. In specific, it is discussed that the improved tribo-performance of Mg alloys by pre-twinning are attributed to the twinning-induced hardening effect, twin growth and saturation phenomenon, and twinning-induced surface crystallographic texture change during sliding. We envision the results in the present study can offer new insights on the designing and developing Mg alloys towards enhanced tribological performance.

Simulation of crystallographic changes during recrystallization by one-dimensional cellular automaton

Cellular automata are one of the most frequently used methods to simulate the recrystallization process. The cellular automata give the complex nature of this process with a simple implementation. One of the greatest effort in this field is to calculate the changes in crystallographic texture. One-dimensional cellular automata are introduced to calculate the kinetics of recrystallization. This study introduces a simple method which makes it possible to incorporate the texture components to the calculations.

Early detection of fracture failure in SLM AM tension testing with Talbot-Lau neutron interferometry

Tensile stress in selective laser melted (SLM) stainless steel 316 (SS316) bars was studied with neutron imaging methods for measurement of attenuation, scattering, and diffraction. The hypotheses for stress failure includes modifications to both the grain structure and residual porosity. Neutron Bragg edge imaging showed a change in crystallographic structure and/or texture at a pre-existing fracture, but did not provide evidence for presumptive crack formation. A Talbot-Lau grating-based neutron interferometer yielded better than 100 μm spatial resolution for the attenuation images and was tuned to an autocorrelation scattering length of 1.97 μm for the dark-field (scattering) images. The interferometry imaging was performed with samples parallel and perpendicular to the linear grating, allowing assessment of scattering along and perpendicular to the additive manufacturing build direction. In the 3D tomography dark-field volume of a tensile stressed bar, features were observed that suggested possible sites of crack formation. The features were quantified with line probes and found to be reproducible over three tomography experiments. After imaging, the half-stressed bar was pulled to failure; the fracture point is correlated with a feature in the line probe having enhanced neutron scattering. Neutron interferometry, particularly the dark-field imaging modality, emerges as a powerful non-destructive method for detecting early crack formation in additive manufactured components.