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The hydrogen embrittlement behavior of a prerolled Fe–15Mn–0.65C–2Al–2Si high‐Mn steel with various cut‐edge properties is studied via hydrogen precharging and slow strain rate test. In the presence of hydrogen, samples prepared by laser cutting under atmosphere of N2 exhibit the best total elongation at about 39%. Press blanking produces severe shear deformation, tensile residual stresses, and strain‐induced martensite, resulting in a high risk to hydrogen‐induced cracking. With compressive residual stresses produced from waterjet, corresponding samples exhibit the lowest elongation loss against hydrogen. Despite hydrogen charging, the fracture surfaces show transgranular quasi‐cleavage features, for which mechanical twinning from prerolling plays a critical role. The hydrogen‐enhanced decohesion mechanism accounts for cleavage fracture since hydrogen segregation reduces cohesive stress at twin boundaries. [ABSTRACT FROM AUTHOR]

Slow‐cooled CF8M duplex stainless steel is used for critical parts of the primary coolant pipes of nuclear reactors. This steel can endure severe service conditions, but it tends to become more brittle upon very long‐term aging (tens of years). Therefore, it is essential to understand its specific microstructure and temporal evolution. As revealed by electron backscatter diffraction (EBSD) analyses, the microstructure consists of millimetre‐scale ferritic grains within which austenite lath packets have grown with preferred crystallographic orientations concerning the parent ferritic phase far from the ferrite grain boundaries. In these lath packets where the austenite phase is nucleated, the lath morphology and crystal orientation accommodate the two ferrite orientations. Globally, the Pitsch orientation relationship appears to display the best agreement with the experimental data compared with other classical relationships. The austenite lath packets are parallel plate‐shaped laths, characterized by their normal n. A novel methodology is introduced to elucidate the expected relationship between n and the crystallographic orientation given the coarse interfaces, even though n is only partly known from the observation surface, in contrast to the 3D crystal orientations measured by EBSD. The distribution of retrieved normals n is shown to be concentrated over a set of discrete orientations. Assuming that the ferrite and austenite obey the Pitsch orientation relationship, the determined lath normals are close to an invariant direction of the parent phase given by the same orientation relationship. [ABSTRACT FROM AUTHOR]

Disentangling nucleation and growth in materials that crystallize on the nanosecond time scale is experimentally quite challenging since the relevant processes also take place on very small, i.e., sub‐micrometer length scales. Phase change materials are bad glass formers, which often crystallize rapidly. Here systematic changes in crystallization kinetics are shown in pseudo‐binary compounds of GeTe and Sb2Te3 and related solids subjected to short laser pulses. Upon systematic changes in stoichiometry, the speed of crystallization changes by three orders of magnitude concomitantly with pronounced changes in stochasticity. Resolving individual grains with electron backscatter diffraction (EBSD) permits to disentangle of the process of nucleation and growth. From these experiments, supported by multiphysics simulations of crystallization, it can be concluded that high crystallization speeds with small stochasticity characterize phase change materials with fast nucleation, while compounds that nucleate slowly crystallize much more stochastically. [ABSTRACT FROM AUTHOR]

This study explored the effect of friction stir processing (FSP) on tungsten inert gas (TIG)-welded AA6061-T6 and AA7075-T6 joints by utilizing three different tool pin geometries, namely simple cylinder (SC), threaded cylinder with triflat faces (THF), and simple square (SS). The metallurgical aspects of unprocessed and processed weld regions were analyzed and correlated with the ultimate tensile strength, impact toughness, and microhardness properties. Results revealed that the post-FSP with a THF pin transformed the coarse dendritic structures (AGS of 34.55 µm) of the TIG weld into equiaxed fine structures (AGS of 3.51 µm) and increased the UTS, impact toughness, and microhardness by 71.51%, 95.40%, and 72.46%, respectively. The joint processed with the THF pin resulted in the highest ultimate tensile strength of 279 MPa, impact toughness of 15.02 J, and microhardness of 116.13 HV in the nugget region compared to the other two pin geometries. The highest joint properties of THF pin were attributed to the formation of fine grain structures in the nugget region, high effective strain and heat generation, improved material flow, and the decimation of intermetallic precipitates with their uniform dispersion in the nugget region. The tensile fractured surface of the TIG weldment had noticeable macro voids and coarse dimples with some rough cleavage facet in the fusion region, resulting in a brittle mode of failure. However, the tensile fractured surface of TIG + FSP weldments showed ductile failure due to the presence of fine and deep dimples with tear ridges without any void. [ABSTRACT FROM AUTHOR]

The synthesis of a strontium hexaferrite magnet is studied using in situ synchrotron powder X‐ray diffraction (PXRD) with a 16‐ms time resolution. The precursor material is cold compacted shape‐controlled goethite and strontium carbonate. The time evolution of the phases is modeled with sequential Rietveld refinements revealing that strontium hexaferrite forms within seconds at ≈1173 K. Texture analysis is performed on selected PXRD frames throughout the experiment, and the preferred orientation introduced by cold‐pressing goethite prevails through the iron oxide phase transitions (goethite → hematite → strontium hexaferrite). Electron backscatter diffraction (EBSD) data on the final pellet confirms the preferred orientation observed with PXRD. The resulting magnet has respectable magnetic properties, considering the simplicity of the preparation method, with an energy product (BHmax) of 18.6(8) kJ m−3. [ABSTRACT FROM AUTHOR]

During the hot pressing of pure titanium and different carbon steels in a temperature range of ϑ = 950–1050 ° C , a compound layer up to dL≈10 μ m thick is formed at the titanium–steel interface. With a higher carbon content of the used steel, the layer thickness increases. The carbon concentration within the layer is in the range of stoichiometry for TiC. Apart from TiC, no other phases can be detected by X-ray diffraction (XRD) measurements inside the formed layer. The calculation of the activation energy for the TiC layer formation is Q = 126.5–136.7 kJ mol−1 and is independent of the carbon content of the steel. The resulting microstructure has a grain size gradient, wherein the mechanical properties, such as hardness and Young's modulus, are almost constant. Statistical analysis using Response Surface Methodology (RSM) indicates that the carbon content of the steel has the most significant influence on layer thickness, followed by annealing temperature and annealing time. By selecting the appropriate carbon steel and the subsequent removal of the steel, it is possible to produce targeted TiC layers on titanium substrates, which holds enormous potential for this material in wear-intensive applications. [ABSTRACT FROM AUTHOR]

Copyright of Rare Metals is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The current trend in research on the physical properties of high-entropy alloys has been progressively increasing as there are many unknown possibilities for developing high-entropy alloys for advanced applications. This study investigated the effect of microstructures of rolled high-entropy alloy from the viewpoint of crystal orientation and dislocation density distribution to reproduce mechanical anisotropy using crystal plasticity finite element simulation. The crystal orientation and the geometrically necessary dislocation density of the rolled material were quantitatively estimated from experimental data of electron backscatter diffraction. Microstructural observation showed that particular textures were preferably oriented like in typical FCC metals. Even though the simulation results where only the preferred crystal orientation was considered did not show the expected mechanical anisotropy as in the experiment, the computational model with the dislocation density distribution and the preferred orientation showed the same tendency as the experiment. [ABSTRACT FROM AUTHOR]

Electron backscatter diffraction， five parameter analysis， overlap-pole-figure analysis and near coincident site analysis were used to investigate the interface character distributions of WC/WC grain boundaries and WC/Co phase boundaries in WC/Co cemented carbides under different heat treatment states. The results show that the WC/WC Σ2 grain boundaries with a fraction of 4.5% are generated in the oil-quenched sample after high temperature sintering. The fraction of Σ2 boundaries with interface matching features of ｛101¯0｝/｛101¯0｝ is 2.6%.The cobalt in this sample is basically face-centered-cubic structure， and the interface with the interface inter-connection features of ｛101¯0｝WC/｛001｝Co，｛101¯0｝WC/｛110｝Co and ｛112¯0｝WC/｛110｝Co is the main part of the WC/Co phase boundary. After tempering at 800 ℃， the samples with atmosphere protection and slow cooling in the furnace have the proportion and characteristics of WC/WC Σ2 grain boundaries， which are very close to those of oil-quenched samples.The cobalt in this sample is primarily hexagonal structure， and the interface with the interface inter-connection features of ｛101¯0｝WC/｛101¯0｝Co and ｛112¯0｝WC/｛112¯0｝Co is the main part of the WC/Co phase boundary.

In this study, we explored the deformation mechanisms of Mg single crystals using a combination of scanning electron microscopy and electron backscattered diffraction in conjunction with a dedicated four-point bending tester. We prepared two single-crystal samples, oriented along the 〈11‾20〉 and 〈101‾0〉 directions, to assess the mechanisms of deformation when the initial basal slip was suppressed. In the 〈11‾20〉 sample, the primary {101‾2} twin (T1) was confirmed along the 〈11‾20〉 direction of the sample on the compression side with an increase in bending stress. In the 〈101‾0〉 sample, T1 and the secondary twin (T2) were confirmed to be along the 〈11‾20〉 direction, with an orientation of ±60° with respect to the bending stress direction, and their direction matched with (0001) in T1 and T2. This result implies that crystallographically, the basal slip occurs readily. In addition, the 〈101‾0〉 sample showed the double twin in T1 on the compression side and the tertiary twin along the 〈101‾0〉 direction on the tension side. These results demonstrated that the maximum bending stress and displacement changed significantly under the bend loading because the deformation mechanisms were different for these single crystals. Therefore, the correlation between bending behavior and twin orientation was determined, which would be helpful for optimizing the bending properties of Mg-based materials.

Reducing the weight of the negative current collector is an effective strategy for lightweighting vehicle batteries. Herein, thin copper foil with high tensile strength was prepared through electrodeposition in Br−-based aqueous solution. The synergistic effect of additive Br−, polyethylene glycol (PEG), Bis-(sodium sulfopropyl)-disulfide (SPS) on the microstructure and tensile strength of the copper foils have been systematically explored. It was found that the addition of Br− modifies the microstructure of copper via grain refinement, thereby enhancing the mechanical properties of copper foil. The obtained copper foil reaches an enhanced tensile strength of 469.8 N/mm2 and an elongation of 2.2%. The results of electrochemical measurements confirm that Br− enhances electrochemical polarization of PEG and attenuates the acceleration of SPS. The improved mechanical properties of copper foils are attributed to the closer proximity and stronger adsorption energy between Br− and Cu atoms, which results in a synergy of grain refinement and nanotwinned grains associated with increased dislocation density as well as dislocations entangled around nanotwin GBs.

This research explores the effects of incorporating Graphene Nano Sheets (GNS) on the microstructural characteristics and mechanical behavior of Sn–Ag solder alloys. The research was driven by the need for environmentally friendly, lead-free solder alloys with enhanced mechanical and thermal properties. The methodology involved incorporating graphene into the Sn–Ag alloy through stir casting, followed by a series of surface preparation techniques. The composite samples were then examined using EBSD to analyze crystallographic orientations and SEM/EDS for surface morphology and elemental composition. XRD provided insights into phase transformations and structural changes. Key findings reveal that the addition of GNS significantly refines the grain structure of the Sn–Ag alloy, leading to a bimodal grain size distribution. This refinement is attributed to the role of GNS as a nucleation site during solidification. Moreover, the study demonstrates a pronounced alteration in the texture of the material, with an increase in low-angle grain boundaries post-GNS addition. This texture change is indicative of enhanced mechanical properties. The results also show a shift in the orientation distribution function (ODF), suggesting a stronger crystallographic orientation due to GNS. These findings suggest that GNS incorporation could lead to improved mechanical and thermal properties in Sn–Ag solder, making them suitable for high-performance electronic applications. The study concludes that GNS not only serves as an effective reinforcement in Sn–Ag solder alloys but also significantly alters their microstructural and textural characteristics, contributing to the alloy's potential application in environmentally conscious electronic manufacturing.

Cathodoluminescence and electron backscatter diffraction have been applied to exactly the same grain boundaries (GBs) in a Cu(In,Ga)S2 solar absorber in order to investigate the influence of microstructure on the radiative recombination behaviour at the GBs. Two different types of GB with different microstructure were analysed in detail: random high angle grain boundaries (RHAGBs) and Σ3 GBs. We found that the radiative recombination at all RHAGBs was inhibited to some extent, whereas at Σ3 GBs three different observations were made: unchanged, hindered, or promoted radiative recombination. These distinct behaviours may be linked to atomic-scale grain boundary structural differences. The majority of GBs also exhibited a small spectral shift of about ±10 meV relative to the local grain interior (GI) and a few of them showed spectral shifts of up to ±40 meV. Red and blue shifts were observed with roughly equal frequency. [ABSTRACT FROM AUTHOR]

To measure textures of hot rolled martensitic and bainitic steels, electron backscatter diffraction (EBSD) is applied to large areas, each covering about a thousand of prior grains. A scanning step is selected to keep reasonable time of the data acquisition still providing in any grain a significant number of analyzed points. Contributions to the transformation texture appearing from deformation and recrystallization components of the parent texture are estimated with the Bain relationship. To assess the parent austenite state, their proportion is then expressed by a scalar parameter. The results are verified by independent metallographic data. Avoiding the reconstruction of prior grains, this statistical approach will facilitate evaluation of complex austenite structures with comparable fractions of dissimilar material states. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Materials Engineering / Cailiao Gongcheng is the property of Journal of Materials Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study was aimed at examining the effect of the number of grains (representing the total measurement area) on the statistical variation of the area average of the kernel average orientation (KAM), denoted as KAMA, ave, as determined through electron backscatter diffraction (EBSD). Moreover, the number of triple junctions required to obtain statistically valid results was investigated. The results indicated that at least 80-100 grains should be evaluated to reduce the statistical dispersion in plastic-strain evaluation using KAMA, ave. The average triple junction KAM (KAMTJ, ave) values near the random boundary tend to be higher than those near coincident site lattice (CSL) boundaries. There was a correlation between plastic strain and average triple-junction KAM (KAMTJ, ave). This study highlights that KAMTJ is useful parameters for evaluating plastic strain around the triple junctions. [ABSTRACT FROM AUTHOR]

To achieve the desired microstructural properties, the ongoing development and innovation in new structural steels require novel thermal processing. This study aims to improve the mechanical properties of a commercial spring carbon–silicon steel by tailoring its microstructure through a process involving quenching and partitioning (Q&P) followed by bainitic transformation. A two‐stage Q&P process is proposed to generate a nanoscale dispersion of stable retained austenite and carbides within the tempered martensite and bainite microstructure. The resulting tensile properties demonstrate a yield strength of 1280 MPa, an ultimate tensile strength of 1875 MPa, and a total elongation of 8.03%. These values surpass those of conventional spring 9254 steel, highlighting the effectiveness of the thermal treatment design. Microstructure analysis reveals the presence of tempered martensite, bainite sheaves, nanoscale carbides, and aggregates of retained austenite. Moreover, the resulting body‐centered cubic matrix exhibits minimal lattice tetragonality of ≈1.0051, coupled with stable retained austenite featuring a carbon concentration of ≈3.42 ± 0.5 wt%, resulting in outstanding strength–ductility properties. These findings indicate that the proposed two‐stage Q&P process, followed by bainitic transformation, significantly enhances the mechanical properties of carbon–silicon steels, making it a promising candidate for high‐performance spring applications. [ABSTRACT FROM AUTHOR]

The crystal structure and transformation path from austenite to 10M martensite in Ni–Mn–Ga single crystal are examined employing high‐energy synchrotron radiation, scanning, and transmission electron microscopy. Using temperature gradient, an austenite/twinned martensite interface is stabilized revealing the crystal structure and microstructure of both phases and the transformation sequence across the interface. Depending on the distance from the interface, three distinct types of martensite crystal lattice, namely simple tetragonal and two monoclinic modulated ones, that is, 10M′ and 10M are confirmed. In situ measurements show that lattice mismatch formed at the habit plane is compensated by the formation of micro‐twinned and branched martensite along with an elastic change in lattice parameters. It is shown that the characteristics for periodic shuffling twin boundaries, such as modulation twins or inverted stacking faults, are installed in later stages of transformation. In other words, large microstructure elements that most efficiently accommodate the strain are installed first, and then smaller elements are operable. Overall, the experimental results show that the crystal lattice does not adapt modulated phase at the habit plane and cannot be built up from simple non‐modulated tetragonal blocks but rather a specific sequence of phase transformations using shear/shuffling deformation takes place. [ABSTRACT FROM AUTHOR]

Accurate age determination of impact cratering events remains difficult and controversial. Less than a quarter of all documented impact craters are regarded as accurately and precisely age dated. Zircon (U-Th)/He (ZHe) dating of impactites has received recent attention as a novel technique to date impact structures. Complicated and localized post-impact hydrothermal systems could also affect the reliability of ZHe impact ages. We quantitatively define the effects of shock-induced microstructures on He diffusion kinetics in zircon with different shock microstructures characterized by Secondary Electron Microscopy (SEM) and electron backscatter diffraction (EBSD). We investigated samples from the Chicxulub and Ries impact craters, to compare diffusion kinetics from structures of different sizes, ages, and hydrothermal activity. Step-heating fractional-release experiments were used to quantify He diffusion kinetics of variably shocked zircon and examine the relationship of the experimentally derived diffusion domain sizes to the EBSD-defined subgrains. The diffusion data show a consistent activation energy independent of shock level, while shock microstructures, such as planar deformation bands (PDBs) and granular textures systemically and dramatically lower the He retentivity due to the microstructural reduction of the effective diffusion domain size. Shocked zircon were dated by ZHe and the less deformed grains yield ages within error of the accepted impact ages as determined by other methods (40Ar/39Ar and U-Pb), whereas the grains with PDBs or granular textures commonly exhibited younger ages. Thus, the characterization of impact-induced zircon microstructures is critical for determining accurate impact ages because shocked grains are less suitable for reliable impact dating, but potentially powerful for exploring temperature–time history of hydrothermal activity. [ABSTRACT FROM AUTHOR]

• Displacement and maximum bending stress are higher in 〈10 1 ‾ 0〉 than in 〈 11 ‾ 20〉. • In the compression side of 〈10 1 ‾ 0〉, basal slip activates after primary and secondary twins (T1 and T2) deformation. • In the tension side of 〈10 1 ‾ 0〉, tertiary {10 1 ‾ 2} twin is parallel to the length axis on tension side. In this study, we explored the deformation mechanisms of Mg single crystals using a combination of scanning electron microscopy and electron backscattered diffraction in conjunction with a dedicated four-point bending tester. We prepared two single-crystal samples, oriented along the 〈 11 ‾ 20〉 and 〈10 1 ‾ 0〉 directions, to assess the mechanisms of deformation when the initial basal slip was suppressed. In the 〈 11 ‾ 20〉 sample, the primary {10 1 ‾ 2} twin (T1) was confirmed along the 〈 11 ‾ 20〉 direction of the sample on the compression side with an increase in bending stress. In the 〈10 1 ‾ 0〉 sample, T1 and the secondary twin (T2) were confirmed to be along the 〈 11 ‾ 20〉 direction, with an orientation of ±60° with respect to the bending stress direction, and their direction matched with (0001) in T1 and T2. This result implies that crystallographically, the basal slip occurs readily. In addition, the 〈10 1 ‾ 0〉 sample showed the double twin in T1 on the compression side and the tertiary twin along the 〈10 1 ‾ 0〉 direction on the tension side. These results demonstrated that the maximum bending stress and displacement changed significantly under the bend loading because the deformation mechanisms were different for these single crystals. Therefore, the correlation between bending behavior and twin orientation was determined, which would be helpful for optimizing the bending properties of Mg-based materials. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract The synthesis of a strontium hexaferrite magnet is studied using in situ synchrotron powder X‐ray diffraction (PXRD) with a 16‐ms time resolution. The precursor material is cold compacted shape‐controlled goethite and strontium carbonate. The time evolution of the phases is modeled with sequential Rietveld refinements revealing that strontium hexaferrite forms within seconds at ≈1173 K. Texture analysis is performed on selected PXRD frames throughout the experiment, and the preferred orientation introduced by cold‐pressing goethite prevails through the iron oxide phase transitions (goethite → hematite → strontium hexaferrite). Electron backscatter diffraction (EBSD) data on the final pellet confirms the preferred orientation observed with PXRD. The resulting magnet has respectable magnetic properties, considering the simplicity of the preparation method, with an energy product (BHmax) of 18.6(8) kJ m−3.

Previous research has consistently found that introducing metastable retained austenite (RA) as a second phase retards the failure of steel under fatigue. However, the reasons for this benefit are not understood. Accordingly, the properties of RA most advantageous to resist fatigue are not known. Within this context, this paper examines the interaction between second-phase RA and short fatigue crack growth in a steel processed via quenching and partitioning, using quasi in situ electron backscatter diffraction experiments. Results show that most RA transforms into martensite under the plastic strain surrounding the crack. They also reveal various mechanisms whereby RA transformation delays short fatigue crack propagation; transformation-induced crack closure (TICC), crack deflection and branching, and roughness-induced crack closure (RICC). Crack deflection and branching are driven by a tendency of cracks to propagate towards transformed RA, which is against the previous assumptions in the literature. Furthermore, the impact of crack deflection/branching on retardation is more powerful than that of TICC acting alone. Microstructures including second-phase RA should avoid RA-lean areas and promote elongated RA grains, with relatively large size, and major axis normal to the preferential crack growth direction. Untransformed RA within the plastic zone (i.e. overstabilized) does not contribute to crack retardation.

Additive manufacturing techniques, such as laser powder bed fusion (PBF-LB), are well known for their exceptional freedom in part design. However, these techniques are also characterized by the development of large thermal gradients during production and thus residual stress (RS) formation in produced parts. In this context, neutron diffraction enables the non-destructive characterization of the bulk RS distribution. By control of the thermal gradients in the powder-bed plane by scan strategy variation we study the impact of in-process scan strategy variations on the microstructure and the three-dimensional distribution of RS. Microstructural analysis by means of electron backscatter diffraction reveals sharp microstructure transitions at the interfaces ranging from 100-200 µm. The components of the RS tensor are determined by means of neutron diffraction and the principal stress directions and magnitudes are determined by eigenvalue decomposition. We find that the distribution of RS in the powder-bed plane corresponds to the underlying scan strategy. When the alternating scan vectors align with the x- and y sample coordinate axes, the principal stress directions co-align. In the present geometry, nearly transverse isotropic stress states develop when the scan vectors are either aligned 45° between x and y or continuously rotated by 67° between each layer.

Nitrogen solid solution can effectively enhance the strength of steels, but its effect on grain boundary engineering and the corrosion mechanism of steels is still unclear and systematic investigation is needed. In this study, 316LN steel specimens with five nitrogen concentrations were melted and subjected to compression and annealing. The grain boundary character distribution was investigated by electron backscatter diffraction. The corrosion behavior was investigated by the electrochemical polarization curves, electrical impedance spectroscopy, and X-ray photoelectron spectroscopy. The results showed that nitrogen promotes the formation of low-Σ boundaries when the pre-strain is not above 10%. The polarization resistance increases with increasing nitrogen content. The quantitative relationship between the nitrogen content and the pitting potential was obtained. Nitrogen favors the formation of oxides, hydroxides, and NH3/NH4+ on the passivated surface. The effect of planar slip on grain boundary engineering and the influence of NH4+ on the corrosion resistance are discussed.

Scanning electron microscopy‐based high‐resolution digital image correlation (HRDIC) is now an established technique, providing full‐field strain and displacement measurement at the microscale. Techniques for generating speckle patterns for sub‐micron strain mapping can often be either substrate dependent or rely on applying aggressive conditions which may alter the microstructure of interest or damage the substrate in highly sensitive materials. We detail a modification of a methodology successfully applied in the literature to allow its use with metallic materials that are particularly sensitive to the corrosive media, such as copper‐base alloys. Nanometre‐thick silver films, applied with physical vapour deposition, are remodelled using NaBr in non‐aqueous isopropanol, replacing the aqueous solution of NaCl in the original method, forming a uniform dispersion of silver islands highly suitable for digital image correlation (DIC) measurement. The entire procedure is performed at ambient temperature. We find that the DIC pattern is suitably electron transparent to allow electron backscatter diffraction (EBSD) measurements without pattern removal, producing diffraction patterns of sufficient quality for cross‐correlation based high‐angular resolution EBSD. This property facilitates simultaneous EBSD and DIC mapping experiments, providing deeper insights into the kinematics of plastic deformation in crystalline materials. Sub‐100 nm islands are achieved through control of the sputter coating parameters, resulting in DIC cross‐correlation subwindows of 140 nm with a 50% overlap. This resolution is sufficient to capture the fine detail of strain localisation phenomena during plastic deformation, demonstrated here with a case study in CuCrZr, a precipitation‐hardened heat sink material for application in nuclear fusion components. Here, we extract full‐field displacement data with DIC and corresponding orientation information using EBSD without the need for pattern removal. [ABSTRACT FROM AUTHOR]

Sub-micro dislocation cellular structures formed during rapid solidification break the strength–ductility trade-off in laser powder bed fusion (LPBF)-processed 316L stainless steel through high-density dislocations and segregated elements or precipitates at the cellular boundaries. The high-density dislocation entangled at the cellular boundary accommodates solidification strains among the cellular structures and cooling stresses through elastoplastic deformation. Columnar grains with cellular structures typically form along the direction of thermal flux. However, the ultra-low misorientations between the adjacent cellular structures and their interactions with the cellular boundary formation remain unclear. In this study, we revealed the ultra-low misorientations between the cellular structures in LPBF-processed 316L stainless steel using conventional electron backscatter diffraction (EBSD), transmission Kikuchi diffraction (TKD), and transmission electron microscopy (TEM). The conventional EBSD and TKD analysis results could provide misorientation angles smaller than 2°, while the resolution mainly depends on the specimen quality and scanning step size, and so on. A TEM technique with higher spatial resolution provides accurate information between adjacent dislocation cells with misorientation angles smaller than 1°. This study presents evidence that the TEM method is the better and more precise analytical method for the misorientation measurement of the cellular structures and provides insights into measuring the small misorientation angles between adjacent dislocation cells and nanograins in nanostructured metals and alloys with ultrafine-grained microstructures. [ABSTRACT FROM AUTHOR]

Pure shear tests of textured magnesium AZ31B sheet samples were carried out using a 5 kN Kammrath & Weiss in situ tension-compression stage in a scanning electron microscope in combination with real-time electron backscatter diffraction lattice orientation mapping. The sample design was optimized to produce a pure shear stress in the central gauge zone. Distributions of the deformation twins were correlated with finite element simulations using a linear-elastic constitutive law considering large deformations to show that twins form in areas where the principal compressive stress σ 3 * is a maximum and that they form normal to the trajectories of that minor principal stress. Mappings of the same area at different load values revealed the formation and growth of individual twins and their relationship to the internal elastic strain of individual grains as indicated by the internal grain disorientation. All twins observed were of the extension type, with an 86.3° disorientation with respect to the parent grains. A more detailed study was conducted using transmission electron microscopy to correlate with the EBSD observations and to further elucidate the twin structures within samples. [ABSTRACT FROM AUTHOR]

The Geometrically Necessary Dislocation (GND) density was estimated from Electron Backscatter Diffraction (EBSD) data for an AZ31/Mg-0.6Gd (wt.%) hybrid material fabricated by high-pressure torsion (HPT) at room temperature through an equivalent strain range of ϵeq = 0.3–144 using Kernel Average Misorientation (KAM) and the Nye tensor approaches. The results show that generally the GND densities are significant at the beginning of the deformation (ϵeq = 0.3) and decrease in both alloys when ϵeq increases. The Mg-0.6Gd alloy exhibits a lower GND density due to rapid dynamic recrystallization. These results were compared to the GND densities measured in AZ31 and Mg-0.6Gd mono-materials processed separately by HPT under the same experimental conditions. In these mono-materials the GND densities increase with increasing equivalent strain up to 7 and then decrease with further straining. The Mg-0.6Gd and AZ31 regions of the hybrid material exhibit higher GND densities than the mono-materials particularly at low strain where the disc thickness and the bonding of the AZ31/Mg-0.6Gd interfaces cause more deformation heterogeneity in the hybrid material. It is shown that the GND density evolution as a function of ϵeq has the same tendency for the KAM and the Nye approaches but the average values are significantly higher with the Nye approach. An analysis suggests that the Nye approach overestimates the GND density of the Mg-based alloys. [ABSTRACT FROM AUTHOR]

The wire arc additive manufacturing process employing metal inert gas welding is a superior method for constructing large-scale components at a subsidized cost. This process has been experimented on Incoloy 825 for various industrial applications in large-scale industries like marine, chemical processing, and pressure vessel industries. This work mainly focuses on studying the microstructural properties and mechanical behavior of the wire arc additively manufactured (WAAMed) Incoloy 825 material. Microstructural analysis, x-ray diffraction analysis, Energy-Dispersive x-ray Spectroscopy, Electron Backscatter Diffraction analysis, hardness behavior, and tensile behavior of WAAMed Incoloy 825 were investigated. Titanium-rich secondary particles were observed using Energy-Dispersive x-ray Spectroscopy. In addition, location and orientation-based tensile strength and elongation behavior have been studied. Compared with wrought Incoloy 825, the WAAMed Incoloy 825 specimen inclined at 45° achieved nearly 86% ultimate tensile strength and 90% elongation. Fractography studies revealed that the WAAMed Incoloy 825 specimens exhibited a ductile fracture with large plastic deformation and brittle fracture in some areas. [ABSTRACT FROM AUTHOR]

The aluminium based matrix composites have excellent mechanical properties to use in automobile, aerospace, aviation, and military industries. The aluminium based matrix composite possesses desired characteristics like specific strength, excellent rigidity and wear resistance. The stir casting technique was used to fabricate the nanocomposite of AA6063 alloy reinforced with 5 weight % nano aluminium oxide particulate. To improve the microhardness of as cast and aluminium based nanocomposites, multiaxial forging was performed up to three passes for grain refinement. Wire electrical discharge machining was used to machine both as cast and "AA6063/Al2O3" (zero and three multi axial forging pass). The machining characteristics of samples were statistically examined using the Taguchi technique. The material removal rate in three multiaxial forging pass nanocomposite sample increased as peak current increases. However, increasing the pulse off time resulted in the lowest material removal rate. The surface roughness was found to be higher in the nanocomposite sample in comparison to as cast. The machining on nanocomposite multiaxial forged sample has a greater impact as compared to as cast. After machining, scanning electron microscopy was used to examine the surface morphology. The presence of different elements in the castings was validated using energy dispersive X‐ray spectroscopy. [ABSTRACT FROM AUTHOR]

High carbon stainless steel 347H (SS347H) and Inconel 625 (IN625) are high-strength alloys, commonly used in high-temperature applications. These metals are commonly used in the fabrication of concentrated solar power energy storage tanks and pipelines. Construction of such tanks involves dissimilar welding as the primary manufacturing process. The critical factor to consider when joining two different materials is the development of microstructure, as it directly impacts the mechanical characteristics of the joints. According to the available literature, an increase in the heat input (HI) promotes alloying element segregation and susceptibility to weld cracking. Traditional arc welding processes, such as metal inert gas (MIG) welding, produce a higher HI. Therefore, there is a need to develop welding techniques that result in reduced HI. In the present study, a pulse-current MIG (PC-MIG) welding method was employed, utilizing current pulsing to minimize HI during the welding process. The welding was followed by metallographic and mechanical characterization. The microstructural examination found variations in microstructure at different regions. Electron backscatter diffraction analysis shows the crystallographic orientation at different regions. Analysis shows that both SS347H and IN625 have a face-centred cubic austenite structure. The inverse pole figure discloses strong texture formation. The average tensile strength of dissimilar weldments was found to be 479 MPa, while the average hardness value of the fusion zone was measured to be 235 HV. The research indicates that the PC-MIG technique is suitable for joining dissimilar materials with reduced HI, effectively eliminating the risk of cracking and enhancing the efficiency of the joint. [ABSTRACT FROM AUTHOR]

In the present study, the effect of aging conditions on the microstructure, mechanical properties, and shape memory behavior of a solution-treated Fe-17Mn-5Si-5Cr-4Ni-0.2Ti-0.1C shape memory alloy was investigated. In addition, a revised mechanism for the precipitation-induced improvement of the shape memory effect (SME) is proposed. The effect of increasing the aging temperature from 500 to 900 °C was evaluated with a fixed time of 0.5 h, finding that the SME was initially improved upon increasing the temperature up to 600 °C, whereas further increasing the aging temperature exerted a detrimental effect on the SME. This was attributed to the change in the fractions of the ε and γ phases. The same increasing and decreasing trends were observed when the aging time was increased while maintaining the temperature constant at 600 °C. In this case, no change in the fractions of the ε and γ phases was detected. Instead, a change in the size and distribution of TiC precipitates might be the main reason for changes in properties. The presence of finer and densely distributed precipitates in the sample aged for 3.0 h could lead to a higher integrated pulling force, back stress, stacking faults, or ε phase cutting through the precipitates, resulting in a more effective back-transformation from ε to γ, compared with the sample aged for 6.0 h, which exhibits larger and sparsely distributed precipitates. Continuously decreased and increased 0.2% proof and tensile stress indicated an easier martensitic transformation in the early stage of deformation and precipitation hardening. However, according to the different trend in the SME and 0.2% proof stress, not only an easier martensitic transformation from γ to ε but also an integrated pulling force, which can be altered by tuning the size and distribution of precipitates, should be considered to achieve high SME induced by carbide precipitation. [ABSTRACT FROM AUTHOR]

In this article, slow strain rate tensile (SSRT) test were carried out on laser peened hydrogen charged Ti6Al4V samples to analyze the effect of hydrogen on mechanical properties. Ti6Al4V alloy subjected to two different laser peening conditions is investigated using transmission electron microscope (TEM) and electron backscatter diffraction (EBSD) to understand the grain refinement and texture orientation. The microstructural images of TEM indicated the existence of newly formed grain boundaries, slip bands and hexagonal networks. The bright-field image of line like structure demonstrate the formation of 10 1 ¯ 1 twin which indicates the occurence of β/α′ martensitic transformation. Accumulation of dislocations and shear bands formed during laser peening played an important role preserving the mechanical properties even after samples subjected to hydrogen charging. Test sample, laser peened with ablation coating and hydrogen charged shown a loss of elongation δ L with 14.11% compared to test sample laser peened without ablation coating and hydrogen charged shown 19.16%, indicating that sample peened with no ablation have significance in reduction of elongation loss. Both the samples shows the reduced tensile strain at break (standard) % compared to as-received test sample. Test sample laser peened without ablation coating shown high strain rate deformation and intense grain refinement at top surface due to the adiabatic temperature. The experimental results demonstrate that the laser peening has considerable desired effect in protecting mechanical properties of Ti6Al4V alloy even after subjected to hydrogen charging. [ABSTRACT FROM AUTHOR]

Seismic anisotropy constitutes a useful tool for imaging the structure along the plate interface in subduction zones, but the seismic properties of mafic blueschists, a common rock type in subduction zones, remain poorly constrained. We applied the technique of electron backscatter diffraction (EBSD) based petrofabric analysis to calculate the seismic anisotropies of 14 naturally deformed mafic blueschists at dry, ambient conditions. The ductilely deformed blueschists were collected from terranes with inferred peak P‐T conditions applicable to subducting slabs at or near the plate interface in active subduction zones. Epidote blueschists display the greatest P wave anisotropy range (AVp ∼7%–20%), while lawsonite blueschist AVp ranges from ∼2% to 10%. S wave anisotropies generate shear wave splitting delay times up to ∼0.1 s over a thickness of 5 km. AVp magnitude increases with glaucophane abundance (from areal EBSD measurements), decreases with increasing epidote or lawsonite abundance, and is enhanced by glaucophane crystallographic preferred orientation (CPO) strength. Two‐phase rock recipe models provide further evidence of the primary role of glaucophane, epidote, and lawsonite in generating blueschist seismic anisotropy. The symmetry of P wave velocity patterns reflects the deformation‐induced CPO type in glaucophane—an effect previously observed for hornblende on amphibolite P wave anisotropy. The distinctive seismic properties that distinguish blueschist from other subduction zone rock types and the strong correlation between anisotropy magnitude/symmetry and glaucophane CPO suggest that seismic anisotropy may be a useful tool in mapping the extent and deformation of blueschists along the interface, and the blueschist‐eclogite transition in active subduction zones. Plain Language Summary: The directional dependence of seismic wave speeds in the subsurface, or seismic anisotropy, can allow us to map the Earth's structure in subduction zones. To improve the interpretation of seismic data collected in active subduction zones, we characterized the range of seismic anisotropy created by blueschists (a common subduction zone rock‐type) that were returned to the surface after being deformed in ancient subduction margins. We calculate the anisotropy of each blueschist rock from mineral orientations collected in the lab combined with the elastic properties of these minerals. Trends in seismic anisotropy were compared to the changes in composition and preferred orientations of minerals (produced by deformation). We found that blueschists can generate a broad range of seismic anisotropy, and that this anisotropy is enhanced by increasing amounts of the mineral glaucophane. The seismic anisotropy is further increased when the glaucophane minerals are more uniformly oriented, as is typical in rocks that have experienced higher levels of deformation. The seismic anisotropy and seismic wave speeds of blueschists are distinctive from those of other common subduction zone rocks. Therefore, these results suggest blueschist seismic anisotropy can be used to improve our ability to map structure and deformation occurring in active subduction zones. Key Points: Calculated blueschist Vp anisotropy up to ∼20% with a plateau at ∼10%, with lineation‐parallel fast axis and foliation‐normal slow axisThe anisotropy magnitude increases with glaucophane modal abundance/crystallographic preferred orientation (CPO) strength and is diluted by epidote/lawsonite abundanceThe glaucophane CPO type correlates with the Vp pattern and increasing AVp magnitude in mafic blueschists [ABSTRACT FROM AUTHOR]

Electron backscatter diffraction (EBSD) methods are used to investigate the presence of microstructures in pyrite from the giant breccia-hosted Olympic Dam iron–oxide copper gold (IOCG) deposit, South Australia. Results include the first evidence for ductile deformation in pyrite from a brecciated deposit. Two stages of ductile behavior are observed, although extensive replacement and recrystallization driven by coupled dissolution–reprecipitation reaction have prevented widespread preservation of the earlier event. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) element maps of pyrite confirm that many pyrite grains display compositional zoning with respect to As, Co, and Ni, but that the zoning is often irregular, patchy, or otherwise disrupted and are readily correlated with observed microstructures. The formation of ductile microstructures in pyrite requires temperatures above ~260 °C, which could potentially be related to heat from radioactive decay and fault displacements during tectonothermal events. Coupling EBSD methods with LA-ICP-MS element mapping allows a comprehensive characterization of pyrite textures and microstructures that are otherwise invisible to conventional reflected light or BSE imaging. Beyond providing new insights into ore genesis and superimposed events, the two techniques enable a detailed understanding of the grain-scale distribution of minor elements. Such information is pivotal for efforts intended to develop new ways to recover value components (precious and critical metals), as well as remove deleterious components of the ore using low-energy, low-waste ore processing methods. [ABSTRACT FROM AUTHOR]

The prime objective of this work is to find the best combination of parameters in laser welding of stainless-steel 304 H plates. CO2 laser welding was used to join 5 mm thick stainless-steel 304 H plates. Laser power, welding speed, and focal position were used as input parameters, and experiments were conducted on the basis of the Taguchi L27 matrix. The quality of the weld was analysed by measuring depth of penetration, bead width and hardness. The best parameter combination was found using artificial neural network and genetic algorithm. The Levenberg–Marquardt algorithm predicted output responses more accurately. A confirmatory test was carried out for the optimized parameters identified by the genetic algorithm. The percentage error between the experimental and predicted genetic algorithm values was below 6%. In comparison to the base metal, the optimized weld hardness was increased by 8%. The electron backscatter diffraction analysis of the optimized weld revealed the presence of a higher percentage of high-angle grain boundary than low-angle grain boundary. [ABSTRACT FROM AUTHOR]

The study and modelling of material degradation processes, such as the initiation and growth of creep cavities in high-temperature applications, require a correlative and comprehensive knowledge of the microstructure. However, individual microscopy is limited to a small region and specific microstructural information of the specimen. This work demonstrates a novel correlative microscopy approach for characterising creep cavitation and establishing correlations with local microstructural parameters in a statistical manner. This approach combines datasets from stitched higher-resolution backscattered electron (BSE) images, XeF2 Focused Ion Beam (FIB) images, and backscattered electron diffraction (EBSD) maps with advanced image correlation techniques. Deep-learning image segmentation techniques and statistical analysis are applied to find relations between creep cavitation and local microstructural environment. This approach is demonstrated in a cyclic creep-tested 316H stainless steel specimen with extensive creep cavities. The results show that in this material, strain localization, grain boundary misorientation, and substantial precipitation dominate the nucleation of cavities, whereas other microstructural properties such as grain size and Schmid factor play smaller roles. This study presents the use of the correlative microscopy approach to provide new insights into creep cavitation behaviour and its implications for establishing creep cavitation damage models.

Commercially pure titanium (CP Ti) with a hexagonal close-packed structure exhibits large anisotropy and asymmetry at room temperature. While several reasons have been put forth to explain such unique behavior, the deformation mechanism responsible for the observed anisotropy and asymmetric yielding and hardening is not clearly understood. In this study, to understand the deformation mechanism of CP Ti and investigate the origin of such unusual mechanical behavior, a micromechanical analysis was conducted using electron backscatter diffraction (EBSD) and crystal plasticity finite element analyses. Representative volume elements of titanium sheets were generated using statistical data related to the microstructure, as analyzed using EBSD. Crystal plasticity model parameters corresponding to different deformation modes, including prismatic, basal, pyramidal slip, {101‾2} tensile twinning, and {112‾2} compressive twinning, were calibrated using the macroscopic behavior in various loading conditions. Finally, the roles of different deformation modes in dictating the anisotropic and asymmetric behavior of CP Ti are discussed.

During the hot pressing of pure titanium and different carbon steels in a temperature range of ϑ = 950–1050 °C, a compound layer up to dL≈10 μm thick is formed at the titanium–steel interface. With a higher carbon content of the used steel, the layer thickness increases. The carbon concentration within the layer is in the range of stoichiometry for TiC. Apart from TiC, no other phases can be detected by X-ray diffraction (XRD) measurements inside the formed layer. The calculation of the activation energy for the TiC layer formation is Q = 126.5–136.7 kJ mol−1 and is independent of the carbon content of the steel. The resulting microstructure has a grain size gradient, wherein the mechanical properties, such as hardness and Young‘s modulus, are almost constant. Statistical analysis using Response Surface Methodology (RSM) indicates that the carbon content of the steel has the most significant influence on layer thickness, followed by annealing temperature and annealing time. By selecting the appropriate carbon steel and the subsequent removal of the steel, it is possible to produce targeted TiC layers on titanium substrates, which holds enormous potential for this material in wear-intensive applications.

Thallium bromide (TlBr) semiconductor detectors are promising candidates for highdetection-efficiency, high-energy-resolution, and room-temperature gamma-ray spectrometers. In this study, we conducted neutron Bragg dip and electron backscatter diffraction (EBSD) imaging of TlBr crystals to measure the crystal orientation distribution. We confirmed that crystal grains were continuous over a certain distance along the solidification direction for samples fabricated with the current growth procedure. Finally, we compared the crystal orientation maps obtained with the two techniques. The two types of maps showed similar patterns. We concluded that EBSD, which can observe only surfaces, can be utilized to assess the uniformity of the bulky TlBr crystal, especially when observing the crystal surface perpendicular to the solidification direction. [ABSTRACT FROM AUTHOR]

High‐strength low‐alloy (HSLA) steels are widely used to their excellent mechanical properties. Despite this, the precipitation process occurring during annealing after cold rolling has not been extensively studied. Herein, the precipitation of niobium carbide (NbC) is examined during both hot‐rolling and annealing processes. Field emission transmission electron microscopy and inductively coupled plasma optical emission spectroscopy are employed for the analyses, with a particular focus on using the residual electrochemical extraction method for quantification. The NbC precipitates formed during hot rolling and annealing are individually assessed. The findings indicate that new NbC precipitates form during annealing process after cold rolling, and these precipitates are smaller than those formed during hot rolling. This study offers valuable insights into the precipitation process of NbC in cold‐rolled HSLA steel and has implications for the development of improved steel processing techniques. [ABSTRACT FROM AUTHOR]

Electron backscatter diffraction (EBSD) is an excellent tool for characterizing the crystallographic orientation aspects of the microstructure of polycrystalline material. In some additively manufactured materials, the material may undergo a phase transformation during the forming process. Although EBSD can only characterize the final microstructure, neighbor information from orientation mapping allows the microstructure before the phase transformation to be reconstructed, provided that the parent–child orientation relationship is known. An investigation of the effectiveness of the reconstruction algorithms for capturing the grain size as well as orientation gradients is undertaken with a focus on additively manufactured Ti-alloy. The EBSD results, coupled with reconstruction algorithms, reveal information on the prior grain size as well as the plastic flow of the material. [ABSTRACT FROM AUTHOR]

Strain-controlled uniaxial compression tests on textured magnesium AZ31B sheet samples were carried out using a 5 kN Kammrath & Weiss tension–compression in situ stage using a scanning electron microscope in combination with real-time electron backscatter diffraction lattice orientation mapping. The distribution of deformation twins in the samples was studied and correlated with the results of finite element simulation of the elastic strain to show that bands of twinned grains formed in areas where the principal compressive stress (σ3) was a maximum, and they formed normal to the trajectory of the principal direction of σ3. This was correlated with maps of lattice disorientation within the grains, which showed the inclination for twins to grow in alignment with local and larger-scale distributions of elastic strain. Mappings of the same area at different values of strain were made to examine the formation and growth of individual twins within the macroscopic bands of twinned grains. All the twins observed were consistent with the extension-type twin, with 86.3° disorientation with respect to the parent grain. Mappings of the grain internal disorientation were related to the elastic strain, and it was found that twin formation and growth followed the contours of the highest elastic strain within and across grains. The maximum angular disorientation found within the grains was approximately 10°, suggesting that this might correspond to a threshold of elastic strain required to initiate twinning. [ABSTRACT FROM AUTHOR]