Showing papers on "Electron backscatter diffraction published in 2014"
20 Oct 2014-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, the effect of the microstructure on the tensile properties of additive manufacturing (AM) of Ti alloys has been investigated. And the authors found that the mechanical anisotropy of the parts was discussed in relation to the crystallographic texture, phase composition and the predominant fracture mechanisms.
Abstract: Recent research on the additive manufacturing (AM) of Ti alloys has shown that the mechanical properties of the parts are affected by the characteristic microstructure that originates from the AM process. To understand the effect of the microstructure on the tensile properties, selective laser melted (SLM) Ti–6Al–4V samples built in three different orientations were tensile tested. The investigated samples were near fully dense, in two distinct conditions, as-built and stress relieved. It was found that the build orientation affects the tensile properties, and in particular the ductility of the samples. The mechanical anisotropy of the parts was discussed in relation to the crystallographic texture, phase composition and the predominant fracture mechanisms. Fractography and electron backscatter diffraction (EBSD) results indicate that the predominant fracture mechanism is intergranular fracture present along the grain boundaries and thus provide and explain the typical fracture surface features observed in fracture AM Ti–6Al–4V.
671 citations
TL;DR: In this paper, the authors used optical and SEM micrographs to show the observed grain structure in the SLM fabricated and Hot Isostatically Pressed (HIPped) material and found that the repeating pattern shown in the grain structure has been linked to the overlapping of the "island" pattern used as standard in the Concept Laser M2 powder-bed facility.
556 citations
TL;DR: In this article, a nonequiatomic FeMnNiCoCr alloy is introduced and characterized at multiple scales employing various characterization techniques (e.g., atom probe tomography, electron channeling contrast imaging, electron backscatter diffraction, etc.) to elucidate the role of configurational entropy and intrinsic tensile ductility of high-entropy alloys.
525 citations
TL;DR: In this paper, the authors present a simple, yet instructive and demonstrative treatment of the theory of ECC of lattice defects based on Bloch wave theory using a two-beam approach.
422 citations
TL;DR: In this article, a high-resolution scanning electron microscopy-based damage quantification technique has been employed to identify strain regimes where damage nucleation and damage growth take place, both with and without hydrogen precharging.
327 citations
TL;DR: In this paper, an experimental-numerical methodology is introduced to strengthen the integrated understanding of microstructure and mechanical properties of multiphase alloys, enabling joint analyses of deformation-induced evolution of the micro-structure, and the strain and stress distribution therein, down to sub-micron resolution.
280 citations
TL;DR: In this article, the authors investigated the formation of annealing twins in the FCC-structured equiatomic CoCrFeMnNi high-entropy alloy by arc melting and drop casting.
239 citations
TL;DR: In this article, the formation process of the bainitic microstructure as well as martensite and retained austenite was revealed by conducting dilatometry, X-ray diffraction, scanning electron microscopy, electron backscatter diffraction and transmission electron microscope (TEM).
239 citations
TL;DR: In this paper, a model of the TRIP-maraging steel microstructure was designed with support from diffusion simulations (using DICTRA software) to investigate size effects on cRN transformation independent of other factors that can influence austenite stability.
216 citations
TL;DR: In this article, the transformation texture was studied in a Ti-6Al-4V alloy for two microstructures produced through different phase transformation mechanisms (i.e. diffusional vs. displacive).
176 citations
TL;DR: In this paper, hydrogen embrittlement of a precipitation-hardened Fe-26Mn-11Al-1.2C (wt.%) austenitic steel was examined by tensile testing under hydrogen charging and thermal desorption analysis.
TL;DR: In this paper, transmission Kikuchi diffraction (TKD) is combined with energy dispersive X-ray spectroscopy (EDS) to provide complementary chemical information, while a standard forescatter detector system can be used to generate dark field and oriented dark field images.
TL;DR: In this paper, the grain-scale elastoplastic deformation behavior of coarse-grained body centered cubic (BCC) tantalum was simulated using a crystal plasticity finite element method (CP-FEM) and compared to experimental measurements of intragranular strain and rotation fields.
TL;DR: In this paper, hydrogen embrittlement of austenitic stainless steels has been examined with respect to deformation microstructures and lattice defects created during plastic deformation and the onset of fracture is likely due to plastic instability.
TL;DR: In this paper, the strengthening contributions in medium-carbon tempered martensite are revealed by using transmission electron microscopy and synchrotron radiation X-ray diffraction, the different microstructural features have been captured; these include precipitation, grain boundary, solid solution and dislocation forest strengthening.
TL;DR: This paper presents the first successful application of a combined focused ion beam (FIB)/t-EBSD preparation of site-specific APT specimens using the example of grain boundary segregation in technically pure molybdenum.
TL;DR: In this paper, electron backscatter diffraction (EBSD) has been used to characterize the block-and-packet structure of lath martensite in low-carbon 9Ni steel.
TL;DR: In this article, a detailed characterization of nanostructured thin zirconium oxide films formed during aqueous corrosion of a nuclear-grade ZrConium alloy (Zircaloy-4) has been carried out by means of two novel, ultra-high-spatial-resolution grain mapping techniques, namely automated crystal orientation mapping in the transmission electron microscope (TEM) and transmission electron backscatter diffraction (t-EBSD).
TL;DR: In this article, high-resolution scanning electron microscopy (SEM) observations were used to determine the morphology of each grain with quantitative measurement of the grain's orientation via electron backscatter diffraction in SEM.
TL;DR: In this paper, the calibration of the two-dimensional detector and full analysis of the sample is performed inside the Rietveld least-squares fitting instead of a preliminary graphical calibration.
Abstract: Synchrotron X-ray diffraction images are increasingly used to characterize not only structural and microstructural features of polycrystalline materials, but also crystal preferred orientation distributions. Diffraction data can be analyzed quantitatively and efficiently with the Rietveld method and here the detailed procedure is reported from the experiment to the calibration of the two-dimensional detector and full analysis of the sample. In particular, we emphasize the advantage of doing the calibration inside the Rietveld least-squares fitting instead of a preliminary graphical calibration. Then the procedure is described to quantify crystal preferred orientations with the Rietveld method implemented in software Materials Analysis Using Diffraction. The process is illustrated for a US nickel coin, a 75 at.% copper 25 at.% nickel alloy with face-centered cubic structure and a strong cube texture. © 2014 International Centre for Diffraction Data.
TL;DR: In this paper, a micro-laser aided additive manufacturing (micro-LAAM) was successfully implemented on nickel-base superalloy IN100, which is known to have poor weldability due to weld liquation cracking in the heat-affected zone (HAZ) and strain age cracking.
TL;DR: In this paper, the analysis procedure for diffraction images collected with high energy X-rays for a complex, multiphase shale, and for those collected in situ in diamond anvil cells at high pressure and anisotropic stress are described.
Abstract: Synchrotron X-ray diffraction images are increasingly used to characterize crystallographic preferred orientation distributions (texture) of fine-grained polyphase materials. Diffraction images can be analyzed quantitatively with the Rietveld method as implemented in the software package Materials Analysis Using Diffraction. Here we describe the analysis procedure for diffraction images collected with high energy X-rays for a complex, multiphase shale, and for those collected in situ in diamond anvil cells at high pressure and anisotropic stress.
TL;DR: In this paper, electron backscatter diffraction (EBSD) is applied to measure the plastic strain present in RR1000 nickel-based superalloy microstructure following thermo-mechanical fatigue tests.
TL;DR: In this paper, a 304L austenitic stainless steel was subjected to different heat inputs by shielded metal arc welding process using a standard 308L electrode and microstructural developments were characterized by using optical microscopy and electron backscattered diffraction, while the residual stresses were measured by X-ray diffraction using the sin 2 ψ method.
TL;DR: In this article, two co-zone twins are activated and interact with each other, resulting in two types of tilt boundaries that have habit planes (0001) and (101¯0) and prevent twin-across-twin transmission but facilitate the propagation of a basal slip band.
Abstract: Using in situ optical microscopy, electron backscatter diffraction analysis, and atomistic simulations, we studied co-zone {1¯012} twin interaction in magnesium single crystal under compression–tension along the [101¯0] direction. Two co-zone twins are activated and interact with each other, resulting in two types of tilt boundaries that have habit planes (0001) and (101¯0) and prevent twin-across-twin transmission but facilitate the propagation of a basal slip band. Upon strain reversal, the unfavorable dissociation of dislocations in the formed tilt boundaries hinder de-twinning.
TL;DR: In this paper, the effect of overlapping between consecutive passes of FSP was examined on the microstructure, microtexture, and mechanical properties of Al 6063, and the results showed that SHTA led to grain growth with an average grain size of 35μm.
TL;DR: In this paper, the evolution of dislocation clusters in high performance multicrystalline silicon was studied by means of photoluminescence imaging, defect etching and Electron Backscatter Diffraction.
TL;DR: In this article, electron backscatter diffraction analysis was employed to compute the closest orientation relationship and the distribution of intervariant boundary character in a lath martensitic microstructure.
TL;DR: In this paper, surface integrity and wear mechanisms associated with mechanical micro-drilling of nickel-base superalloy (Inconel 718) under dry and wet cutting conditions were investigated.
Abstract: The study focuses on the surface integrity and wear mechanisms associated with mechanical micro-drilling of nickel-base superalloy (Inconel 718) under dry and wet cutting conditions. Mechanical and metallurgical characterization was undertaken using scanning electron microscopy (SEM), backscatter electron microscopy (BSE), electron backscatter diffraction microscopy (EBSD), transmission electron microscopy (TEM), focused ion beam (FIB) microscopy, nanoindentation, energy dispersive spectroscopy (EDS) and elemental analysis techniques. The surface integrity results revealed large scale near surface deformations with high dislocation density along with nanocrystalline grain structures both under wet cutting conditions, with evidence of recrystallisation and lower dislocation density for dry cutting. Cutting conditions play a significant role in determining the depth of the affected layer, the frequency of misorientations, the microstructures and the stored energy found there. The cutting temperature and use of coolant play a key role in the formation of the altered surfaces. Abrasion, diffusion and micro-chipping were found to be the main wear mechanisms for wet cutting compared to abrasion, high adhesion, macro-chipping and catastrophic failure for dry cutting. Adhesion of work-piece material to the tool associated with abrasion and diffusion processes is the main contributor to wear phenomena. The results are important in guiding the choice of cutting conditions for acceptable surface integrity.
TL;DR: XRDUA as mentioned in this paper is a software tool to convert large sequences of powder diffraction patterns into a limited set of crystalline phase maps in an integrated fashion, which can facilitate the execution of the complete sequence of data reduction and interpretation steps.
Abstract: Imaging of crystalline phase distributions in heterogeneous materials, either plane projected or in virtual cross sections of the object under investigation, can be achieved by scanning X-ray powder diffraction employing X-ray micro beams and X-ray-sensitive area detectors. Software exists to convert the two-dimensional powder diffraction patterns that are recorded by these detectors to one-dimensional diffractograms, which may be analysed by the broad variety of powder diffraction software developed by the crystallography community. However, employing these tools for the construction of crystalline phase distribution maps proves to be very difficult, especially when employing micro-focused X-ray beams, as most diffraction software tools have mainly been developed having structure solution in mind and are not suitable for phase imaging purposes. XRDUA has been developed to facilitate the execution of the complete sequence of data reduction and interpretation steps required to convert large sequences of powder diffraction patterns into a limited set of crystalline phase maps in an integrated fashion.