Orientation relationship of eutectoid FeAl and FeAl2

Fe–Al alloys in the aluminium range of 55–65 at.% exhibit a lamellar microstructure of B2-ordered FeAl and triclinic FeAl2, which is caused by a eutectoid decomposition of the high-temperature Fe5Al8 phase, the so-called ∊ phase. The orientation relationship of FeAl and FeAl2 has previously been studied by Bastin et al. [J. Cryst. Growth (1978), 43, 745] and Hirata et al. [Philos. Mag. Lett. (2008), 88, 491]. Since both results are based on different crystallographic data regarding FeAl2, the data are re-evaluated with respect to a recent re-determination of the FeAl2 phase provided by Chumak et al. [Acta Cryst. (2010), C66, i87]. It is found that both orientation relationships match subsequent to a rotation operation of 180° about a 〈112〉 crystallographic axis of FeAl or by applying the inversion symmetry of the FeAl2 crystal structure as suggested by the Chumak data set. Experimental evidence for the validity of the previously determined orientation relationships was found in as-cast fully lamellar material (random texture) as well as directionally solidified material (∼〈110〉FeAl || solidification direction) by means of orientation imaging microscopy and global texture measurements. In addition, a preferential interface between FeAl and FeAl2 was identified by means of trace analyses using cross sectioning with a focused ion beam. On the basis of these habit planes the orientation relationship between the two phases can be described by ({\overline 1}01)FeAl || (114)_{{\rm FeAl}_2}^{\rm Chumak} and [111]FeAl || [1\overline{1}0]_{{\rm Fe Al}_2}^{\rm Chumak}. There is no evidence for twinning within FeAl lamellae or alternating orientations of FeAl lamellae. Based on the determined orientation and interface data, an atomistic model of the structure relationship of Fe5Al8, FeAl and FeAl2 in the vicinity of the eutectoid decomposition is derived. This model is analysed with respect to the strain which has to be accommodated at the interface of FeAl and FeAl2.

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On the multiple orientation relationship of the Mg/γ-Mg17Al12precipitation system

Journal of Applied Crystallography ◽

10.1107/s002188981200091x ◽

2012 ◽

Vol 45 (2) ◽

pp. 224-233 ◽

Cited By ~ 7

Author(s):

Hongwei Liu ◽

Jiangwen Liu ◽

Liuzhang Ouyang ◽

Chengping Luo

Keyword(s):

Orientation Relationship ◽

Simple Structure ◽

Close Packing ◽

Orientation Relationships ◽

Complicated Structure ◽

Starting Point ◽

The Matrix ◽

Gross Energy ◽

Relationship Of ◽

Habit Planes

The six orientation relationships (ORs) found in the Mg/γ-Mg17Al12precipitation system were summarized and systematically interpreted based on the atomic structure of the precipitate γ-Mg12Al17and the invariant deformation element (IDE) model for diffusional phase transformations. It was found that the pseudo-twinning relationship between the six ORs is a reflection of the pseudo-twinning relationship between the close- or near-close-packing planes ({\overline 8}\hskip.75{\overline 7}\hskip.75{\overline 7}), ({\overline 4}11), (033), (411) and (8{\overline 7}\hskip.75{\overline 7}) in the precipitate γ-Mg12Al17. As a result, the Pitsch–Schrader OR is the starting point for the other five ORs. Multiple morphologies, growth directions and habit planes could be rationally interpreted by the IDE model. This implies that a multiple orientation relationship between the variants of precipitates is favourable in order to minimize the gross energy of precipitation systems in which the matrix has a simple structure while the precipitate has a complicated structure, such as Mg/γ-Mg12Al17, Mg/δ-Zn2Zr3and Mg/η-MgZn2couples.

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Epitaxial Gold in Au/Si Eutectic Reaction and Epitaxial Aluminum Spikes in Al-1%Si/Ti-W/Si System

MRS Proceedings ◽

10.1557/proc-116-471 ◽

1988 ◽

Vol 116 ◽

Cited By ~ 1

Author(s):

Peng-Heng Chang

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Epitaxial Growth ◽

Orientation Relationship ◽

Gold Film ◽

Eutectic Reaction ◽

Orientation Relationships ◽

Transmission Electron ◽

Relationship Of ◽

The Relationship

AbstractEpitaxial regrowth of gold film on Si as a result of Au/Si eutectic reaction and epitaxial aluminum spikes forming at IC contacts during sintering have been investigated by transmission electron microscopy (TEM). For gold film on Si, three types of epitaxy were observed: (1) the crystal structures of the two lattices are exactly the same, (2) the two structures have the orientation relationship of Au(111)//Si(111) and Au[132]//Si[231] and (3) 20° misorientation from the relationship in (2). Two orientation relationships were observed in the case of Al spike in Si: (1) Al[011]//Si[123] and Al(200)//Si(11), (2) Al[001]//Si[112] and 2° misorientation between Al(200) and Si(111). Possible mechanisms are proposed to explained the observed epitaxial growth.

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Automated reconstruction of parent austenite phase based on the optimum orientation relationship

Journal of Applied Crystallography ◽

10.1107/s1600576721001394 ◽

2021 ◽

Vol 54 (2) ◽

pp. 569-579

Author(s):

Edgar Gomes de Araujo ◽

Hadi Pirgazi ◽

Mehdi Sanjari ◽

Mohsen Mohammadi ◽

Leo A. I. Kestens

Keyword(s):

Orientation Relationship ◽

Phase Structure ◽

Electron Backscatter Diffraction ◽

Parent Phase ◽

Austenite Phase ◽

Angular Deviation ◽

Phase Reconstruction ◽

Orientation Relationships ◽

Automated Identification ◽

Data Set

Characterization of the austenite phase at high temperatures is important for understanding the microstructural evolution during steel processing. The austenite phase structure can be reconstructed from the room-temperature microstructure employing the crystallographic orientation relationship between the parent and product phases. The actual orientation relationships in steels are often calculated on the basis of well known relations (e.g. Kurdjumov–Sachs), which may differ from the experimentally observed orientation relationships. This work introduces a new approach to improve the current state of the art in prior phase reconstruction. The proposed approach consists of two new algorithms that are sequentially applied on an electron backscatter diffraction (EBSD) measured data set of the product phase microstructure: (i) an automated identification of the optimum orientation relationship using the observed misorientation distribution of the entire EBSD scan and (ii) reconstruction of the parent phase microstructure using a random walk clustering technique. The latter identifies groups of closely related grains according to their angular deviation from the proposed orientation relationship. The results were validated by near in situ experimental observations of phase transformation in an Fe–Ni alloy whereby the experimentally measured parent phase structure could be compared point by point with the reconstructed counterpart.

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A comparative study on methods for determining the hydraulic properties of a clay shale

Geophysical Journal International ◽

10.1093/gji/ggaa532 ◽

2020 ◽

Vol 224 (3) ◽

pp. 1523-1539

Author(s):

Lisa Winhausen ◽

Alexandra Amann-Hildenbrand ◽

Reinhard Fink ◽

Mohammadreza Jalali ◽

Kavan Khaledi ◽

...

Keyword(s):

Pore Pressure ◽

Effective Stress ◽

Ion Beam ◽

Applied Pressure ◽

Pressure Oscillation ◽

Stress Conditions ◽

Data Set ◽

Clay Shale ◽

Permeability Coefficients ◽

Effective Stresses

SUMMARY A comprehensive characterization of clay shale behavior requires quantifying both geomechanical and hydromechanical characteristics. This paper presents a comparative laboratory study of different methods to determine the water permeability of saturated Opalinus Clay: (i) pore pressure oscillation, (ii) pressure pulse decay and (iii) pore pressure equilibration. Based on a comprehensive data set obtained on one sample under well-defined temperature and isostatic effective stress conditions, we discuss the sensitivity of permeability and storativity on the experimental boundary conditions (oscillation frequency, pore pressure amplitudes and effective stress). The results show that permeability coefficients obtained by all three methods differ less than 15 per cent at a constant effective stress of 24 MPa (kmean = 6.6E-21 to 7.5E-21 m2). The pore pressure transmission technique tends towards lower permeability coefficients, whereas the pulse decay and pressure oscillation techniques result in slightly higher values. The discrepancies are considered minor and experimental times of the techniques are similar in the range of 1–2 d for this sample. We found that permeability coefficients determined by the pore pressure oscillation technique increase with higher frequencies, that is oscillation periods shorter than 2 hr. No dependence is found for the applied pressure amplitudes (5, 10 and 25 per cent of the mean pore pressure). By means of experimental handling and data density, the pore pressure oscillation technique appears to be the most efficient. Data can be recorded continuously over a user-defined period of time and yield information on both, permeability and storativity. Furthermore, effective stress conditions can be held constant during the test and pressure equilibration prior to testing is not necessary. Electron microscopic imaging of ion-beam polished surfaces before and after testing suggests that testing at effective stresses higher than in situ did not lead to pore significant collapse or other irreversible damage in the samples. The study also shows that unloading during the experiment did not result in a permeability increase, which is associated to the persistent closure of microcracks at effective stresses between 24 and 6 MPa.

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The Complete DNA Sequence of the Mitochondrial Genome of a “Living Fossil,” the Coelacanth (Latimeria chalumnae)

Genetics ◽

10.1093/genetics/146.3.995 ◽

1997 ◽

Vol 146 (3) ◽

pp. 995-1010 ◽

Cited By ~ 1

Author(s):

Rafael Zardoya ◽

Axel Meyer

Keyword(s):

Mitochondrial Genome ◽

Tandem Repeats ◽

Phylogenetic Analyses ◽

Large Data ◽

Molecular Data ◽

Phylogenetic Position ◽

Data Set ◽

Living Fossil ◽

Latimeria Chalumnae ◽

Relationship Of

The complete nucleotide sequence of the 16,407-bp mitochondrial genome of the coelacanth (Latimeria chalumnae) was determined. The coelacanth mitochondrial genome order is identical to the consensus vertebrate gene order which is also found in all ray-finned fishes, the lungfish, and most tetrapods. Base composition and codon usage also conform to typical vertebrate patterns. The entire mitochondrial genome was PCR-amplified with 24 sets of primers that are expected to amplify homologous regions in other related vertebrate species. Analyses of the control region of the coelacanth mitochondrial genome revealed the existence of four 22-bp tandem repeats close to its 3′ end. The phylogenetic analyses of a large data set combining genes coding for rRNAs, tRNA, and proteins (16,140 characters) confirmed the phylogenetic position of the coelacanth as a lobe-finned fish; it is more closely related to tetrapods than to ray-finned fishes. However, different phylogenetic methods applied to this largest available molecular data set were unable to resolve unambiguously the relationship of the coelacanth to the two other groups of extant lobe-finned fishes, the lungfishes and the tetrapods. Maximum parsimony favored a lungfish/coelacanth or a lungfish/tetrapod sistergroup relationship depending on which transversion:transition weighting is assumed. Neighbor-joining and maximum likelihood supported a lungfish/tetrapod sistergroup relationship.

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Morphology and orientation relationship of VC precipitates in HSLA steel

Journal of University of Science and Technology Beijing Mineral Metallurgy Material ◽

10.1016/s1005-8850(06)60085-6 ◽

2006 ◽

Vol 13 (5) ◽

pp. 420-423 ◽

Cited By ~ 2

Author(s):

Shijian Yan ◽

Xiaoping Liu ◽

Wenhuai Tian

Keyword(s):

Orientation Relationship ◽

Hsla Steel ◽

Relationship Of

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Molecular Systematics of Tribe Physarieae (Brassicaceae) Based on Nuclear ITS, LUMINIDEPENDENS, and Chloroplast ndhF

Systematic Botany ◽

10.1600/036364421x16312067913318 ◽

2021 ◽

Author(s):

Sara Fuentes-Soriano ◽

Elizabeth A. Kellogg

Keyword(s):

Sequence Data ◽

Plastid Dna ◽

Sister Relationship ◽

Data Set ◽

Woody Perennial ◽

History Of ◽

Nuclear Its ◽

Phylogenetic Framework ◽

Phylogenetic Hypotheses ◽

Relationship Of

Physarieae is a small tribe of herbaceous annual and woody perennial mustards that are mostly endemic to North America, with its members including a large amount of variation in floral, fruit, and chromosomal variation. Building on a previous study of Physarieae based on morphology and ndhF plastid DNA, we reconstructed the evolutionary history of the tribe using new sequence data from two nuclear markers, and compared the new topologies against previously published cpDNA-based phylogenetic hypotheses. The novel analyses included ca. 420 new sequences of ITS and LUMINIDEPENDENS (LD) markers for 39 and 47 species, respectively, with sampling accounting for all seven genera of Physarieae, including nomenclatural type species, and 11 outgroup taxa. Maximum parsimony, maximum likelihood, and Bayesian analyses showed that these additional markers were largely consistent with the previous ndhF data that supported the monophyly of Physarieae and resolved two major clades within the tribe, i.e., DDNLS (Dithyrea, Dimorphocarpa, Nerisyrenia, Lyrocarpa, and Synthlipsis)and PP (Paysonia and Physaria). New analyses also increased internal resolution for some closely related species and lineages within both clades. The monophyly of Dithyrea and the sister relationship of Paysonia to Physaria was consistent in all trees, with the sister relationship of Nerisyrenia to Lyrocarpa supported by ndhF and ITS, and the positions of Dimorphocarpa and Synthlipsis shifted within the DDNLS Clade depending on the employed data set. Finally, using the strong, new phylogenetic framework of combined cpDNA + nDNA data, we discussed standing hypotheses of trichome evolution in the tribe suggested by ndhF.

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TARGETED ADVERTISING IN THE BREAKFAST CEREAL INDUSTRY

Journal of Agricultural and Applied Economics ◽

10.1017/aae.2017.1 ◽

2017 ◽

Vol 49 (3) ◽

pp. 382-399 ◽

Cited By ~ 3

Author(s):

JOSHUA BERNING ◽

ADAM N. RABINOWITZ

Keyword(s):

Product Differentiation ◽

Food Product ◽

Television Advertising ◽

Breakfast Cereal ◽

Data Set ◽

Policy Makers ◽

Relationship Of ◽

Cereal Industry ◽

The Relationship ◽

Insight Into

AbstractWe examine the relationship of product characteristics of ready-to-eat breakfast cereal and targeted television advertising to specific consumer segments. We compile a unique data set that includes brand-packaging characteristics, including on-box games, nutrition information, and cobranding. We find that the relationship of television advertising and a cereal's brand-packaging characteristics varies by target audience. Our results provide insight into understanding how manufacturers strategically utilize branding, packaging, and television advertising. This can help industry and policy makers develop food product advertising policy. This analysis extends to other product markets where extensive product differentiation and promotion are present as well.

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Scanning transmission imaging in the helium ion microscope using a microchannel plate with a delay line detector

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.11.167 ◽

2020 ◽

Vol 11 ◽

pp. 1854-1864

Author(s):

Eduardo Serralta ◽

Nico Klingner ◽

Olivier De Castro ◽

Michael Mousley ◽

Santhana Eswara ◽

...

Keyword(s):

Delay Line ◽

Ion Beam ◽

Microchannel Plate ◽

Wide Energy Range ◽

High Angle ◽

Data Set ◽

Beam Position ◽

Angle Scattering ◽

Helium Ion ◽

Scanning Transmission

A detection system based on a microchannel plate with a delay line readout structure has been developed to perform scanning transmission ion microscopy (STIM) in the helium ion microscope (HIM). This system is an improvement over other existing approaches since it combines the information of the scanning beam position on the sample with the position (scattering angle) and time of the transmission events. Various imaging modes, such as bright field and dark field or the direct image of the transmitted signal, can be created by post-processing the collected STIM data. Furthermore, the detector has high spatial and temporal resolution, is sensitive to both ions and neutral particles over a wide energy range, and shows robustness against ion beam-induced damage. A special in-vacuum movable support gives the possibility of moving the detector vertically, placing the detector closer to the sample for the detection of high-angle scattering events, or moving it down to increase the angular resolution and distance for time-of-flight measurements. With this new system, we show composition-dependent contrast for amorphous materials and the contrast difference between small-angle and high-angle scattering signals. We also detect channeling-related contrast on polycrystalline silicon, thallium chloride nanocrystals, and single-crystalline silicon by comparing the signal transmitted at different directions for the same data set.

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