Crystallographic orientation of ilmenite inclusions in amphibole – an electron backscatter diffraction study

2020 ◽  
Vol 235 (4-5) ◽  
pp. 105-116
Author(s):  
Chang Xu ◽  
Shanrong Zhao ◽  
Jiaohua Zhou ◽  
Xu He ◽  
Haijun Xu
Keyword(s):  
Crystallographic Orientation ◽  
Electron Backscatter Diffraction ◽  
Reduction Reaction ◽  
Formation Temperature ◽  
Orientation Relationships ◽  
Ultra High Pressure ◽  
Electron Backscatter ◽  
Metamorphic Terrane ◽  
Backscatter Diffraction ◽  
Group 1

AbstractOrientated ilmenite inclusions have been discovered in amphibole of hornblendite from the Zhujiapu area, Dabie ultra-high-pressure (UHP) metamorphic terrane, China. In order to characterize the crystallographic orientation relationships between ilmenite inclusions and amphibole host and reconstruct the mechanism of their formation, we present an electron backscatter diffraction (EBSD) analysis combined with energy dispersive spectroscopy (EDS) analysis and electron microprobe analysis (EPMA) for ilmenite inclusions and amphibole host. The inclusions can be subdivided into four groups: (1) 60.2% of ilmenites have the crystallographic orientation {0001}Ilm // {100}Amp, (101̅0)Ilm // {010}Amp, [112̅0]Ilm // <001> Amp and [112̅0]Ilm // <012 > Amp. (2) 16.5% of ilmenites have <0001> Ilm // <001> Amp, (101̅0)Ilm // {010}Amp, (112̅0)Ilm // {100}Amp and [3̅031]Ilm // <012> Amp. (3) 13.8% of ilmenites have <0001> Ilm // <012> Amp, (112̅0)Ilm // {100}Amp and [3̅031]Ilm // <001> Amp. (4) 9.5% of ilmenites have <0001> Ilm // [1̅12]Amp, (101̅0)Ilm // {201}Amp, [112̅0]Ilm // [1̅12]Amp and ${[11\overline {21} ]_{Ilm}}$// <010> Amp. By comparing the lattice relationship between ilmenite inclusions and amphibole hosts, it is shown that the frequency of the ilmenite inclusions in different groups is related to the lattice coherency and oxygen packing. Group-1 of the ilmenite inclusions was most likely be formed via a solid-state exsolution process by cooling of the hornblendite after the intrusion was emplaced. The other three groups of ilmenite inclusions were probably formed via reduction reaction in an open system. The formation temperature of the ilmenite inclusions is estimated by using the TiO2 solubility geothermeter in amphibole. The minimum formation temperature of the ilmenite inclusions is about 1025 °C, and the maximum formation temperature of the ilmenite inclusions is about 1126 °C.

scholarly journals Crystallographic and shape orientations of magnetite micro-inclusions in plagioclase

2020 ◽  
Vol 175 (10) ◽  
Author(s):  
Olga Ageeva ◽  
Ge Bian ◽  
Gerlinde Habler ◽  
Alexey Pertsev ◽  
Rainer Abart
Keyword(s):  
Crystallographic Orientation ◽  
Crystal Orientation ◽  
Lattice Spacing ◽  
Electron Backscatter Diffraction ◽  
Metamorphic Rocks ◽  
Orientation Relationships ◽  
Electron Backscatter ◽  
Backscatter Diffraction ◽  
Universal Stage ◽  
Scanning Electron

Abstract Plagioclase hosted, oriented magnetite micro-inclusions are a frequently observed phenomenon in magmatic and metamorphic rocks. Understanding the orientation relationships between these inclusions and the plagioclase host is highly relevant for interpreting paleomagnetic measurements. The systematics of the shape and crystallographic orientation relationships between needle- and lath-shaped magnetite micro-inclusions and their plagioclase host from oceanic gabbro were investigated using optical microscopy including universal stage measurements, scanning electron microscopy, and crystal orientation analysis by electron backscatter diffraction. The magnetite inclusions show preferred shape orientations following six well-defined directions and with specific crystallographic orientation relationships to the plagioclase host. These relationships are rationalized based on angular and dimensional similarities between the crystal structures of magnetite and plagioclase, which favor the parallel alignment of oxygen layers with similar lattice spacing in both phases. The parallel alignment of oxygen layers in plagioclase and magnetite can be traced back to the oriented nucleation of magnetite, which occurs by the accommodation of FeO6 octahedra in six-membered rings of SiO4 and AlO4 tetrahedra of the plagioclase structure. The orientation systematics of the magnetite micro-inclusions is related to four orientation variants for placing the FeO6 octahedra into the plagioclase structure.

scholarly journals Using electron backscatter diffraction to measure full crystallographic orientation in Antarctic land-fast sea ice

2018 ◽  
Vol 64 (247) ◽  
pp. 771-780 ◽  
Author(s):  
PAT WONGPAN ◽  
DAVID J. PRIOR ◽  
PATRICIA J. LANGHORNE ◽  
KATHERINE LILLY ◽  
INGA J. SMITH
Keyword(s):  
Sea Ice ◽  
Crystallographic Orientation ◽  
Electron Backscatter Diffraction ◽  
Preferred Orientation ◽  
Angle Distribution ◽  
Crystal Preferred Orientation ◽  
Electron Backscatter ◽  
Backscatter Diffraction ◽  
First Time ◽  
Platelet Ice

ABSTRACTWe have mapped the full crystallographic orientation of sea ice using electron backscatter diffraction (EBSD). This is the first time EBSD has been used to study sea ice. Platelet ice is a feature of sea ice near ice shelves. Ice crystals accumulate as an unconsolidated sub-ice platelet layer beneath the columnar ice (CI), where they are subsumed by the advancing sea–ice interface to form incorporated platelet ice (PI). As is well known, in CI the crystal preferred orientation comprises dominantly horizontal c-axes, while PI has c-axes varying between horizontal and vertical. For the first time, this study shows the a-axes of CI and PI are not random. Misorientation analysis has been used to illuminate the possible drivers of these alignments. In CI the misorientation angle distribution from random pairs and neighbour pairs of grains are indistinguishable, indicating the distributions are a consequence of crystal preferred orientation. Geometric selection during growth will develop the a-axis alignment in CI if ice growth in water is fastest parallel to the a-axis, as has previously been hypothesised. In contrast, in PI random-pair and neighbour-pair misorientation distributions are significantly different, suggesting mechanical rotation of crystals at grain boundaries as the most likely explanation.

Twin and topotactic growth of β-eucryptite dendrites and their lattice coincidence analysed by the reticular theory

2013 ◽  
Vol 46 (1) ◽  
pp. 216-223
Author(s):  
Shan-Rong Zhao ◽  
Hai-Jun Xu ◽  
Rong Liu ◽  
Qin-Yan Wang ◽  
Xian-Yu Liu
Keyword(s):  
Solid Solution ◽  
Crystallographic Orientation ◽  
Electron Backscatter Diffraction ◽  
Electron Backscatter ◽  
Ebsd Technique ◽  
Backscatter Diffraction ◽  
Orientation Determination

Snowflake-shaped dendrites of β-eucryptite–β-quartz solid solution were artificially crystallized in a matt glaze, and the crystallographic orientation of the dendrites was analysed by the electron backscatter diffraction (EBSD) technique. The six branches of a snowflake-shaped dendrite in the plane (0001) are along 〈110〉. From the orientation determination, a twin relationship and a topotactic relationship between dendrites were found. The twin axes are [011], [0{\overline 1}1] and [210], and the twin planes perpendicular to the twin axes are ({\overline 1}2{\overline 1}2) and (1{\overline 2}12). From the reticular theory of twinning, it was calculated that the twin indexn= 2 and the obliquity ω = 3.2877°. The studied dendrite is a twin by reticular pseudomerohedry with low twin index and obliquity. In the topotactic growth, no twin elements have been found, but the three main crystallographic directions 〈001〉, 〈210〉 and 〈110〉 of the two dendritic crystals overlap each other. The degree of lattice coincidence between the two crystals in this topotactic growth is also discussed.

Examination of the Orientation Relationships between the Main Phases of Duplex Stainless Steel by EBSD

2007 ◽  
Vol 537-538 ◽  
pp. 297-302
Author(s):  
Tibor Berecz ◽  
Péter János Szabó
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Stainless Steels ◽  
Electron Backscatter Diffraction ◽  
Duplex Stainless Steels ◽  
Alloying Elements ◽  
Orientation Relationships ◽  
Σ Phase ◽  
Electron Backscatter ◽  
Backscatter Diffraction

Duplex stainless steels are a famous group of the stainless steels. Duplex stainless steels consist of mainly austenitic and ferritic phases, which is resulted by high content of different alloying elements and low content of carbon. These alloying elements can effect a number of precipitations at high temperatures. The most important phase of these precipitation is the σ-phase, what cause rigidity and reduced resistance aganist the corrosion. Several orientation relationships have been determined between the austenitic, ferritic and σ-phase in duplex stainless steels. In this paper we tried to verify them by EBSD (electron backscatter diffraction).

Inherited Fabric in an Omphacite Symplectite: Reconstruction of Plastic Deformation under Ultra-High Pressure Conditions

2013 ◽  
Vol 19 (4) ◽  
pp. 942-949 ◽  
Author(s):  
Florian Heidelbach ◽  
Michael P. Terry
Keyword(s):  
Orientation Relationship ◽  
Electron Backscatter Diffraction ◽  
Pure Shear ◽  
Additional Component ◽  
Western Gneiss Region ◽  
Crystallographic Preferred Orientation ◽  
Ultra High Pressure ◽  
Shear Component ◽  
Electron Backscatter ◽  
Backscatter Diffraction

AbstractWe investigated an eclogitic gneiss from the Western Gneiss Region in Norway, which underwent subduction as part of Baltica lithosphere beneath Laurentia during the Scandian orogeny. Petrologic data indicate that the eclogite was deformed plastically at about 4 GPa and 800°C producing a strong macroscopic foliation and lineation. Whereas garnet remained largely stable during the retrograde uplift, omphacite was transformed statically into a symplectite consisting of lamellar diopside and plagioclase with more equant grains of hornblende and orthopyroxene. Measurements of the crystallographic preferred orientation with electron backscatter diffraction show that diopside and hornblende, as well as orthopyroxene, have a systematic orientation relationship with the macroscopic fabric, as well as the (presumed) orientation of the host omphacite. The orientation relationship between the chain silicates is very sharp with the crystallographic forms {100}, {010}, and ⟨001⟩ being parallel. Their bulk texture shows a maximum of ⟨001⟩ parallel to the lineation and girdles of {010} and {110} perpendicular to the lineation with maxima subparallel to the foliation corresponding to an L-type texture of the original omphacite and indicating constrictional strain with an additional component of pure shear/simple shear component.

scholarly journals A New Electron Backscatter Diffraction-Based Method to Study the Role of Crystallographic Orientation in Ductile Damage Initiation

Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 113
Author(s):  
Behnam Shakerifard ◽  
Jesus Galan Lopez ◽  
Leo A. I. Kestens
Keyword(s):  
Crystallographic Orientation ◽  
Electron Backscatter Diffraction ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Second Phase ◽  
Post Mortem ◽  
Bainitic Steel ◽  
Damage Initiation ◽  
Electron Backscatter ◽  
Backscatter Diffraction

The third generation of advanced high strength steels shows promising properties for automotive applications. The macroscopic mechanical response of this generation can be further improved by a better understanding of failure mechanisms on the microstructural level and micro-mechanical behavior under various loading conditions. In the current study, the microstructure of a multiphase low silicon bainitic steel is characterized with a scanning electron microscope (SEM) equipped with an electron backscatter diffraction detector. A uniaxial tensile test is carried out on the bainitic steel with martensite and carbides as second phase constituents. An extensive image processing on SEM micrographs is conducted in order to quantify the void evolution during plastic deformation. Later, a new post-mortem electron backscatter diffraction-based method is introduced to address the correlation between crystallographic orientation and damage initiation. In this multiphase steel, particular crystallographic orientation components were observed to be highly susceptible to micro-void formation. It is shown that stress concentration around voids is rather relaxed by void growth than local plasticity. Therefore, this post-mortem method can be used as a validation tool together with a crystal plasticity-based hardening model in order to predict the susceptible crystallographic orientations to damage nucleation.

Analysis of Multiphase Materials Using Electron Backscatter Diffraction

1997 ◽  
Vol 3 (S2) ◽  
pp. 561-562
Author(s):  
S.I. Wright ◽  
D.P. Field
Keyword(s):  
Crystallographic Orientation ◽  
Electron Backscatter Diffraction ◽  
Computer Control ◽  
Orientation Imaging Microscopy ◽  
Spatial Arrangement ◽  
Polycrystalline Materials ◽  
Orientation Data ◽  
Topological Features ◽  
Electron Backscatter ◽  
Backscatter Diffraction

Image analysis techniques coupled with crystallography computer codes have been used to index electron backscatter diffraction patterns (EBSPs). The ability to automatically obtain the crystallographic orientation from EBSPs coupled with computer control of the electron beam (or stage) in a scanning electron microscope (SEM) provides a much more complete description of the spatial distribution of crystallographic orientation in polycrystalline materials than has been previously attainable using conventional metallography techniques. Orientation data obtained using this technique can be used to form images reflecting the spatial arrangement of crystallographic orientation in a microstructure. Such images enable the topological features of a microstructure to be linked with the orientation characteristics. The formation of these images, as well as the data collection technique, is sometimes termed Orientation Imaging Microscopy (OIM). The utility of this technique for exploring the property/structure relationship in polycrystalline material has been demonstrated by numerous researchers. However, as yet, this technique has almost exclusively been applied to single phase materials.

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