scholarly journals Authigenic rhabdophane from brown iron ore of the oxidation zone of the Babaryk massive sulfide occurrence (South Urals): scanning electron microscope (SEM) and electron backscattered diffraction (EBSD) study

2021 ◽  
Vol 33 (5) ◽  
pp. 605-620
Author(s):  
Elena V. Belogub ◽  
Vladimir V. Shilovskikh ◽  
Konstantin A. Novoselov ◽  
Ivan A. Blinov ◽  
Ksenia A. Filippova
Keyword(s):  
Rare Earth ◽  
Electron Microscope ◽  
Chemical Composition ◽  
Scanning Electron Microscope ◽  
Iron Ore ◽  
Massive Sulfide ◽  
South Urals ◽  
Electron Backscattered Diffraction ◽  
Fine Grained ◽  
Scanning Electron

Abstract. Rhabdophane (Ce0.34−0.43Nd0.13−0.14Ca0.06−0.29La0.08−0.11Y0.05−0.12Pr0.03−0.05Sm0.02−0.05Gd0.02−0.05Fe0−0.04Dy0.00-0.01)0.97-1.01((P0.69−0.96S0.04−0.31)1.00O4)⚫H2O is found in a Fe3+-oxyhydroxide nodule (brown iron ore) collected from the upper part of the oxidation profile of the Babaryk massive sulfide occurrence (South Urals, Russia) at a 1.6 m depth. The structural and microtextural features of rhabdophane are revealed by electron backscattered diffraction (EBSD); the chemical composition and distribution of the main components are determined on a scanning electron microscope (SEM) equipped with an energy-dispersive analyzer (EDA); the bulk contents of rare earth elements (REEs) and other elements in rock samples are analyzed using inductively coupled plasma mass spectrometry (ICP-MS). Rhabdophane forms spherulitic aggregates up to 35 µm in size with a fine-grained core and radial radiant rims composed of prismatic crystals. The chaotically oriented aggregates of its particles of various sizes including prismatic crystals and spherulitic intergrowths also fill fractures up to 200 µm long and 20–30 µm thick in goethite. The zonal radial radiant structure of the rhabdophane aggregates and their occurrence in fractures of goethite unambiguously indicate the authigenic origin of rhabdophane. The chemically heterogeneous rhabdophane grains always contain Y, Ca and S and rarely Fe and Sr and are Th- or U-free. Contrasting zonation of Ca, S and Y contents is characteristic of spherulites. The band contrast of the EBSD patterns shows a good crystallinity of prismatic crystals regardless of the chemical composition even for Ca–S-rich zones. On the other hand, the Ca- and S-rich fine-grained centers of the spherulites do not yield any distinguishable diffraction patterns. There is a strong negative correlation in pairs (Ca+Sr)–P and (REEs+Y)–S and a positive correlation in pairs (Ca+Sr)–S and (REEs+Y)–P, which indicates the isomorphism according to the scheme (REEs+Y)3+ + (PO4)3− ↔ (Ca+Sr)2+ + (SO4)2−. Thus, the chemical composition of rhabdophane does not completely correspond to the rhabdophane–tristramite/brockite series because of the absence of tetravalent U or Th. In contrast to similar samples from the deeper part of the oxidation zone, the brown iron ore with rhabdophane is enriched in light rare earth elements (LREEs) and P. The REEs were probably sourced from ore-bearing volcanomictic rocks, while P could also have been derived from the soil. The enrichment in REEs and P and the formation of rhabdophane are related to the alternation of dry and wet periods, the P input, and sorption–desorption of REEs from Fe3+ oxyhydroxides and/or clay minerals due to pH changes and variable composition of pore water.

Effect of the Neodymium Content on Mechanical Properties of the Electro-Brush Plated Nano-Al2O3/Ni Composite Coating

2012 ◽  
Vol 525-526 ◽  
pp. 277-280
Author(s):  
Guo Jin ◽  
Xiu Fang Cui ◽  
Er Bao Liu ◽  
Qing Fen Li
Keyword(s):  
Mechanical Properties ◽  
Rare Earth ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Composite Coating ◽  
Nanoindentation Test ◽  
X Ray Diffraction ◽  
X Ray ◽  
Small Cracks ◽  
Scanning Electron

The effect of the neodymium content on mechanical properties of the electro-brush plated nanoAl2O3/Ni composite coating was investigated in this paper. The microstructure and phase structure were studied with scanning electron microscope (SEM) and X-ray diffraction (XRD). The hardness and abrasion properties of several coatings with different neodymium content were studied by nanoindentation test and friction / wear experiment. Results show that the coatings are much finer and more compact when the neodymium was added, and the hardness and abrasion property of the coatings with neodymium were improved obviously. Besides, the small cracks conduced by the upgrowth stress in the coatings were ameliorated when the rare earth neodymium was added. The improvement mechanism was further discussed.

Microstructures, Tensile Properties and Forming Process of AZ31 Alloy Sheets

2007 ◽  
Vol 546-549 ◽  
pp. 241-244 ◽  
Author(s):  
Yun Qi Yan ◽  
H. Zhang ◽  
Q. Chen ◽  
H. Zhong ◽  
W.P. Weng
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Tensile Properties ◽  
Cell Phone ◽  
Az31 Alloy ◽  
Forming Process ◽  
Fine Grained ◽  
Forming Temperature ◽  
Scanning Electron

Rolling and punching techniques of AZ31 alloy were investigated in this paper. Various rolling experiments were carried out to make fine-grained Mg sheets. Punching tests were conducted at the temperatures range from 70 to 300 oC. The analysis revealed that there existed an excellent warm forming temperature for as-rolled AZ31 alloy. A warm deep punching tool setup using heating elements was designed and manufactured to produce the cell phone. Microstructures were observed using optical and scanning electron microscope equipped with EBSD. The textures in as-rolled and as-annealed specimens attribute to different mechanical properties along the various direction.

Development of Piezo-Spectroscopic Techniques for Nano-Scale Stress Analysis in the Scanning Electron Microscope of Zirconia Bioceramics Based on Rare-Earth Fluorescence

2006 ◽  
Vol 309-311 ◽  
pp. 1215-1218
Author(s):  
Kiyotaka Yamada ◽  
Junji Ikeda ◽  
Giuseppe Pezzotti
Keyword(s):  
Phase Transformation ◽  
Rare Earth ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Spectral Shift ◽  
Spectroscopic Techniques ◽  
Rare Earth Ion ◽  
Fluorescent Band ◽  
Nano Scale ◽  
Scanning Electron

The electro-stimulated luminescence spectrum of a rare-earth ion added to zirconia (ZrO2) lattice was investigated with the aim of using it as a sensor for nano-scale stress (fluorescence piezo-spectroscopy) and phase transformation assessments in a field emission scanning electron microscope (FE-SEM). In this paper, the selected rare-earth fluorescent ion Eu, added to ZrO2 as a raw oxide powder (Eu2O3) before sintering (in the amount of 1.0 wt. %). Spectroscopic results indicated that the spectral shift of some fluorescent band of the selected rare-earth ion was sensitive to residual stress and that the electron-stimulated spectra of Eu2O3-doped ZrO2 in its tetragonal and monoclinic polymorphs were different to each other. Based on these findings, the luminescent substance can be useful as a “stress and phase transformation sensor”, in order to clarify the elementary mechanisms behind synthetic ZrO2.

Micro-Structural Studies of Leached SON-68-Type Glasses

2001 ◽  
Author(s):  
N. Ollier ◽  
G. Panczer ◽  
B. Champagnon ◽  
P. Jollivet
Keyword(s):  
Rare Earth ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Rare Earth Element ◽  
Earth Element ◽  
The Other ◽  
Structural Studies ◽  
Microscopic Features ◽  
Precipitated Phases ◽  
Scanning Electron

Abstract Two types of borosilicate leached SON68-type glasses were studied, one doped with uranium and the other with rare-earth element (Nd, Eu). Photoluminescence and cathodoluminescence properties of U doped samples have been correlated to microscopic features of the corroded glass. Nuclear analysis, Electronic Microprobe and Scanning Electron Microscope investigations revealed the heterogeneous composition of the gels with differentiated phases. Enriched U phases (crystallised or not) and phosphorus precipitated phases in rare earth gel have been detected.

Comparative study of iron ore characterisation using a scanning electron microscope and optical image analysis

2013 ◽  
Vol 122 (4) ◽  
pp. 217-229 ◽  
Author(s):  
E. Donskoi ◽  
J. R. Manuel ◽  
P. Austin ◽  
A. Poliakov ◽  
M. J. Peterson ◽  
...  
Keyword(s):  
Image Analysis ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Comparative Study ◽  
Iron Ore ◽  
Optical Image ◽  
Scanning Electron

Microdiffraction phase identification in the scanning electron microscope (SEM)

2004 ◽  
Vol 19 (2) ◽  
pp. 100-103 ◽  
Author(s):  
R. P. Goehner ◽  
J. R. Michael
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Beam Current ◽  
Electron Diffraction Data ◽  
Specimen Preparation ◽  
Phase Identification ◽  
Electron Backscattered Diffraction ◽  
Backscattered Electron ◽  
Ccd Detectors ◽  
Scanning Electron

The identification of crystallographic phases in the scanning electron microscope (SEM) has been limited by the lack of a simple way to obtain electron diffraction data of an unknown while observing the microstructure of the specimen. With the development of charge coupled device (CCD)-based detectors, backscattered electron Kikuchi patterns, alternately referred to as electron backscattered diffraction (EBSD) patterns, can be easily collected. Previously, EBSD has been limited to crystallographic orientation studies due to the poor pattern quality collected with video rate detector systems. With CCD detectors, a typical EBSD can now be acquired from a micron or submicron sized crystal using an exposure time of 1–10 s with an accelerating voltage of 10–40 kV and a beam current as low as 0.1 nA. Crystallographic phase analysis using EBSD is unique in that the properly equipped SEM permits high magnification images, EBSDs, and elemental information to be collected from bulk specimens. EBSD in the SEM has numerous advantages over other electron beam-based crystallographic techniques. The large angular view (∼70°) provided by EBSD and the ease of specimen preparation are distinct advantages of the technique. No sample preparation beyond what is commonly used for SEM specimens is required for EBSD.

Oxidation of Manganese-Containing Aluminum Alloys Studied by SEM

2014 ◽  
Vol 794-796 ◽  
pp. 1095-1100
Author(s):  
Shawn C. Wilson ◽  
Anne Kvithyld ◽  
Thorvald Abel Engh ◽  
Gabriella Tranell
Keyword(s):  
Electron Microscope ◽  
Chemical Composition ◽  
Scanning Electron Microscope ◽  
Oxide Film ◽  
Current Knowledge ◽  
Sem Analysis ◽  
Muffle Furnace ◽  
Mn Content ◽  
Small Clusters ◽  
Scanning Electron

During remelting of aluminum manganese-containing alloys, some industrial experience has indicateda tendency toward increased oxidation losses when compared to unalloyed Al. A goal of thiswork is to increase current knowledge of oxidation of Mn-containing aluminum. An oxidation studywas performed on 99.99% Al, Al-1%Mn and Al-5%Mn materials in a muffle furnace in air. Theseoxidized materials were analyzed in the Scanning Electron Microscope using Energy Dispersive xraySpectroscopy (EDS) both for chemical composition and to analyze the structure of the oxide thatwas formed. The main findings from the SEM analysis of the oxidized 99.99% Al, Al1%Mn andAl5%Mn materials are: 1) The oxides formed on the Al1Mn and Al5Mn materials contained onlyminute amounts of Mn. However, small clusters of Mn metal were found among the Al2O3 particleson the surface of the Al1Mn and Al5Mn samples. 2) Dissolved Mn increased from the surface to theinterior, and Mn-rich particles were present in the interior of the Al1Mn and Al5Mn samples. 3) Theoxide layer thickness increases with Mn content, and the oxide film is more fragmented.

Scanning Electron Microscope-Cathodoluminescence Analysis of Rare-Earth Elements in Magnets

2016 ◽  
Vol 22 (1) ◽  
pp. 82-86 ◽  
Author(s):  
Susumu Imashuku ◽  
Kazuaki Wagatsuma ◽  
Jun Kawai
Keyword(s):  
Rare Earth ◽  
Electron Microscope ◽  
Hydrochloric Acid ◽  
Scanning Electron Microscope ◽  
Rare Earth Elements ◽  
Luminescence Spectra ◽  
Ndfeb Magnet ◽  
Ndfeb Magnets ◽  
X Ray ◽  
Scanning Electron

AbstractScanning electron microscope-cathodoluminescence (SEM-CL) analysis was performed for neodymium–iron–boron (NdFeB) and samarium–cobalt (Sm–Co) magnets to analyze the rare-earth elements present in the magnets. We examined the advantages of SEM-CL analysis over conventional analytical methods such as SEM-energy-dispersive X-ray (EDX) spectroscopy and SEM-wavelength-dispersive X-ray (WDX) spectroscopy for elemental analysis of rare-earth elements in NdFeB magnets. Luminescence spectra of chloride compounds of elements in the magnets were measured by the SEM-CL method. Chloride compounds were obtained by the dropwise addition of hydrochloric acid on the magnets followed by drying in vacuum. Neodymium, praseodymium, terbium, and dysprosium were separately detected in the NdFeB magnets, and samarium was detected in the Sm–Co magnet by the SEM-CL method. In contrast, it was difficult to distinguish terbium and dysprosium in the NdFeB magnet with a dysprosium concentration of 1.05 wt% by conventional SEM-EDX analysis. Terbium with a concentration of 0.02 wt% in an NdFeB magnet was detected by SEM-CL analysis, but not by conventional SEM-WDX analysis. SEM-CL analysis is advantageous over conventional SEM-EDX and SEM-WDX analyses for detecting trace rare-earth elements in NdFeB magnets, particularly dysprosium and terbium.

scholarly journals ТHЕ ANALYSIS OF NATURE OF DAMAGE OF THE MATRIX MATERIAL, USED IN PRODUCTION OF DIAMOND DRILLING AND STONE-WORKING TOOLS DURING THE DESTRUCTION OF A ROCKS

2021 ◽  
Author(s):  
Olena Vynohradova ◽  
◽  
Oleksandr Vasylchuk ◽  
Anatoly Zakora ◽  
Grygorii Petasyuk ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Chemical Composition ◽  
Scanning Electron Microscope ◽  
Diamond Tool ◽  
Roughness Element ◽  
Matrix Material ◽  
Dynamic Interaction ◽  
Short Term ◽  
The Matrix ◽  
Scanning Electron

In this paper are studied themechanism of matrix damage in rock cutting diamond toolswhen interacting with rock. Earlier, in the sludge obtained during mining with a diamond tool on a block of sandstone of the Torez deposit, using a scanning electron microscope (SEM) ZEISS EVO 50 XVP, equipped with Oxford Instruments` Ultim Max 100 energy-dispersive X-ray analyzer (elemental analysis) particles were found whose chemical composition corresponded to the matrix material of the tool. According to the theory of M.V. Kirpichev, the complete correspondence of all configuration elements of the individual studied matrix particles and rock particles, which the sludge obtained as a result of work of diamond tool testifies to a single mechanism of brittle fracture of both counterbodies during dynamic interaction. However, the nature of the matrix material indentation, remains, unexplored. On the basis of the hypothesis that the damage to the matrix material of a diamond tool is carried out by roughness elements from the side of the rock, the goal was set to investigate the wear products of a diamond-free insert made from material, used as a matrix in a diamond rock-breaking tool with a short-term dynamic contact with cooling with a rock block However, the nature of the matrix material indentation, remains, unexplored. The originality of the method lies in the fact that in this study, the destructive indenters are not diamond grains, which gouge out particles of the rock, but elements of the roughness of the rock, which damage theexperimental cylindrical free-diamond element from NiSn (6%), having a density of 7.875 g/cm3, performed by the method of intensive sintering. The sludge obtained as a result of a short-term interaction of the experimental element and the rotating block of the rock on the bench was examined using a , using aabove-mentioned scanning electron microscope. The spectral analysis of the removed from the sludge particle of matrix material from which the experimental diamond-free element was made, confirmed the conformity of chemical composition of particle to the chemical composition of the matrix material of the experimental diamond-free sample.Full correspondence of all configurational components of a NiSn particle (6%) obtained by the action of a rock roughness element on a diamond-free insert during their dynamic interaction with all configurational components of wear particles of a diamond tool matrix., according to the similarity theory of M.V. Kirpichev, confirms the above-mentioned hypothesis.

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