scholarly journals Operational Properties of the Cermet Electro-Spark Coatings after Laser Treatment – Technology and Application

2019 ◽  
Vol 1 (1) ◽  
pp. 797-804
Author(s):  
Norbert Radek ◽  
Jacek Pietraszek ◽  
Janusz Konstanty
Keyword(s):  
Laser Treatment ◽  
Treatment Process ◽  
Sliding Friction ◽  
Protective Coatings ◽  
Structure Refinement ◽  
X Ray Diffraction ◽  
Roughness Measurement ◽  
Treatment Technology ◽  
X Ray ◽  
Hardness Tests

AbstractThe paper is concerned with determining the influence of the laser treatment process on the properties of electro-spark coatings. The properties of the coatings after laser treatment were assessed based on following methods: microstructure and X-ray diffraction analysis, adhesion tests, roughness measurement, hardness tests, tribological properties and application tests. The tests were carried out on WC-Co coating (the anode) obtained by electro-spark deposition over carbon steel C45 (the cathode) and molten with a laser beam. The coatings were deposited by means of the EIL-8A and they were laser treated with the Nd:YAG. The tests show that the laser-treated electro-spark deposited WC-Co coatings are characterized by lower hardness, higher seizure resistance, roughness and adhesion. The laser treatment process causes the homogenization of the chemical composition, the structure refinement and the healing of microcracks and pores of the electro-spark deposited coatings. Laser treated electro-spark deposited coatings are likely to be applied in sliding friction pairs and as protective coatings.

scholarly journals The Electro-Spark Deposited WC-Cu Coatings Modified by Laser Treatment / Powłoki WC-Cu Naniesione Elektroiskrowo I Modyfikowane Obróbką Laserową

2015 ◽  
Vol 60 (4) ◽  
pp. 2579-2584 ◽  
Author(s):  
N. Radek ◽  
J. Konstanty ◽  
M. Scendo
Keyword(s):  
Corrosion Resistance ◽  
Laser Treatment ◽  
Sliding Friction ◽  
Protective Coatings ◽  
Structure Refinement ◽  
X Ray Diffraction ◽  
Properties Of Coatings ◽  
X Ray ◽  
Resistance Surface ◽  
Composition Structure

The main objective of the present work was to determine the influence of laser treatment on microstructure, X-ray diffraction, microhardness, surface geometric structure and roughness, corrosion resistance and tribological properties of coatings deposited on C45 carbon steel by the electro-spark deposition (ESD) process. The studies were conducted using WC-Cu electrodes produced by the powder metallurgy route. The tests show that the laser-treated electro-spark deposited WC-Cu coatings are characterized by higher corrosion resistance, surface roughness and seizure resistance which come at the expense of lower microhardness. The laser treatment process causes the homogenization of the chemical composition, structure refinement and healing of microcracks and pores of the electro-spark deposited coatings. Laser treated ESD coatings can be applied in sliding friction pairs and as protective coatings.

Structure refinement of (Al, Zn)49Mg32-type phases by single-crystal X-ray diffraction

2000 ◽  
Vol 294-296 ◽  
pp. 327-330 ◽  
Author(s):  
W. Sun ◽  
F.J. Lincoln ◽  
K. Sugiyama ◽  
K. Hiraga
Keyword(s):  
Single Crystal ◽  
Structure Refinement ◽  
X Ray Diffraction ◽  
X Ray

Rare-earth crystal chemistry of thalénite-(Y) from different environments

2018 ◽  
Vol 82 (2) ◽  
pp. 313-327
Author(s):  
Markus B. Raschke ◽  
Evan J. D. Anderson ◽  
Jason Van Fosson ◽  
Julien M. Allaz ◽  
Joseph R. Smyth ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Element ◽  
Earth Element ◽  
Spatial Scales ◽  
Structure Refinement ◽  
X Ray Diffraction ◽  
Heavy Rare Earth ◽  
Heavy Rare Earth Element ◽  
X Ray ◽  
Golden Horn

ABSTRACTThalénite-(Y), ideally Y3Si3O10F, is a heavy-rare-earth-rich silicate phase occurring in granite pegmatites that may help to illustrate rare-earth element (REE) chemistry and behaviour in natural systems. The crystal structure and mineral chemistry of thalénite-(Y) were analysed by electron microprobe analysis, X-ray diffraction and micro-Raman spectroscopy from a new locality in the peralkaline granite of the Golden Horn batholith, Okanogan County, Washington State, USA, in comparison with new analyses from the White Cloud pegmatite in the Pikes Peak batholith, Colorado, USA. The Golden Horn thalénite-(Y) occurs as late-stage sub-millimetre euhedral bladed transparent crystals in small miarolitic cavities in an arfvedsonite-bearing biotite granite. It exhibits growth zoning with distinct heavy-rare-earth element (HREE) vs. light-rare-earth element (LREE) enriched zones. The White Cloud thalénite-(Y) occurs in two distinct anhedral and botryoidal crystal habits of mostly homogenous composition. In addition, minor secondary thalénite-(Y) is recognized by its distinct Yb-rich composition (up to 0.8 atoms per formula unit (apfu) Yb). Single-crystal X-ray diffraction analysis and structure refinement reveals Y-site ordering with preferential HREE occupation of Y2 vs. Y1 and Y3 REE sites. Chondrite normalization shows continuous enrichment of HREE in White Cloud thalénite-(Y), in contrast to Golden Horn thalénite-(Y) with a slight depletion of the heaviest REE (Tm, Yb and Lu). The results suggest a hydrothermal origin of the Golden Horn miarolitic thalénite-(Y), compared to a combination of both primary magmatic followed by hydrothermal processes responsible for the multiple generations over a range of spatial scales in White Cloud thalénite-(Y).

Arrheniusite-(Ce), CaMg[(Ce7Y3)Ca5](SiO4)3(Si3B3O18)(AsO4)(BO3)F11, a New Member of the Vicanite Group, from the Östanmossa Mine, Norberg, Sweden

2021 ◽  
Author(s):  
Dan Holtstam ◽  
Luca Bindi ◽  
Paola Bonazzi ◽  
Hans-Jürgen Förster ◽  
Ulf B. Andersson
Keyword(s):  
Structure Refinement ◽  
New Mineral ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Calculated Density ◽  
Epma Data ◽  
X Ray ◽  
Cell Parameters ◽  
Greenish Yellow ◽  
The Ideal

ABSTRACT Arrheniusite-(Ce) is a new mineral (IMA 2019-086) from the Östanmossa mine, one of the Bastnäs-type deposits in the Bergslagen ore region, Sweden. It occurs in a metasomatic F-rich skarn, associated with dolomite, tremolite, talc, magnetite, calcite, pyrite, dollaseite-(Ce), parisite-(Ce), bastnäsite-(Ce), fluorbritholite-(Ce), and gadolinite-(Nd). Arrheniusite-(Ce) forms anhedral, greenish-yellow translucent grains, exceptionally up to 0.8 mm in diameter. It is optically uniaxial (–), with ω = 1.750(5), ε = 1.725(5), and non-pleochroic in thin section. The calculated density is 4.78(1) g/cm3. Arrheniusite-(Ce) is trigonal, space group R3m, with unit-cell parameters a = 10.8082(3) Å, c = 27.5196(9) Å, and V = 2784.07(14) Å3 for Z = 3. The crystal structure was refined from X-ray diffraction data to R1 = 3.85% for 2286 observed reflections [Fo > 4σ(Fo)]. The empirical formula for the fragment used for the structural study, based on EPMA data and results from the structure refinement, is: (Ca0.65As3+0.35)Σ1(Mg0.57Fe2+0.30As5+0.10Al0.03)Σ1[(Ce2.24Nd2.13La0.86Gd0.74Sm0.71Pr0.37)Σ7.05(Y2.76Dy0.26Er0.11Tb0.08Tm0.01Ho0.04Yb0.01)Σ3.27Ca4.14]Σ14.46(SiO4)3[(Si3.26B2.74)Σ6O17.31F0.69][(As5+0.65Si0.22P0.13)Σ1O4](B0.77O3)F11; the ideal formula obtained is CaMg[(Ce7Y3)Ca5](SiO4)3(Si3B3O18)(AsO4)(BO3)F11. Arrheniusite-(Ce) belongs to the vicanite group of minerals and is distinct from other isostructural members mainly by having a Mg-dominant, octahedrally coordinated site (M6); it can be considered a Mg-As analog to hundholmenite-(Y). The threefold coordinated T5 site is partly occupied by B, like in laptevite-(Ce) and vicanite-(Ce). The mineral name honors C.A. Arrhenius (1757–1824), a Swedish officer and chemist, who first discovered gadolinite-(Y) from the famous Ytterby pegmatite quarry.

scholarly journals Redetermination of Sr2PdO3 from single-crystal X-ray data

2019 ◽  
Vol 75 (1) ◽  
pp. 30-32
Author(s):  
Gohil S. Thakur ◽  
Hans Reuter ◽  
Claudia Felser ◽  
Martin Jansen
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Data ◽  
Structure Refinement ◽  
Structure Type ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Cell Parameters ◽  
Anisotropic Displacement Parameters

The crystal structure redetermination of Sr2PdO3 (distrontium palladium trioxide) was carried out using high-quality single-crystal X-ray data. The Sr2PdO3 structure has been described previously in at least three reports [Wasel-Nielen & Hoppe (1970). Z. Anorg. Allg. Chem. 375, 209–213; Muller & Roy (1971). Adv. Chem. Ser. 98, 28–38; Nagata et al. (2002). J. Alloys Compd. 346, 50–56], all based on powder X-ray diffraction data. The current structure refinement of Sr2PdO3, as compared to previous powder data refinements, leads to more precise cell parameters and fractional coordinates, together with anisotropic displacement parameters for all sites. The compound is confirmed to have the orthorhombic Sr2CuO3 structure type (space group Immm) as reported previously. The structure consists of infinite chains of corner-sharing PdO4 plaquettes interspersed by SrII atoms. A brief comparison of Sr2PdO3 with the related K2NiF4 structure type is given.

scholarly journals Crystal structure refinement of magnesium zinc divanadate, MgZnV2O7, from powder X-ray diffraction data

2021 ◽  
Vol 77 (6) ◽  
pp. 588-591
Author(s):  
Stephanie J. Hong ◽  
Jun Li ◽  
Mas A. Subramanian
Keyword(s):  
Crystal Structure ◽  
Diffraction Data ◽  
Structure Refinement ◽  
Atomic Ratio ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Wyckoff Position ◽  
Distorted Trigonal Bipyramidal

The crystal structure of magnesium zinc divanadate, MgZnV2O7, was determined and refined from laboratory X-ray powder diffraction data. The title compound was synthesized by a solid-state reaction at 1023 K in air. The crystal structure is isotypic with Mn0.6Zn1.4V2O7 (C2/m; Z = 6) and is related to the crystal structure of thortveitite. The asymmetric unit contains two metal sites with statistically distributed magnesium and zinc atoms with the atomic ratio close to 1:1. One (Mg/Zn) metal site (M1) is located on Wyckoff position 8j and the other (M2) on 4h. Three V sites (all on 4i), and eight O (three 8j, four 4i, and one 2b) sites complete the asymmetric unit. The structure is an alternate stacking of V2O7 layers and (Mg/Zn) atom layers along [20\overline{1}]. It is distinct from other related structures in that each V2O7 layer consists of two groups: a V2O7 dimer and a V4O14 tetramer. Mixed-occupied M1 and M2 are coordinated by oxygen atoms in distorted trigonal bipyramidal and octahedral sites, respectively.

Characterisation of Chemical Vapour Deposited AlHfN Coatings

2020 ◽  
Vol 405 ◽  
pp. 33-39
Author(s):  
Elisabeth Rauchenwald ◽  
Mario Lessiak ◽  
Ronald Weissenbacher ◽  
Sabine Schwarz ◽  
Roland Haubner
Keyword(s):  
Electron Microscopy ◽  
Protective Coatings ◽  
Cutting Tools ◽  
Chemical Vapour ◽  
Gas Composition ◽  
X Ray Diffraction ◽  
Multilayer Systems ◽  
X Ray ◽  
Transmission Electron ◽  
Hcl Gas

Chemical vapour deposited HfN can be utilised as a component of multilayer systems in protective coatings on cutting tools. In this study, related AlHfN coatings were synthesized through a reaction of metallic hafnium and aluminium with HCl gas forming gaseous HfCl4 and AlCl3, which were subsequently transported into a heated coating reactor. Via high temperatures and separately introduced NH3 and N2 as reaction gases, AlHfN coatings were deposited on hardmetal inserts. By varying the ratio between AlCl3 and HfCl4, compositionally different AlHfN coatings were examined. Additionally, surface morphology, composition as well as crystalline phases of the obtained coatings were analysed by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction. Finally, the microstructure of the cross section of a coating was investigated via transmission electron microscopy. The observations revealed a great impact of the gas composition on the morphology and crystal structures of the coatings. Within the layer, the growth of columnar microstructures was detected. Additionally, the formation of an amorphous HfN intermediate layer between the substrate and the AlHfN with a thickness of approximately 2 nm was found.

Mechanical Behavior of the Cr3C2 Compound at High Pressure and High Temperature

2015 ◽  
Vol 1120-1121 ◽  
pp. 1187-1193 ◽  
Author(s):  
Bin Li Jiang ◽  
Zi Li Kou ◽  
De Jiang Ma ◽  
Yong Kun Wang ◽  
Chun Xia Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
High Pressure ◽  
Relative Density ◽  
X Ray Diffraction ◽  
Density Measurements ◽  
X Ray ◽  
Hardness Tests ◽  
Novel Method ◽  
Heat Preservation

In the present study, we present a novel method to sinter Cr3C2 powders under high pressure without any addittives. The sintering Cr3C2 samples were charaterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), relative density measurements, Vicker’s hardness tests and Fracture toughness tests. The reasults show that Cr3C2 powders could be sintered to be bulk under the conditions of 3-5 GPa, 800-1200 °C and the heat preservation for 15 min. Moreover, the sintering body of Cr3C2 compound with the relative density of 99.84% by simultaneously tuning the pressure-temperature conditions exhibited excellent mechanical properties: a Vickers hardness of 20.3 GPa and a fracture toughness of ~8.9 MPam1/2. These properties were much higher than that by using the previous methods. The temperature condition obtained good mechanical properties in the experiment was about 1/3 lower than that using any other methods owing to the high pressure.

Structure Refinement of CePtSi and Hydrogenation Behavior of CePdGe, CePtSi and CePtGe

2007 ◽  
Vol 62 (4) ◽  
pp. 613-616 ◽  
Author(s):  
Wilfried Hermes ◽  
Ute Ch. Rodewald ◽  
Bernard Chevalier ◽  
Rainer Pötgena
Keyword(s):  
Single Crystal ◽  
Diffraction Data ◽  
Structure Refinement ◽  
Three Dimensional ◽  
Subsequent Annealing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydride Formation ◽  
Arc Melting ◽  
Cerium Compounds

The intermetallic cerium compounds CePdGe, CePtSi, and CePtGe were synthesized from the elements by arc-melting and subsequent annealing. The structure of CePtSi was refined from single crystal X-ray diffraction data: LaPtSi-type (ordered α-ThSi2 version), 141md, a = 419.6(1) and c = 1450.0(5) pm, wR2 = 0.0490, 362 F2 values and 16 variables. The Pt-Si distances within the three-dimensional [PtSi] network are 242 pm, indicating strong Pt-Si interactions. Hydrogenation of the three compounds at 623 K and 4 MPa H2 gave no indication for hydride formation.

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