scholarly journals Stable and Metastable Phase Equilibria Involving the Cu6Sn5 Intermetallic

2021 ◽  
Author(s):  
A. Leineweber ◽  
M. Löffler ◽  
S. Martin
Keyword(s):  
Phase Equilibria ◽  
Electron Backscatter Diffraction ◽  
Metastable Phase ◽  
Stable Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Ordered Phases ◽  
Backscatter Diffraction ◽  
Kinetics Of

Abstract Cu6Sn5 intermetallic occurs in the form of differently ordered phases η, η′ and η′′. In solder joints, this intermetallic can undergo changes in composition and the state of order without or while interacting with excess Cu and excess Sn in the system, potentially giving rise to detrimental changes in the mechanical properties of the solder. In order to study such processes in fundamental detail and to get more detailed information about the metastable and stable phase equilibria, model alloys consisting of Cu3Sn + Cu6Sn5 as well as Cu6Sn5 + Sn-rich melt were heat treated. Powder x-ray diffraction and scanning electron microscopy supplemented by electron backscatter diffraction were used to investigate the structural and microstructural changes. It was shown that Sn-poor η can increase its Sn content by Cu3Sn precipitation at grain boundaries or by uptake of Sn from the Sn-rich melt. From the kinetics of the former process at 513 K and the grain size of the η phase, we obtained an interdiffusion coefficient in η of (3 ± 1) × 10−16 m2 s−1. Comparison of this value with literature data implies that this value reflects pure volume (inter)diffusion, while Cu6Sn5 growth at low temperature is typically strongly influenced by grain-boundary diffusion. These investigations also confirm that η′′ forming below a composition-dependent transus temperature gradually enriches in Sn content, confirming that Sn-poor η′′ is metastable against decomposition into Cu3Sn and more Sn-rich η or (at lower temperatures) η′. Graphic Abstract

Mitrofanovite, Pt3Te4, a new mineral from the East Chuarvy deposit, Fedorovo–Pana intrusion, Kola Peninsula, Russia

2018 ◽  
Vol 83 (4) ◽  
pp. 523-530 ◽  
Author(s):  
Victor V. Subbotin ◽  
Anna Vymazalová ◽  
František Laufek ◽  
Yevgeny E. Savchenko ◽  
Chris J. Stanley ◽  
...  
Keyword(s):  
Kola Peninsula ◽  
Electron Backscatter Diffraction ◽  
New Mineral ◽  
Synthetic Analogue ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structural Identity ◽  
Polarised Light ◽  
Fe Alloys ◽  
Backscatter Diffraction

AbstractMitrofanovite, Pt3Te4, is a new telluride discovered in low-sulfide disseminated ore in the East Chuarvy deposit, Fedorovo–Pana intrusion, Kola Peninsula, Russia. It forms anhedral grains (up to ~20 μm × 50 μm) commonly in intergrowths with moncheite in aggregates with lukkulaisvaaraite, kotulskite, vysotskite, braggite, keithconnite, rustenburgite and Pt–Fe alloys hosted by a chalcopyrite–pentlandite–pyrrhotite matrix. Associated silicates are: orthopyroxene, augite, olivine, amphiboles and plagioclase. Mitrofanovite is brittle; it has a metallic lustre and a grey streak. Mitrofanovite has a good cleavage, along {001}. In plane-polarised light, mitrofanovite is bright white with medium to strong bireflectance, slight pleochroism, and strong anisotropy on non-basal sections with greyish brown rotation tints; it exhibits no internal reflections. Reflectance values for the synthetic analogue of mitrofanovite in air (Ro, Re’ in %) are: 58.4, 54.6 at 470 nm; 62.7, 58.0 at 546 nm; 63.4, 59.1 at 589 nm; and 63.6, 59.5 at 650 nm. Fifteen electron-microprobe analyses of mitrofanovite gave an average composition: Pt 52.08, Pd 0.19, Te 47.08 and Bi 0.91, total 100.27 wt.%, corresponding to the formula (Pt2.91Pd0.02)Σ2.93(Te4.02Bi0.05)Σ4.07 based on 7 atoms; the average of eleven analyses on synthetic analogue is: Pt 52.57 and Te 47.45, total 100.02 wt.%, corresponding to Pt2.94Te4.06. The density, calculated on the basis of the formula, is 11.18 g/cm3. The mineral is trigonal, space group R$\overline 3 $m, with a = 3.9874(1), c = 35.361(1) Å, V = 486.91(2) Å3 and Z = 3. The crystal structure was solved and refined from the powder X-ray-diffraction data of synthetic Pt3Te4. Mitrofanovite is structurally and chemically related to moncheite (PtTe2). The strongest lines in the powder X-ray diffraction pattern of synthetic mitrofanovite [d in Å (I) (hkl)] are: 11.790(23)(003), 5.891(100)(006), 2.851(26)(107), 2.137(16)(1013), 2.039(18)(0114), 1.574(24)(0120), 1.3098(21)(0027). The structural identity of natural mitrofanovite with synthetic Pt3Te4 was confirmed by electron backscatter diffraction measurements on the natural sample. The mineral name is chosen to honour Felix P. Mitrofanov, a Russian geologist who was among the first to discover platinum-group element mineralisation in the Fedorova–Pana complex.

scholarly journals Effects of Annealing Temperature on Recrystallization Texture and Microstructure Uniformity of High Purity Tantalum

Metals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 75 ◽  
Author(s):  
Jialin Zhu ◽  
Chao Deng ◽  
Yahui Liu ◽  
Nan Lin ◽  
Shifeng Liu
Keyword(s):  
Low Temperature ◽  
Electron Backscatter Diffraction ◽  
Stored Energy ◽  
X Ray Diffraction ◽  
Center Layer ◽  
X Ray ◽  
Texture Intensity ◽  
Low Temperature Annealing ◽  
Transmission Electron ◽  
Backscatter Diffraction

One hundred and thirty-five degree clock rolling significantly improves the texture homogeneity of tantalum sheets along the thickness, but a distinctly fragmented substructure is formed within {111} (<111>//normal direction (ND)) and {100} (<100>//ND) deformation grains, which is not suitable to obtain a uniform recrystallization microstructure. Thus, effects of different annealing temperatures on the microstructure and texture heterogeneity of tantalum sheets along the thickness were investigated by X-ray diffraction (XRD), electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). Results show that the texture distribution along θ-fiber and γ-fiber is irregular and many large grains with {111} orientation develop during annealing at high temperature. However, low-temperature annealing can not only weaken the texture intensity in the surface and the center layer but also introduce a more uniform grain size distribution. This result can be attributed to the subgrain-nucleation-dominated recrystallization mechanism induced by recovery at low temperature, and moreover, a considerable decline of recrystallization driving force resulting from the release of stored energy in the deformation matrix.

scholarly journals Effect of TiO2-Nanoparticles on Ni Electrodeposition on Copper Wire

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 406
Author(s):  
Samiha Saad ◽  
Zakaria Boumerzoug ◽  
Anne Laure Helbert ◽  
François Brisset ◽  
Thierry Baudin
Keyword(s):  
Surface Morphology ◽  
Tio2 Nanoparticles ◽  
Vickers Microhardness ◽  
Electron Backscatter Diffraction ◽  
Copper Wire ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electron Backscatter ◽  
Electrodeposited Nickel ◽  
Backscatter Diffraction

The objective of this work is to study, on a copper wire, the effect of TiO2-nanoparticles on electrodeposited nickel. Both the microstructure and surface morphology (texture) of the coating were investigated. This deposit is obtained from baths of sulfated electroplating Watts. The Ni-TO2 composite coating is deposited at a temperature of 45 °C. The composite deposit is prepared by adding nanoparticles of TiO2 to the electrolyte. The characterization has been carried out by X-ray diffraction, scanning electron microscopy, microhardness measurements, and electron backscatter diffraction (EBSD). Vickers microhardness was used to characterize the mechanical properties of the electrodeposited nickel. The results showed the effects of the TiO2 on the composition, the surface morphology, and the hardness of the deposited layer. However, there was not an effect of TiO2 nanoparticles on texture.

scholarly journals Phase Equilibria in the Nb-Rich Region of Al-Nb-Sn at 900 and 1200 °C

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2759 ◽  
Author(s):  
Ioannis Papadimitriou ◽  
Claire Utton ◽  
Panos Tsakiropoulos
Keyword(s):  
Crystal Structure ◽  
Phase Equilibria ◽  
Ternary Phase ◽  
X Ray Diffraction ◽  
High Solubility ◽  
Rich Region ◽  
X Ray ◽  
Heat Treated ◽  
Aero Engine ◽  
Scanning Electron

The Al-Nb-Sn phase diagram was studied experimentally in the Nb-rich region to provide important phase equilibria information for alloy design of Nb-silicide based materials for aero engine applications. Three alloys were produced: Nb-17Al-17Sn, Nb-33Al-13Sn and Nb-16Al-20Sn (at.%). As-cast and heat-treated alloys (900 and 1200 °C) were analysed using XRD (X-ray diffraction) and SEM/EDS (scanning electron microscopy/ electron dispersive x-ray spectroscopy). Tin showed a high solubility in Nb2Al, reaching up to 21 at.% in the Sn-rich areas, substituting for Al atoms. Tin and Al also substituted for each other in the A15 phases (Nb3Al and Nb3Sn). Tin showed limited solubility in NbAl3, not exceeding 3.6 at.% as it substituted Al atoms. The solubility of Al in NbSn2 varied from 4.8 to 6.8 at.%. A ternary phase, Nb5Sn2Al with the tI32 W5Si3 crystal structure, was found to be stable. This phase was observed in the 900 °C heat-treated samples, but not in the 1200 °C heated samples.

X-ray diffraction contrast tomography: a novel technique for three-dimensional grain mapping of polycrystals. II. The combined case

2008 ◽  
Vol 41 (2) ◽  
pp. 310-318 ◽  
Author(s):  
Greg Johnson ◽  
Andrew King ◽  
Marcelo Goncalves Honnicke ◽  
J. Marrow ◽  
Wolfgang Ludwig
Keyword(s):  
Electron Backscatter Diffraction ◽  
Three Dimensional ◽  
Real Data ◽  
X Ray Diffraction ◽  
Data Set ◽  
Transmitted Beam ◽  
X Ray ◽  
Diffraction Contrast ◽  
Simultaneous Acquisition ◽  
Backscatter Diffraction

By simultaneous acquisition of the transmitted and the diffracted beams, the applicability of the previously introduced diffraction contrast tomography technique [Ludwig, Schmidt, Lauridsen & Poulsen (2008).J. Appl. Cryst.41, 302–309] can be extended to the case of undeformed polycrystalline samples containing more than 100 grains per cross section. The grains are still imaged using the occasionally occurring diffraction contribution to the X-ray attenuation coefficient, which can be observed as a reduction in the intensity of the transmitted beam when a grain fulfils the diffraction condition. Automating the segmentation of the extinction spot images is possible with the additional diffracted beam information, even in the presence of significant spot overlap. By pairing the corresponding direct (`extinction') and diffracted beam spots a robust sorting and indexing approach has been implemented. The analysis procedure is illustrated on a real data set and the result is validated by comparison with a two-dimensional grain map obtained by electron backscatter diffraction.

Surface Crystallization of Cordierite from Glass Studied by High-Temperature X-ray Diffraction and Electron Backscatter Diffraction (EBSD)

2011 ◽  
Vol 11 (10) ◽  
pp. 4660-4666 ◽  
Author(s):  
Wolfgang Wisniewski ◽  
Carlos André Baptista ◽  
Matthias Müller ◽  
Günter Völksch ◽  
Christian Rüssel
Keyword(s):  
High Temperature ◽  
Electron Backscatter Diffraction ◽  
Surface Crystallization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electron Backscatter ◽  
Backscatter Diffraction

scholarly journals Microstrain distribution mapping on CuInSe2 thin films by means of electron backscatter diffraction, X-ray diffraction, and Raman microspectroscopy

2016 ◽  
Vol 169 ◽  
pp. 89-97 ◽  
Author(s):  
Norbert Schäfer ◽  
Angus J. Wilkinson ◽  
Thomas Schmid ◽  
Aimo Winkelmann ◽  
Gilbert A. Chahine ◽  
...  
Keyword(s):  
Thin Films ◽  
Electron Backscatter Diffraction ◽  
Raman Microspectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electron Backscatter ◽  
Distribution Mapping ◽  
Backscatter Diffraction

Influence of Mechanical Activation on the Phase Formation in the Synthesis of Cordierite from Talc and Andalusite

2019 ◽  
Vol 798 ◽  
pp. 235-241
Author(s):  
Chatcharin Vairojanakit ◽  
Sujarinee Sinchai
Keyword(s):  
Mechanical Activation ◽  
Phase Formation ◽  
Stoichiometric Composition ◽  
Synthesis Temperature ◽  
Thermal Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Kinetics Of ◽  
Grinding Time

Cordierite is known as a leading candidate material for many applications. In this study, mechanical activation assisted synthesis of cordierite using andalusite as a starting material was attempted and phase formation of powder obtained from the heat treatment of talc-andalusite-silica system was investigated. The stoichiometric composition of cordierite (2MgO·2Al2O3·5SiO2) was prepared and ground in planetary ball mill at the rotational speed of 300 and 500 rpm for 0, 30, 60 and 90 min. The powder mixtures were heat treated in air at the temperature ranging from 1150 to 1350°C for 2 hours. Thermal reaction, phase present and microstructure of the starting materials and synthesized products were analyzed by differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. It was found that cordierite phase increased with the grinding time and speed and synthesis temperature. The kinetics of phase formation in this system were also discussed.

The Occurrence of a Peripheral Coarse Grain Zone (PCGZ) in Extruded Bars of AA 7108

2021 ◽  
Vol 1016 ◽  
pp. 1141-1146
Author(s):  
Saul Hissaci de Souza ◽  
Ronald Lesley Plaut ◽  
Nelson Batista de Lima ◽  
Rene Ramos de Oliveira ◽  
Angelo Fernando Padilha
Keyword(s):  
Electron Backscatter Diffraction ◽  
Microstructural Analysis ◽  
Polarized Light ◽  
Coarse Grain ◽  
X Ray Diffraction ◽  
Rectangular Section ◽  
X Ray ◽  
Analysis Techniques ◽  
Coarse Grains ◽  
Backscatter Diffraction

Industrial-scale extruded profiles of AA 7108 with a rectangular section (25.60 mm x 15.95 mm) were used in this investigation. Some complementary microstructural analysis techniques, such as polarized light microscopy, EBSD (Electron Backscatter Diffraction) and X-ray diffraction were used to characterize the microstructure, focusing on the PCG zone. It was observed that the extruded profiles presented a totally recrystallized microstructure and a 300 μm layer of peripheral coarse grains. Additionally, the results showed that the PCGZ predominant grain orientation {311} <110> differs from the texture below the PCGZ (Goss and Cube components).

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