Phase equilibria in the BaTiO3–La2TiO5–TiO2 system

1998 ◽  
Vol 13 (5) ◽  
pp. 1327-1334 ◽  
Author(s):  
Srečo Škapin ◽  
Drago Kolar ◽  
Danilo Suvorov ◽  
Zoran Samardžija
Keyword(s):  
Solid Solution ◽  
Electron Probe ◽  
Ternary Solid Solution ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
Binary Solid Solution ◽  
Subsolidus Phase ◽  
X Ray ◽  
Tie Lines ◽  
Scanning Electron

Subsolidus phase relations in the BaTiO3–La2TiO5–TiO2 part of the ternary BaO–La2O3–TiO2 system at 1300 °C in air were determined. The phases were characterized by x-ray diffraction, scanning electron microscopy, and electron probe wavelength dispersive spectroscopic microanalysis. A combination of techniques was employed because of insensitivity in detecting secondary phases by x-ray diffraction. The location and extent of Ba6−xLa8+2x/3Ti18O54 ternary solid solution 0.2(1) ⩽ x ⩽ 2.3(1) and Ba1−yLayTi1−y/4 (VTi)y/4O3 binary solid solution 0 ⩽ y ⩽ 0.3 at 1300 °C was established. Tie lines between various barium polytitanates with a sequence of Ba6−xLa8+2x/3Ti18O54 solid solution regions were determined.

The SEM and EDS Energy Spectrum Analysis of a Beach Placer

2010 ◽  
Vol 158 ◽  
pp. 273-280
Author(s):  
Jun Qiu ◽  
Xian Jun Lu ◽  
Ping Chen ◽  
Shu Gang Hu ◽  
Gui Fang Wang
Keyword(s):  
Solid Solution ◽  
Energy Spectrum ◽  
Chemical Analysis ◽  
Electron Probe ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
X Ray ◽  
Metallic Mineral ◽  
Scanning Electron Microscopic ◽  
Scanning Electron

In order to study the phase of Fe and Ti in a beach placer , different methods such as the X-ray diffraction analysis, chemical analysis, scanning electron microscopic , electron probe microanalysis are used to study the characteristics of the beach placer . The research results show the major metallic mineral in the beach placer is titanic magnetite, EDS and energy spectrum map features of which indicate that the vast majority of titanic magnetite contain a certain amount of Ti , the two elements of Fe and Ti take on closely symbiosis and distribute more evenly in titanic magnetite. The Ti exists in the Magnetite lattice in form of isomorphism. The theoretical highest grade of Fe and Ti in the separated Magnetic concentrate are 66.02per cent and 4.86 per cent respectively. In addition, the beach placer contains a small quantity of Ilmenite which is hysterogenic and exists in the form of fine solid solution separation structure in the titanic magnetite

scholarly journals Znx-1CuxMn2O4 Spinels; Synthesis, Structural Characterization and Electrical Evaluation

2019 ◽  
Vol 54 (1) ◽  
Author(s):  
Francisco Méndez-Martínez ◽  
Federico González ◽  
Enrique Lima ◽  
Pedro Bosch ◽  
Heriberto Pfeiffer
Keyword(s):  
Impedance Spectroscopy ◽  
Structural Characterization ◽  
Morphological Changes ◽  
Secondary Phases ◽  
Varistor Ceramic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Copper Addition ◽  
Partial Inverse ◽  
Scanning Electron

This work presents the structural characterization and electrical evaluation of Znx-1CuxMn2O4 spinels, which are materials presented as secondary phases into the varistor ceramic systems. Samples were analyzed by X-ray diffraction, solid-state nuclear magnetic resonance, infrared spectroscopy, scanning electron microscopy and impedance spectroscopy. Although, the addition of copper to the ZnMn2O4 spinel did not produce morphological changes, the structure and electrical behaviors changed considerably. Structurally, copper addition induced the formation of partial inverse spinels, and its addition increases significantly the electrical conductivity. Therefore, the formation of Znx-1CuxMn2O4 spinels, as secondary phases into the varistor materials, may compromise significantly the varistor efficiency.   Ceramic, Impedance Spectroscopy, spinel, Varistor, XRD.

Interaction between Two Ni-Base Alloys and Ceramic Moulds

2013 ◽  
Vol 747-748 ◽  
pp. 765-771 ◽  
Author(s):  
Jian Sheng Yao ◽  
Ding Zhong Tang ◽  
Xiao Guang Liu ◽  
Cheng Bo Xiao ◽  
Xin Li ◽  
...  
Keyword(s):  
Solid Solution ◽  
Interface Reaction ◽  
Vapour Phase ◽  
Optical Microscope ◽  
Solution Phase ◽  
Solid Solution Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron ◽  
Reaction Surfaces

The interfacial reactions between ceramic moulds and DZ417G and DZ125 superalloys were investigated. The microstructure and composition of the interface region were observed by optical microscope, X-ray diffraction and scanning electron microscope with energy dispersive spectroscopy. The results showed that (Al1-xCrx)2O3solid solution phase with pink color was formed from the dissolution of Cr2O3and Al2O3and vapour phase, which was transferred to the reaction surfaces. The reaction layer thicknesses of DZ417G and DZ125 alloys were about in the range of 40-50μm. The interface reaction product between DZ417G alloy and ceramic mould was TiO2and the product between DZ125 alloy and ceramic mould was HfO2.

Effect of Synthesis Conditions and Actinide Contents on Phase Composition of Actinide Bearing Ceramics

2003 ◽  
Vol 807 ◽  
Author(s):  
A. G. Ptashkin ◽  
S. V. Stefanovsky ◽  
S. V. Yudintsev ◽  
S. A. Perevalov
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Phase Composition ◽  
Fluorite Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Synthesis Conditions ◽  
Reducing Conditions ◽  
Dispersive System ◽  
Scanning Electron

ABSTRACTPu-bearing zirconolite and pyrochlore based ceramics were prepared by melting under oxidizing and reducing conditions at 1550 °C. 239Pu content in the samples ranged between ∼10 and ∼50 wt.%. Phase composition of the ceramics and Pu partitioning were studied using X-ray diffraction (XRD) and scanning electron microscopy with energy dispersive system (SEM/EDS). Major phases in the samples were found to be the target zirconolite and pyrochlore as well as a cubic fluorite structure oxide. Normally the Pu content in the Pu host phases was 10–12 wt.%. This corresponds to the Pu content recommended for matrices for immobilization of excess weapons plutonium. At higher Pu content (up to 50 wt.%) additional phases, such as a PuO2-based cubic fluorite-structured solid solution, perovskite, and rutile were found.

Study on Microstructure and Property of Diffusion-Bonded Mo-Cu Joints

2012 ◽  
Vol 508 ◽  
pp. 178-182
Author(s):  
Jian Zhang ◽  
Guo Qiang Luo ◽  
Mei Juan Li ◽  
Qiang Shen ◽  
Lian Meng Zhang
Keyword(s):  
Electron Microscopy ◽  
Mechanical Property ◽  
Tensile Strength ◽  
Electron Probe ◽  
Bonding Process ◽  
Interfacial Structure ◽  
X Ray Diffraction ◽  
Strength Measurement ◽  
X Ray ◽  
Scanning Electron

Mo and Cu Were Bonded Successfully by Means of Vacuum Diffusion Bonding. The Interfacial Structure of the Joints Was Studied by Scanning Electron Microscopy (SEM), Electron Probe Microanalysis (EPMA), Energy Dispersive X-Ray Spectrometer (EDS) and X-Ray Diffraction (XRD), the Mechanical Property Is Tested by Tensile Strength Measurement. The Results Showed that the Differentatoms Diffused to each other in the Bonding Process. A Mo-Cu Solid Solution Was Formed in the Joint and with No Intermetallic Compounds. The Tensile Strength of the Joint Increased with the Increasing of Temperature, however, while the Holding Time Increased, the Strength Increased in the First Stages and then Decreases. It Were Observed that the Fracture Mode of the Joints Was a Brittle Fracture.

Estimation of Interdiffusivities of the Pseudo NiAl Binary Phase Formed in a Nickel-based Superalloy by Pack Cementation

2005 ◽  
Vol 20 (9) ◽  
pp. 2340-2347 ◽  
Author(s):  
H. Wei ◽  
X.F. Sun ◽  
Q. Zheng ◽  
H.R. Guan ◽  
Z.Q. Hu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Probe ◽  
Pack Cementation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Binary Phase ◽  
Nickel Based Superalloy ◽  
Transmission Electron ◽  
Scanning Electron

The pseudo NiAl binary phase was formed in a nickel-based superalloy by pack cementation. Scanning electron microscopy, transmission electron microscopy, x-ray diffraction, electron probe microanalysis, and positron annihilation technique were used to characterize the pseudo NiAl binary phase. Based on reasonable assumptions, the chemical interdiffusivities of the pseudo NiAl binary phase were then assessed by means of the modified Wagner’s method. The results showed that the chemical interdiffusivities of the pseudo NiAl binary phase were about two orders of magnitude lower than those reported by others. The analysis indicated that the change in thermodynamic properties due to the additions of the microalloying atoms originally present in a superalloy could be responsible mainly for a decrease in chemical interdiffusivities.

Nanoporous Ni and Ni-Cu Fabricated by Dealloying

2009 ◽  
Vol 1228 ◽  
Author(s):  
Masataka Hakamada ◽  
Yasumasa Chino ◽  
Mamoru Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Noble Metals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
The Difference ◽  
20 Nm ◽  
Good Workability ◽  
Scanning Electron

AbstractMetallic nanoporous architecture can be spontaneously attained by dealloying of a binary alloy. The nanoporous architecture can be often fabricated in noble metals such as Au and Pt. In this study, nanoporous Ni, Ni-Cu are fabricated by dealloying rolled Ni-Mn and Cu-Ni-Mn alloys, respectively. Unlike conventional Raney nickel composed of brittle Ni-Al or Cu-Al intermetallic compounds, the initial alloys had good workability probably because of their fcc crystal structures. After the electrolysis of the alloys in (NH4)2SO4 aqueous solution, nanoporous architectures of Ni and Ni-Cu with pore and ligament sizes of 10–20 nm were confirmed by scanning electron microscopy and transmission electron microscopy. X-ray diffraction analyses suggested that Ni and Cu atoms form a homogeneous solid solution in the Ni-Cu nanoporous architecture. The ligament sizes of nanoporous Ni and Ni-Cu were smaller than that of nanoporous Cu, reflecting the difference between diffusivities of Ni and Cu at solid/electrolyte interface. Ni can reduce the pore and ligament sizes of resulting nanoporous architecture when added to initial Cu-Mn alloys.

scholarly journals Crystallization of Bi–Sr–Ca–Cu–O glasses in oxygen

1992 ◽  
Vol 7 (7) ◽  
pp. 1658-1671 ◽  
Author(s):  
T.G. Holesinger ◽  
D.J. Miller ◽  
L.S. Chumbley
Keyword(s):  
Electron Microscopy ◽  
Crystallization Process ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
X Ray ◽  
Partial Crystallization ◽  
Full Conversion ◽  
Limited Process ◽  
Step Crystallization ◽  
Scanning Electron

A detailed study of the crystallization process for compositions near Bi2Sr2Ca1Cu2Oy was undertaken using differential thermal analysis (DTA), transmission and scanning electron microscopy (TEM and SEM), and x-ray diffraction (XRD). Glasses prepared by a splat-quench technique were free of secondary phases in most cases. A two-step crystallization process in oxygen was observed in which partial crystallization of the glass occurs initially with the nucleation of “2201” and Cu2O, and is completed with the formation of SrO, CaO, and Bi2Sr3−xCaxOy. No specific thermal event could be associated with the formation of the “2212” phase. Rather, formation occurs via conversion of 2201 into 2212. This was a kinetically limited process at temperatures below 800 °C as other phases were found to evolve in addition to the 2212 phase during extended anneals. In contrast, a nearly full conversion to the 2212 phase occurred after only 1 min of annealing at 800 °C and above. However, changes in resistivity data, secondary phases, and the measured 2212 composition upon extended anneals at 865 °C showed that considerably longer heat treatments were necessary for the sample to reach its equilibrium state.

Influence of Annealing Time on Microstructure of Ni-W Alloys

2013 ◽  
Vol 747-748 ◽  
pp. 613-618
Author(s):  
Qiao Zhang ◽  
Shu Hua Liang ◽  
Chen Zhang ◽  
Jun Tao Zou
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Grain Size ◽  
Grain Boundaries ◽  
Annealing Time ◽  
Single Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Average Grain Size ◽  
Scanning Electron

The as-cast Ni-W alloys with 15wt%W, 25wt%W and 30wt%W were annealed in hydrogen at 1100. The effect of the annealing time on the microstructure of Ni-W alloys was studied, and the phase constituents and microstructure of annealed Ni-W alloys were characterized by the X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that no any phase changed for Ni-15%W, Ni-25%W and Ni-30%W alloys annealed for 60 min, 90 min and 150 min, which were still consisted of single-phase Ni (W) solid solution. However, microstructure had a significant change after annealing. With increase of annealing time, the microstructure of Ni-15%W alloy became more uniform after annealing for 90 min, and the average grain size was 95μm, whereas the grain size of Ni-15%W alloy increased significantly after annealing for 150 min. For Ni-25%W and Ni-30%W, there was no obvious change on the grain size with increase of annealing time, and the amount of oxides at grain boundaries gradually reduced. After annealing for 150 min, the impurities at grain boundaries almost disappeared. Subsequently, the annealing at 1100 for 150 min was beneficial for the desired microstructure of Ni-25%W and Ni-30%W alloys.

Crystallization of a SiO2-MgO-Al2O3-K2O-Fe2O3-F Glass

2007 ◽  
Vol 336-338 ◽  
pp. 1829-1832 ◽  
Author(s):  
Qing Bo Tian ◽  
Yue Wang ◽  
Xue Tao Yue ◽  
Yan Sheng Yin ◽  
Su Hua Fan
Keyword(s):  
Phase Separation ◽  
Electron Probe ◽  
X Ray Diffraction ◽  
Crystalline Phases ◽  
Present Glass ◽  
X Ray ◽  
Heat Treated ◽  
Mica Crystal ◽  
Step Heat Treatment ◽  
Scanning Electron

The phase-separation and the crystallization of SiO2-MgO-Al2O3-K2O-Fe2O3-F glass were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron probe of microanalyzers (EPMA). The results reveal that the varieties and the morphology of crystalline phases formed depend sensitively on the thermal treatment schedules. During the isothermal treatments, the crystalline phases of mica, mica and iron oxide (FeFeO4), and FeFeO4 as major crystals are precipitated in the glass samples heat-treated at 900, 1000 and 1050°C respectively. However, the two-step heat treatment beginning at 900°C for 1h and subsequently followed at 1050°C for 1h leads to the precipitation of mica crystal and no any signs of FeFeO4 crystalline phase is observed. Also the morphology of sample is different from that of the isothermally treated glass at 1050°C, but is similar from that of sample at 900°C. A “worm”-shaped phase-separation is observed in the sample heated at 800°C for 0.5h, which exhibits different morphology from that of droplet- or globule-shape conventionally discerned. EPMA results show that the incorporation of Fe2O3 accelerates accumulation of fluorine element, promoting the phase-separation and the crystallization of the present glass.

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