Electron Microscopy and Raman Spectroscopy Study of Pu-Bearing LaBS Glasses

2012 ◽  
Vol 1444 ◽  
Author(s):  
S.V. Stefanovsky ◽  
A.A. Shiryaev ◽  
I.E. Vlasova ◽  
V.O. Yapaskurt ◽  
J.C. Marra
Keyword(s):  
Electron Microscopy ◽  
Solution Phase ◽  
Solid Solution Phase ◽  
Vitreous Phase ◽  
Spectroscopy Study ◽  
Near Surface ◽  
X Ray ◽  
A Minor ◽  
Elemental Maps ◽  
Minor Concentration

ABSTRACTTwo LaBS glasses containing 9.5 wt.% (#1) and 5.0 wt.% PuO2 (#2) were prepared by melting in Pt ampoules at 1500 C and examined by scanning electron microscopy with energy dispersive X-ray spectroscopy. The bulk of sample #1, both as-prepared and stored for 3 yrs, was amorphous with homogeneous PuO2 distribution. Sample #2, especially after storage for 2-3 yrs, was partly devitrified primarily in the near-surface area. As followed from X-ray elemental maps, the vitreous phase was enriched with Al and Si whereas larger elongated and smaller dendrite crystals strongly enriched with rare earths (La, Nd, Gd) and Si and minor amounts of Hf may be attributed to britholite. A minor concentration of Pu was also observed in this phase. Moreover, relatively minor amounts of white regular crystals with high PuO2 and lower HfO2 contents were observed in the samples and are probably associated with PuO2 and a PuO2-HfO2 cubic solid solution phase. Nevertheless, even in devitrified areas of the samples, the majority of the Pu remained in the vitreous phase where it was homogeneously distributed.

The Structure and Thermal Properties of ZrAlYN Films Deposited by Magnetron Sputtering

2014 ◽  
Vol 488-489 ◽  
pp. 9-13
Author(s):  
Guang Xian ◽  
Hai Bo Zhao ◽  
Hong Yuan Fan ◽  
Hao Du
Keyword(s):  
Electron Microscopy ◽  
Thermal Properties ◽  
Magnetron Sputtering ◽  
Oxidation Resistance ◽  
Solution Phase ◽  
Solid Solution Phase ◽  
Flow Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

ZrAlYN films were prepared by magnetron sputtering at various N2/Ar flow ratio. The structure, composition and thermal properties were characterized by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectrum. The results show that the deposited ZrAlN and ZrAlYN films possessed a single NaCl-type solid solution phase. The ZrAlN film was (200) strongly predominated. The (111) peak was prominently increased in ZrAlYN films and thus the preferred orientation changed to (111) and (200) co-predomination. The crystallinity of ZrAlYN films was gradually degraded with enhanced N2/Ar flow ratio. Both ZrAlN and ZrAlYN films were exhibited a featureless fracture microstructure. The thickness of ZrAlYN films was consistently reduced due to more nitride produced on the surface of targets at higher N2/Ar flow ratio. The ZrAlYN films deposited at 1:5 N2/Ar flow ratio was proved to be the best oxidation resistance under annealing at 1000°C for 2h in air. As N2/Ar flow ratio increased, the oxidation resistance of films was inversely deteriorated due to the decreased yttrium content in films.

Nucleation of (Mo) Precipitates on Dislocations During Annealing of a Mo-rich Mo5SiB2 Phase

2004 ◽  
Vol 842 ◽  
Author(s):  
Nobuaki Sekido ◽  
Ridwan Sakidja ◽  
John H. Perepezko
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Solution Phase ◽  
Solid Solution Phase ◽  
Precipitation Behavior ◽  
Cast State ◽  
X Ray ◽  
Transmission Electron ◽  
Nucleation Sites ◽  
Means Of Transmission

ABSTRACTUpon annealing an as-cast Mo-10Si-20B alloy at high temperatures, a Mo solid solution phase precipitates within a supersaturated Mo5SiB2 phase. The precipitation behavior of the Mo solid solution was investigated by means of transmission electron microscopy and X-ray diffractometry. It is found that the Mo5SiB2 phase in a Mo-10Si-20B alloy contains a significant amount of structural vacancies in the as-cast state. The excess vacancies are removed to form dislocations during annealing, which provides the heterogeneous nucleation sites for the (Mo) precipitates.

Heat Treatment and Oxidation Characteristics of Nb-20Mo-15Si-5B-20(Cr,Ti) Alloys from 700 to 1400°C

2010 ◽  
Vol 638-642 ◽  
pp. 2351-2356 ◽  
Author(s):  
Sylvia Natividad ◽  
Arianna Acosta ◽  
Krista Amato ◽  
Julieta Ventura ◽  
Benedict Protillo ◽  
...  
Keyword(s):  
Unit Area ◽  
Annealing Treatment ◽  
Microstructural Characterization ◽  
Solution Phase ◽  
Solid Solution Phase ◽  
Ti Alloy ◽  
X Ray ◽  
Ti Alloys ◽  
Higher Temperature ◽  
Oxidation In Air

Nb-20Mo-15Si-5B-20(Cr,Ti) alloys have been subjected to annealing treatment for 2 hours in a range of temperatures from 700 to 1400oC and quenched in water to perform the microstructural characterization for these two new alloys. As cast structure consists of a solid solution phase, , and silicides (Nb5Si3) in both alloys but Cr alloy also contains NbCr2 and Nb3Si phases. Heating to higher temperature introduces Ti silicides in the microstructure for Ti alloy. The oxidation in air has been conducted on these alloys in the same temperature range for 24 hours. Weight gain per unit area as a function of temperature provides the oxidation curves while characterization techniques using SEM, EDS on SEM, x-ray mapping, and XRD has yielded the analyses of the oxide scale. The scale consists of various oxides of Nb, Mo, Cr, Si, and Ti. Cr alloy appears to offer higher oxidation resistance in the selected range of oxidation temperatures.

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.

scholarly journals Effect of CNT Contents on the Microstructure and Properties of CNT/TiMg Composites

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1620
Author(s):  
Xiaomin Yuan ◽  
Haonan Zhu ◽  
Huiling Ji ◽  
Yiwei Zhang
Keyword(s):  
Cross Section ◽  
Optical Microscope ◽  
Solution Phase ◽  
Solid Solution Phase ◽  
Wet Milling ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microstructure Observation ◽  
The Matrix ◽  
Scanning Electron

Carbon nanotubes (CNTs), dispersed in absolute ethanol, were evenly mixed into Ti/MgH2 powders by wet milling. Then, we applied the vacuum hot-pressed sinteringmethod to the CNTs/TiMg composite materials. An optical microscope (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) and a field emission scanning electron microscope (FESEM) were used for the microstructure observation and phase analysis of samples. The mechanical properties were measured via the micro-vickers hardness. The results show that the main phases in the composites were Ti, Mg and C. Meanwhile, a small amount of Ti-Mg solid solution phase was also found. The cross-section morphology of the composites shows that the melted magnesium fills the grain interface during extrusion and that the composites have a better compactness.The microstructures of the composites have been greatly refined as the CNT contents increased. The structure of the composites was further refined when 0.5 wt.% CNTs were added. The fracture surface is obviously a ductile fracture. The microhardness increases obviously with the CNT content increasing. When the content of the CNTs is 1.0 wt.%, the microhardness of the composites reaches 232 HV, which is 24% higher than that of the matrix.

scholarly journals Sb distribution in the phases of SiO2 saturated Sb-Fe-O-SiO2-CaO system in air

2020 ◽  
pp. 30-30
Author(s):  
Z.T. Zhang ◽  
H.P. Nie ◽  
K. Yan
Keyword(s):  
Solid Solution ◽  
Mass Fraction ◽  
Solution Phase ◽  
Smelting Process ◽  
Solid Solution Phase ◽  
Antimony Content ◽  
X Ray ◽  
Yield Rate ◽  
Temperature Experiment ◽  
First Time

Sb distribution in the phases of SiO2 saturated Sb-Fe-O-SiO2-CaO system has been determined for the first time through high-temperature experiment and quenching techniques, followed by Electron probe X-ray microanalysis(EPMA) in air(Ptot= 1 atm, PO2= 0.21 atm). The phases were quantified in the temperature range of 900?C-1200?C and the effects of Fe/SiO2(mass fraction) and CaO/SiO2(mass fraction) on Sb2O3 content in the Sb-Fe-O-SiO2-CaO system were investigated at 1200?C. The results indicate that the Sb-containing phase primarily existed in the solid solution phase at 1200?C. With the increase of temperature from 1100?C to 1200?C, the Sb2O3 content in the solid solution phase increased drastically from 7.52 wt% to 17.36 wt%. Lowering the values of CaO/SiO2 and Fe/SiO2 in the smelting process effectively reduced Sb2O3 content in the slag. The verification experiment results suggest that the antimony content in slag was 0.57 wt%, the crude antimony yield rate was lower than 4%,and the crude antimony grade was beyond 94 wt%, which can achieve the reduction of antimony content in the slag.

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