A miniature metal–ceramic x-ray source for spacecraft instrumentation

1998 ◽  
Vol 69 (4) ◽  
pp. 1893-1897 ◽  
Author(s):  
L. N. Koppel ◽  
J. R. Marshall
Keyword(s):  
X Ray ◽  
Metal Ceramic ◽  
Spacecraft Instrumentation

Fe–Cr/Al2O3 metal-ceramic composites: Nature and size of the metal particles formed during hydrogen reduction

1994 ◽  
Vol 9 (1) ◽  
pp. 229-235 ◽  
Author(s):  
Ch. Laurent ◽  
J.J. Demai ◽  
A. Rousset ◽  
K.R. Kannan ◽  
C.N.R. Rao
Keyword(s):  
Hydrogen Reduction ◽  
Ceramic Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Total Reduction ◽  
Transmission Electron ◽  
Combined Use ◽  
Metal Ceramic ◽  
Different Temperatures ◽  
Metallic Species

Fe-Cr/Al2O3 metal-ceramic composites prepared by hydrogen reduction at different temperatures and for different periods have been investigated by a combined use of Mössbauer spectroscopy, x-ray diffraction, transmission electron microscopy, and energy-dispersive x-ray spectroscopy in order to obtain information on the nature of the metallic species formed. Total reduction of Fe3+ does not occur by increasing the reduction time at 1320 K from 1 to 30 h, and the amount of superparamagnetic metallic species is essentially constant (about 10%). Temperatures higher than 1470 K are needed to achieve nearly total reduction of substitutional Fe3+. Interestingly, iron favors the reduction of chromium. The composition of the Fe-Cr particles is strongly dependent on their size, the Cr content being higher in particles smaller than 10 nm.

scholarly journals Laser assisted selective chemical metalization of Al2O3 films

2005 ◽  
Vol 3 (4) ◽  
pp. 668-673
Author(s):  
Emil Krumov ◽  
Dimitar Popov ◽  
Nikolay Starbov
Keyword(s):  
Thermal Evaporation ◽  
Chemical Deposition ◽  
Ceramic Surface ◽  
Ceramic System ◽  
X Ray ◽  
Deposited Metal ◽  
Metal Ceramic ◽  
Selective Chemical ◽  
Processing Steps ◽  
Al2o3 Films

AbstractThick aluminum oxide films are prepared on Al plates by anodizing. On the ceramic surface thus obtained a very thin Ag film is deposited via vacuum thermal evaporation. The Ag/Al2O3/Al samples prepared are irradiated by Nd:YAG laser through a suitable metal mask in order to remove the top metal film in the exposed areas. Thus, a negative silver image of the copied mask is obtained. Further, the samples are processed in Ni electroless chemical bath activated by the rest of silver. All processing steps are studied by scanning electron microscopy (SEM). EDS X-ray mapping is applied to study the final distribution of Al and Ni in the processed areas. In addition, the DC conductivity of the fabricated Ni wires obtained is measured. The proposed new method for selective chemical deposition of electroconductive Ni onto laser microstructured Ag/Al2O3/Al samples is simple, versatile and not restricted to the metal/ceramic system studied as well as to the electroless deposited metal.

Investigation on emission characteristics of metal-ceramic cathode applied to industrial X-ray diode

2016 ◽  
Vol 87 (6) ◽  
pp. 063301 ◽  
Author(s):  
Ma Xun ◽  
Yuan Jianqiang ◽  
Liu Hongwei ◽  
Li Hongtao ◽  
Wang Lingyun ◽  
...  
Keyword(s):  
Emission Characteristics ◽  
X Ray ◽  
Metal Ceramic

Microstructure of Bonding Interface in Explosively Welded Metal/Ceramic Clad

2010 ◽  
Vol 638-642 ◽  
pp. 3775-3780 ◽  
Author(s):  
Seiichiro Ii ◽  
Chihiro Iwamoto ◽  
Shinobu Satonaka ◽  
Kazuyuki Hokamoto ◽  
Masahiro Fujita
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silicon Nitride ◽  
Electron Diffraction ◽  
Electron Diffraction Pattern ◽  
Explosive Welding ◽  
Bonding Interface ◽  
X Ray ◽  
Transmission Electron ◽  
Metal Ceramic

Bonding interface in aluminum (Al) and silicon nitride (Si3N4) clad fabricated by explosive welding has been investigated by transmission electron microscopy (TEM). The nanocrystalline region was clearly observed at the interface between Al and Si3N4. Electron diffraction pattern and energy dispersive X-ray spectroscopy (EDS) measurements across the interface revealed that this nanocrystalline region consist of the only aluminum.

scholarly journals Synthesis and some Features of Three-Phases Polymer/Metal/Ceramic Multilayers Nanocomposite

2020 ◽  
Vol 33 (4) ◽  
pp. 10
Author(s):  
Raghad S. Abbas Al-Khafaji
Keyword(s):  
Cadmium Oxide ◽  
Laser Deposition ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Ceramic ◽  
Polymer Metal ◽  
High Kinetic Energy ◽  
New Compounds ◽  
Layer Development

      Layer by layer development two features of pulsed laser deposition PLD, with a high kinetic energy and sharp instantaneous deposition rating. Layered films of polymer/metal/ceramic nanocomposites consisting of polystyrene PS(as substrate) , tin Sn and cadmium oxide CdO were deposited by PLD. Structure for layered samples were measured  by XRD X ray diffraction, there were appearance of peaks  which reflected  to formation of new compounds result of  reaction between layers. Particles size  was calculated using two methods and it give nanoscale. Microstrain was also calculated  and exhibited  high value (0.01) for sample p/m.  

scholarly journals Chemical and Wetting Analysis of the Ni-Ti Coating on SiC Improved by a 2-Step Coating-Sintering Process

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5235
Author(s):  
Yang Liu ◽  
Ying-Xin Wang ◽  
Qiang Yang ◽  
Fu Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Control Groups ◽  
X Ray ◽  
Surface Energies ◽  
Metal Ceramic ◽  
Sintering Conditions ◽  
Scanning Electron

A two-stepped coating-sintering process to prepare the qualified Ni–Ti transition applied in metal-ceramic bonding proved to be effective to improve the wetting abilities. The method was introduced in detail and compared with 2 control groups. To analyze the benefits, the morphology and composition were captured by field emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The comparisons of different coating depths and different sintering conditions were also recorded and analyzed. The influence of the EDS detecting depth was a concern in the discussions. Finally, the contact angle tests and surface energies were also estimated to verify the reliability of the transition layer. The results indicated that the coating-sintering process combined with protective sintering was preferred and necessary to increase the activeness.

High Temperature Chemical Interaction Between SSiC Substrates and Ag-Cu Based Liquid Alloys in Vacuo

2006 ◽  
Vol 509 ◽  
pp. 111-116 ◽  
Author(s):  
Jorge López-Cuevas ◽  
Juan Carlos Rendón-Angeles ◽  
J.L. Rodríguez-Galicia ◽  
M. Herrera-Trejo ◽  
J. Méndez-Nonell
Keyword(s):  
Electron Microscopy ◽  
Chemical Interaction ◽  
Silica Film ◽  
Liquid Alloys ◽  
Ceramic Surface ◽  
X Ray Diffraction ◽  
Metal Interface ◽  
X Ray ◽  
Metal Ceramic ◽  
Scanning Electron

The interfaces formed at 850 °C under vacuum between polished or oxidized substrates of pressureless sintered α-SiC (SSiC) and Cusil, Cusil-ABA and Incusil-ABA brazing alloys have been characterized by X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. No chemical interaction is observed for Cusil on both SSiC substrates. In contrast, the Ti contained in the Cusil-ABA and Incusil-ABA alloys promotes the occurrence of chemical reactions at the metal/ceramic interface with both SSiC substrates. The formation of TiC and Ti5Si3 is observed for Cusil-ABA and Incusil-ABA on untreated SSiC, following the sequence SiC → TiC → Ti5Si3 at the metal/ceramic interface. The formation of Ti5Si3 and Cu3Ti3O, following the sequence SiC → Ti5Si3 → Cu3Ti3O, is observed for both Ti-containing alloys on pre-oxidized SSiC. During the wetting experiments, Ti5Si3 and Cu3Ti3O detach from the ceramic surface, floating away from the ceramic/metal interface into the liquid alloy, where the latter phase partially dissolves. It is concluded that for both Ti-containing alloys in contact with pre-oxidized SSiC, the Ti remaining after the reaction with the silica film is insufficient to decrease the contact angle to the values observed for untreated SSiC or to produce a strong metal/ceramic joint.

Interface Phenomena of Co-Sintered Steel-Zirconia Laminates

2015 ◽  
Vol 825-826 ◽  
pp. 289-296 ◽  
Author(s):  
Anne Bergner ◽  
Tassilo Moritz ◽  
Alexander Michaelis
Keyword(s):  
Paper Industry ◽  
Tape Casting ◽  
Fluorescence Analysis ◽  
Surgical Instruments ◽  
Special Focus ◽  
Premature Failure ◽  
X Ray ◽  
Bipolar Scissors ◽  
Composite Formation ◽  
Metal Ceramic

The composite formation of steel and ceramics is especially for medical applications of great interest. By use of the multicomponent tape casting metal-ceramic composite components like bipolar scissors and other surgical instruments can be produced. A coating technology that comes from the paper industry, allows to apply a very thin insulating layer of a few microns between the electrodes consisting of stainless steel. Until now bipolar surgical instruments are produced by mechanical joining of steel and ceramic parts or by spraying a ceramic layer on the steel instruments. This joining steps can lead to stresses in the sensitive ceramic material and leave fine interstices or pores that are not only avoidable with a force and / or tight fit. Both factors are reasons for premature failure of the instrument, even if the materials are not yet at the limits of their resistance. Through the joint shaping by the tape casting and subsequent co-sintering of both materials, a material bond is achieved in addition to the previously existing mechanisms of force and form fit. This optimizes the composite properties and increases the usage time of metal-ceramic layered composites. Special focus is given to the formation of the interface and the associated changes in properties of the individual components of the laminate. These investigantions illustrate the influence of co-manufacturing on the texture of the laminate materials and the formed interface between them. By x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), x-ray fluorescence analysis (RFA) and thermodynamic calculations (FactSage) of the material bond at the metal-ceramic interface is investigated. In various application areas where steel and zirconia should occur as integral partners, this material combination may be established.

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