Developing glass composition for glass coated In and Sn cast microwires

2021 ◽  
pp. 117-120
Author(s):  
O. V. Vasilieva ◽  
B. V. Farmakovsky ◽  
M. V. Khromenkov
Keyword(s):  
Research And Development ◽  
Current Density ◽  
Glass Composition ◽  
Stable Process ◽  
High Melting ◽  
Optimal Composition ◽  
Small Base ◽  
Melting Current

The paper presents the results of research and development of glasses for insulation of cast microwires of the PbO - SiO2 - Na2O - InO2 - SnO2 system. The optimal composition has been determined, which makes it possible to establish a stable process of casting microwires from indium and tin with a length of more than 1000 meters. It is shown that from such microwires it is possible that small base fusible fuses with a high melting current density could be manufactured. 

Metal Transfer in Double-Electrode Gas Metal Arc Welding

2007 ◽  
Vol 129 (6) ◽  
pp. 991-999 ◽  
Author(s):  
Kehai Li ◽  
YuMing Zhang
Keyword(s):  
Base Metal ◽  
Arc Welding ◽  
High Speed ◽  
Gas Metal Arc Welding ◽  
High Melting ◽  
High Productivity ◽  
Spray Transfer ◽  
Metal Arc Welding ◽  
Double Electrode ◽  
Melting Current

Gas metal arc welding (GMAW) is the most widely used process for metal joining because of its high productivity and good quality, but analysis shows that the fundamental characteristic restricts conventional GMAW from further increasing the welding productivity. A novel GMAW process, refereed to as double-electrode GMAW or DE-GMAW, thus has been developed to make it possible to increase the melting current while the base metal current can still be controlled at a desired level. This fundamental change provides an effective method to allow manufacturers to use high melting currents to achieve high melting speed and low base metal heat input. A series of experiments have been conducted to uncover the basic characteristics of this novel process. Results obtained from analyses of high-speed image sequences and recorded current signals suggest that DE-GMAW can lower the critical current for achieving the desired spray transfer, shift the droplet trajectory, reduce the diameter of the droplet, and increase the speed and (generation) rate of the droplets.

Structure and current melting densities of microwires in glass insulation made of copper and resistive alloy based on nickel

2019 ◽  
pp. 54-58
Author(s):  
B. V. Farmakovsky
Keyword(s):  
Current Density ◽  
High Melting ◽  
Metal Core ◽  
Electric Circuits ◽  
Glass Insulation

The paper studies the structure of cast microwires in glass insulation, obtained at the current density, which leads to melting of the metal core. High melting currents values allow us to recommend cast microwires as low-base fuses against current overloads in electric circuits. 

scholarly journals Sharp peak of the critical current density in BaFe2−xNixAs2 at optimal composition

2020 ◽  
Vol 101 (23) ◽  
Author(s):  
Derrick Van Gennep ◽  
Abdelwahab Hassan ◽  
Huiqian Luo ◽  
Mahmoud Abdel-Hafiez
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Sharp Peak ◽  
Optimal Composition

scholarly journals MULTI-RESPONSE OPTIMISATION OF ELECTRODEPOSITION OF NANO-CRYSTALLINE COMPOSITE COATINGS Cr-Cr3P IN STATU NASCENDI FROM TRIVALENT CHROMIUM-BATHS

2021 ◽  
Vol 64 (3) ◽  
pp. 73-81
Author(s):  
Evgeny G. Vinokurov ◽  
Tatiana F. Burukhina ◽  
Ekaterina Yu. Napedenina
Keyword(s):  
Chemical Composition ◽  
Experimental Design ◽  
Current Efficiency ◽  
Current Density ◽  
Phosphorus Content ◽  
Composite Coatings ◽  
Optimization Techniques ◽  
Optimal Composition ◽  
Electrodeposition Process ◽  
X Ray

In this paper the effect of parameters such as current density, temperature, electrolytic bath pH and concentration of chromium sulfate and sodium hypophosphite on the electrodeposition process of the Cr-P alloys was investigated. Chemical composition of the coatings was evaluated by scanning electron microscopy and X-ray diffraction. Experimental design 25-1 central composite design was used to evaluate the chemical composition of alloys, current efficiency and the appearance of coatings as well as to optimize the electrodeposition process of the alloy using Response Surface Methodology associated with experimental design. The Harrington desirability function was applied for optimization. The optimal composition of bath (in g/l) and electrolysis conditions are proposed: Cr2(SO4)3·6H2O – 285, Al2(SO4)3·12H2O – 120, Na2SO4 – 50, NaH2PO2·H2O – 20, CO(NH2)2 – 70, рН – 1.3, temperature – 35 ºС, current density – 46 А/dm2. An acceptable current efficiency 13-14 % was observed for an alloy obtained under optimal conditions of 46 A/dm2, 35 °C and pH 1.3 from an electrolyte of optimal composition. Under these conditions, the coating contained 16 wt.% phosphorus. The alloys were X-ray amorphous at a phosphorus content of about 6 wt.%. When the phosphorus content was 16 wt.% the alloys became nanocrystalline and the chromium phosphide – Cr3P phase was released, which can be seen from the peaks on X-ray diffractograms. This indicates the formation of Cr-Cr3P nanocrystalline composite coatings under nucleation conditions (in Statu Nascendi). Therefore, the results of this work show the importance of using optimization techniques to obtain metallic coatings with controlled properties for different types of applications.

Activated Prominences; Mechanisms for Activation and Eruption

1979 ◽  
Vol 44 ◽  
pp. 307-313
Author(s):  
D.S. Spicer
Keyword(s):  
Pressure Gradient ◽  
Density Gradient ◽  
Current Density ◽  
Convective Instability ◽  
Tearing Mode ◽  
Magnetic Shear ◽  
Long Wavelength ◽  
Ideal Mhd ◽  
Gradient Change ◽  
Accelerated Particles

A possible relationship between the hot prominence transition sheath, increased internal turbulent and/or helical motion prior to prominence eruption and the prominence eruption (“disparition brusque”) is discussed. The associated darkening of the filament or brightening of the prominence is interpreted as a change in the prominence’s internal pressure gradient which, if of the correct sign, can lead to short wavelength turbulent convection within the prominence. Associated with such a pressure gradient change may be the alteration of the current density gradient within the prominence. Such a change in the current density gradient may also be due to the relative motion of the neighbouring plages thereby increasing the magnetic shear within the prominence, i.e., steepening the current density gradient. Depending on the magnitude of the current density gradient, i.e., magnetic shear, disruption of the prominence can occur by either a long wavelength ideal MHD helical (“kink”) convective instability and/or a long wavelength resistive helical (“kink”) convective instability (tearing mode). The long wavelength ideal MHD helical instability will lead to helical rotation and thus unwinding due to diamagnetic effects and plasma ejections due to convection. The long wavelength resistive helical instability will lead to both unwinding and plasma ejections, but also to accelerated plasma flow, long wavelength magnetic field filamentation, accelerated particles and long wavelength heating internal to the prominence.

Microstructural characterization of YBa2Cu3O7-x thin films formed by metalorganic CVD

1991 ◽  
Vol 49 ◽  
pp. 1080-1081
Author(s):  
P. Lu ◽  
W. Huang ◽  
C.S. Chern ◽  
Y.Q. Li ◽  
J. Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Film Growth ◽  
Chemical Vapor ◽  
Microstructural Characterization ◽  
Ion Milling ◽  
Conventional Grinding

The YBa2Cu3O7-x thin films formed by metalorganic chemical vapor deposition(MOCVD) have been reported to have excellent superconducting properties including a sharp zero resistance transition temperature (Tc) of 89 K and a high critical current density of 2.3x106 A/cm2 or higher. The origin of the high critical current in the thin film compared to bulk materials is attributed to its structural properties such as orientation, grain boundaries and defects on the scale of the coherent length. In this report, we present microstructural aspects of the thin films deposited on the (100) LaAlO3 substrate, which process the highest critical current density.Details of the thin film growth process have been reported elsewhere. The thin films were examined in both planar and cross-section view by electron microscopy. TEM sample preparation was carried out using conventional grinding, dimpling and ion milling techniques. Special care was taken to avoid exposure of the thin films to water during the preparation processes.

A Tem Study of Slip Systems in MoSi2/WSi2 Alloys

1991 ◽  
Vol 49 ◽  
pp. 942-943
Author(s):  
Stuart A. Maloy
Keyword(s):  
Solid Solution ◽  
Solid Solution Hardening ◽  
Slip Systems ◽  
High Melting ◽  
Group 14 ◽  
Solution Hardening ◽  
Brittle To Ductile Transition ◽  
High Melting Temperature ◽  
Tetragonal Unit Cell ◽  
Structural Applications

MoSi2 has recently been investigated as a potential material for high temperature structural applications. It has excellent oxidation resistance up to 1700°C, a high melting temperature, 2030°C, and a brittle-to-ductile transition temperature at 900-1000°C. WSi2 is isomorphous with MoSi2 and has a body-centered tetragonal unit cell of the space group 14/mmm. The lattice parameters are a=3.20 Å and c=7.84 Å for MoSi2 and a=3.21 Å and c=7.88 Å for WSi2. Therefore, WSi2 was added to MoSi2 to improve its strength via solid solution hardening. The purpose of this study was to investigate the slip systems in polycrystalline MoSi2/WSi2 alloys.

Analytical electron microscopy of grain boundaries in Al-Cu metallizations

1992 ◽  
Vol 50 (2) ◽  
pp. 1684-1685
Author(s):  
J. R. Michael ◽  
A. D. Romig ◽  
D. R. Frear
Keyword(s):  
Electron Microscopy ◽  
Integrated Circuits ◽  
Failure Mode ◽  
Current Density ◽  
Thermal History ◽  
Analytical Electron Microscopy ◽  
Cu Metallization ◽  
Analytical Electron ◽  
Interconnect Lines

Al with additions of Cu is commonly used as the conductor metallizations for integrated circuits, the Cu being added since it improves resistance to electromigration failure. As linewidths decrease to submicrometer dimensions, the current density carried by the interconnect increases dramatically and the probability of electromigration failure increases. To increase the robustness of the interconnect lines to this failure mode, an understanding of the mechanism by which Cu improves resistance to electromigration is needed. A number of theories have been proposed to account for role of Cu on electromigration behavior and many of the theories are dependent of the elemental Cu distribution in the interconnect line. However, there is an incomplete understanding of the distribution of Cu within the Al interconnect as a function of thermal history. In order to understand the role of Cu in reducing electromigration failures better, it is important to characterize the Cu distribution within the microstructure of the Al-Cu metallization.

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