scholarly journals The Application of X-rays for an Electrodeposition of Composite Coatings with Modified Structures and Properties

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4913
Author(s):  
Natalia Valko ◽  
Wiktoria Evstigneeva ◽  
Victor Anishchik ◽  
Vitalii Bondariev ◽  
Pawel Okal ◽  
...  
Keyword(s):  
Composite Coatings ◽  
Experimental Studies ◽  
Sio2 Nanoparticles ◽  
Electrolytic Cell ◽  
Electrolytic Deposition ◽  
X Rays ◽  
Mass Rate ◽  
Orienting Effect ◽  
Dispersing Ability ◽  
Electroplating Process

Experimental studies of the effect of X-rays on the process of electrolytic deposition of composite coatings are reviewed in this paper. Particular emphasis will be on the applications of X-rays for both the modification of a structure and the mechanical characteristics of galvanic coatings. In particular, this research investigates the Co/SiO2 coatings deposited from aqueous solutions under the effect of X-rays. The results of extensive investigations into the dispersing ability of electrolytes with SiO2 nanoparticles and a mass rate of composite coatings Co/SiO2 indicates that the method of electroplating under the effect of X-rays during the process results in the intensification of diffusion in the electrolyte volume and creates dense, uniform coatings. This research demonstrates that exposure of an electrolytic cell to X-rays during the electroplating process of Co/SiO2 results in an orienting effect on the formation of crystal grains and allows for the creation of dense, morphology uniform coatings with increased hardness and improved adhesion.

scholarly journals A comprehensive Monte Carlo study to design a novel multi-nanoparticle loaded nanocomposites for augmentation of attenuation coefficient in the energy range of diagnostic X-rays

2021 ◽  
Vol 27 (4) ◽  
pp. 279-289
Author(s):  
Elahe Sayyadi ◽  
Asghar Mesbahi ◽  
Reza Eghdam Zamiri ◽  
Farshad Seyyed Nejad
Keyword(s):  
Monte Carlo ◽  
Energy Range ◽  
Radiation Protection ◽  
Experimental Studies ◽  
Rubber Matrix ◽  
Photon Flux ◽  
Monte Carlo Code ◽  
X Rays ◽  
Wide Range ◽  
Shielding Properties

Abstract Introduction: The present study aimed to investigate the radiation protection properties of silicon-based composites doped with nano-sized Bi2O3, PbO, Sm2O3, Gd2O3, WO3, and IrO2 particles. Radiation shielding properties of Sm2O3 and IrO2 nanoparticles were investigated for the first time in the current study. Material and methods: The MCNPX (2.7.0) Monte Carlo code was utilized to calculate the linear attenuation coefficients of single and multi-nano structured composites over the X-ray energy range of 10–140 keV. Homogenous distribution of spherical nanoparticles with a diameter of 100 nm in a silicon rubber matrix was simulated. The narrow beam geometry was used to calculate the photon flux after attenuation by designed nanocomposites. Results: Based on results obtained for single nanoparticle composites, three combinations of different nano-sized fillers Sm2O3+WO3+Bi2O3, Gd2O3+WO3+Bi2O3, and Sm2O3+WO3+PbO were selected, and their shielding properties were estimated. In the energy range of 20-60 keV Sm2O3 and Gd2O3 nanoparticles, in 70-100 keV energy range WO3 and for photons energy higher than 90 keV, PbO and Bi2O3 nanoparticles showed higher attenuation. Despite its higher density, IrO2 had lower attenuation compared to other nanocomposites. The results showed that the nanocomposite containing Sm2O3, WO3, and Bi2O3 nanoparticles provided better shielding among the studied samples. Conclusions: All studied multi-nanoparticle nanocomposites provided optimum shielding properties and almost 8% higher attenuation relative to single nano-based composites over a wide range of photon energy used in diagnostic radiology. Application of these new composites is recommended in radiation protection. Further experimental studies are suggested to validate our findings.

scholarly journals Enhanced Mechanical and Tribological Capabilities of a Silicon Aluminum Alloy with an Electroplated Ni–Co–P/Si3N4 Composite Coating

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 120
Author(s):  
Zhijie Li ◽  
Fei Ma ◽  
Dongshan Li ◽  
Shanhong Wan ◽  
Gewen Yi ◽  
...  
Keyword(s):  
Abrasive Wear ◽  
Composite Coating ◽  
Composite Coatings ◽  
Engine Oil ◽  
Si Substrate ◽  
Wear Performance ◽  
Cobalt Layer ◽  
Hard Chrome ◽  
Electroplating Process ◽  
Hardness Values

Ni–Co–P/Si3N4 composite coatings were fabricated over an aluminum–silicon (Al–Si) substrate using a pulse-current electroplating process, in which the rapid deposition of an intermediate nickel–cobalt layer was used to improve coating adhesion. The microstructure, mechanical, and tribological behaviors of the electroplated Ni–Co–P/Si3N4 composite coating were characterized and evaluated. The results revealed that the electroplated Ni–Co–P/Si3N4 composite coating primarily consisted of highly crystalline Ni–Co sosoloid and P, and a volumetric concentration of 7.65% Si3N4. The electroplated Ni–Co–P/Si3N4 composite coating exhibited hardness values almost two times higher than the uncoated Al–Si substrate, which was comparable to hard chrome coatings. Under lubricated and dry sliding conditions, the electroplated Ni–Co–P/Si3N4 composite coating showed excellent anti-wear performance. Whether dry or lubricated with PAO and engine oil, the composite coating showed minimum abrasive wear compared to the severe adhesive wear and abrasive wear observed in the Al–Si substrate.

Improved Corrosion Resistance and Increased Hardness of Copper Substrates from Cu-Ni/Ni-P Composite Coatings

MRS Advances ◽  
2020 ◽  
Vol 5 (40-41) ◽  
pp. 2129-2137 ◽  
Author(s):  
Wenwen Dou ◽  
Wen Li ◽  
Yuchen Cai ◽  
Mengyao Dong ◽  
Xiaojing Wang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Composite Coatings ◽  
Copper Substrate ◽  
Electrolytic Deposition ◽  
Deposition Method ◽  
Nacl Solution ◽  
Current Densities ◽  
Superior Corrosion Resistance ◽  
Deposition Conditions

ABSTRACTTo improve the corrosion resistance and to increase the hardness of copper substrate in marine environment, the Cu-Ni/Ni-P composite coatings were prepared on the copper substrate using the galvanostatic electrolytic deposition method. The deposition current densities were explored to find the optimized deposition conditions for forming the composite coatings. Corrosion resistance properties were analyzed using the polarization curves and electrochemical impedance spectroscopy (EIS). Considering the corrosion resistance and hardness, the −20 mA/cm2 was selected to deposit Cu-Ni coatings on copper substrate and the −30 mA/cm2 was selected to deposit Ni-P coating on the Cu-Ni layer. The Cu-Ni/Ni-P composite coatings not only exhibited superior corrosion resistance compared to single Cu-Ni coating in 3.5 wt.% NaCl solution, but also showed much better mechanical properties than single Cu-Ni coating.

THE IMMEDIATE EFFECTS OF SEVERE LOCAL X IRRADIATION ON THE LIVER OF THE HAMSTER

1952 ◽  
Vol 30 (6) ◽  
pp. 571-577
Author(s):  
Katherine E. Livingstone ◽  
David J. McCallion
Keyword(s):  
Experimental Studies ◽  
Liver Parenchyma ◽  
Liver Cells ◽  
The Body ◽  
Field Size ◽  
Cyclic Variation ◽  
X Rays ◽  
X Irradiation ◽  
Parenchymal Cells ◽  
Cyclic Fluctuation

Opinions regarding the radiosensitivity of the liver, based on clinical and experimental studies, differ widely. No comprehensive study of the immediate effects of severe local X irradiation upon the cytology of the liver parenchyma has been previously undertaken. In the present investigation cytological studies were made upon the livers of hamsters at 4-hr. intervals over a 24-hr. period. It was demonstrated that the amounts of cytoplasmic basophilia, glycogen, and sudanophilic fat show a cyclic variation over the 24-hr. period studied. Adult hamsters were exposed to X rays at the rate of 495 r. per minute with a total dosage of 2000 r. The field size over the liver was 4 cm. by 2 cm. with the rest of the body protected by a lead shield. Following irradiation the animals were sacrificed, two at a time, at 4 hr. intervals over a 24-hr. period. The amounts of basophilic material in the cytoplasm of the parenchymal cells of the liver were considerably decreased at 8 hr. and at 16 hr. after irradiation. At other times the cytoplasmic basophilia of the irradiated liver cells was approximately as dense as that of the control animals. The density of cytoplasmic basophilia showed a cyclic variation approximating that of the controls. The amount of glycogen in the irradiated livers was very much decreased, but still showed a cyclic fluctuation. There was a striking decrease in the amount of sudanophilic fat in the liver cells following irradiation. The results indicate that severe local X irradiation of the liver of the hamster has immediate effects directly upon that organ, resulting in a disturbance of its normal physiological activities.

scholarly journals Evaluation of environmental friendly Ag-PTFE composite coating for use in threaded compression fittings

2017 ◽  
Vol 232 (5) ◽  
pp. 503-512 ◽  
Author(s):  
Raymond Sieh ◽  
Huirong Le
Keyword(s):  
Stainless Steel ◽  
Solid Lubricant ◽  
Composite Coatings ◽  
Operating Conditions ◽  
Vacuum System ◽  
Environmental Friendly ◽  
Potential Risks ◽  
Fluid Transfer ◽  
Electroplating Process ◽  
Torque Angle

Threaded tubular fittings are used in a wide variety of industries for critical applications involving fluid transfer in a pressurised or vacuum system. These fittings are made of corrosion resistant metals such as stainless steel which are desirable in corrosive operating conditions; however, stainless steel is prone to galling which can cause threads to seize, resulting in loss of productivity. To prevent this, threads are electroplated using silver (Ag) coatings which prevent galling and serve as a solid lubricant during the connection make-up process. The Ag cyanide electroplating process currently used in industry is both hazardous to human health and its wastes are detrimental to the environment. The objective of this work is to evaluate environmental friendly self-lubricating Ag and Ag-polytetrafluoroethylene composite coatings using a non-cyanide electroplating process against the commercially available cyanide Ag coating through the analysis of torque-angle signatures and the torque-angle slope which characterises the make-up process. Results from the experiments suggest that the non-cyanide Ag-polytetrafluoroethylene coating is a potentially viable replacement option. Investigation and analysis of the coating performance have also highlighted potential risks of failure through poor lubrication during the make-up process and suggestions for improving the make-up process.

Study on Electroplated Diamond Wire Saw Development and Wire Saw Wear Analysis

2009 ◽  
Vol 416 ◽  
pp. 311-315 ◽  
Author(s):  
Pei Qi Ge ◽  
Yu Fei Gao ◽  
Shao Jie Li ◽  
Zhi Jian Hou
Keyword(s):  
Current Density ◽  
High Performance ◽  
Experimental Studies ◽  
Cathode Current Density ◽  
Diamond Wire ◽  
Wire Saw ◽  
Diamond Wire Saw ◽  
Cathode Current ◽  
The Wire ◽  
Electroplating Process

Development of high performance diamond impregnated wire is the key of application for fixed-abrasive wire sawing technology. In this paper, some experimental studies were done for development of electroplated diamond wire saw by employing the bright nickel bath. The wire saw electroplating process was developed, the effects of cathode current density and time at tack-on stage on diamond grits density and adhesion between saw matrix and plating coating were discussed. The wire saw cutting experiments were carried out for analysis the used wire wear using the scanning electron microscope (SEM). The experimental results show the optimum tack-on current density to obtain the wire saw with good abrasive distribution and adhesion is 1.5~2.0A/dm2, and the time of pre-plating, tack-on and buildup is 6, 8~10 and 18min in turn. Diamond wire saw wear includes coating wear and grain-abrasion, and the primary wear form is grits pulled-out.

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