Effect of the duty cycle of pulsed current on nanocomposite layers formed by pulsed electrodeposition

Rare Metals ◽  
2010 ◽  
Vol 29 (2) ◽  
pp. 209-213 ◽  
Author(s):  
M. Aliofkhazraei ◽  
Sh. Ahangarani ◽  
A. Sabour Rouhaghdam
Keyword(s):  
Duty Cycle ◽  
Pulsed Current ◽  
Pulsed Electrodeposition

CORROSION AND WEAR PROPERTIES OF ELECTRODEPOSITED TERTIARY NANOCOMPOSITE Zn–Ni (ALUMINA–YITTRIA–GERAPHENE) COATING

2016 ◽  
Vol 24 (05) ◽  
pp. 1750066 ◽  
Author(s):  
HAMED RAHMANI ◽  
MAHMOOD ALIOFKHAZRAEI ◽  
ABDOSSALAM KARIMZADEH
Keyword(s):  
Duty Cycle ◽  
Zinc Sulphate ◽  
Pulse Current ◽  
Corrosion And Wear ◽  
Pulsed Current ◽  
Passive Current Density ◽  
Wear Properties ◽  
Nickel Zinc ◽  
Pulsed Electrodeposition ◽  
Passive Current

Nanocomposite Ni–Zn coatings containing 80 wt.% Al2O3, 5 wt.% Y2O3 and 15 wt.% graphene were fabricated by pulsed electrodeposition method in nickel–zinc sulphate-based electrolyte and effects of pulse current parameters on nickel and other element contents, microstructure, resistance to corrosion and tribological properties of the coatings were investigated. The pulsed current with duty cycle from 10% to 50% was applied to different samples and frequency changed gradually from 500 to 4000[Formula: see text]Hz in five steps during coating process. Increasing the duty cycle led to decrease of absorbed nanoparticles in the surface of the coatings from 4.4 vol% to 3.58 vol% The sample coated with 10% duty cycle had utmost alumina content in the coating surface, 3.5 vol% in first layer up to 4.4 vol% in fifth layer. The sample coated with 30% duty cycle had higher corrosion resistance with passive current density of 2.5[Formula: see text]mA/cm2. Furthermore, the results showed that by increasing the duty cycle, wear rate had been increased up to 1.3[Formula: see text][Formula: see text][Formula: see text]10[Formula: see text][Formula: see text]mm2/N[Formula: see text]m.

scholarly journals STUDY OF THE COBALT-MOLYBDENE ALLOY ELECTRODEPOSITION PROCESS IN STATIONARY AND PULSE ELECTROLYESIS

2020 ◽  
pp. 86-91
Author(s):  
V. T. Fomichev ◽  
A. V. Savchenko ◽  
G. P. Gubarevich
Keyword(s):  
Current Efficiency ◽  
Polarization Curve ◽  
Duty Cycle ◽  
Electrolyte Composition ◽  
Molybdenum Alloy ◽  
Pulsed Current ◽  
Electrodeposition Process ◽  
Alloy Electrodeposition ◽  
Curve Method

The polarization curve method was used to study the process of co-deposition of cobalt and molybdenum using a constant and pulsed current of different duty cycle. The effect of the electrolyte composition, the parameters of the pulsed current on the current efficiency and the composition of the cobalt-molybdenum alloy is shown.

Effect of duty cycle on NiMo alloys prepared by pulsed electrodeposition for hydrogen evolution reaction

2021 ◽  
pp. 163161
Author(s):  
Victoria Benavente Llorente ◽  
Liliana A. Diaz ◽  
Gabriela I. Lacconi ◽  
Graciela C. Abuin ◽  
Esteban A. Franceschini
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Duty Cycle ◽  
Pulsed Electrodeposition

Electromigration Characteristics Under High Frequency Pulsed Current Stressing

1991 ◽  
Vol 225 ◽  
Author(s):  
Thomas Kwok ◽  
R. Kaufman ◽  
B. Davari
Keyword(s):  
Current Density ◽  
Duty Cycle ◽  
High Frequency ◽  
Drastic Change ◽  
Density Model ◽  
Pulsed Current ◽  
Average Current Density ◽  
Remarkable Improvement ◽  
Current Stressing ◽  
Average Current

ABSTRACTElectromigration characteristics of Al lines under pulsed current stressing at frequencies 50–200 MHz were measured. Lifetime was found to depend explicitly on both current on-time and current off period. Lifetime increases with t-off as t50 ∝ (t-off)2.2 and decreases with t-on as t50 ∝ (t-on)−0.7. The data indicate no threshold frequency for drastic change in lifetime. Lifetime was also found to increase with duty cycle as t50 ∝ r−2.7, which is a remarkable improvement over an average current density model.

Study of Growth Process for Functionally Gradient Nanocomposite Coating Fabricated by Plasma Electrolytic Carburizing

2012 ◽  
Vol 18-19 ◽  
pp. 213-218 ◽  
Author(s):  
Mahmood Aliofkhazraei ◽  
Alireza Sabour Rouhaghdam
Keyword(s):  
Tungsten Carbide ◽  
Duty Cycle ◽  
Treatment Time ◽  
Pure Titanium ◽  
White Paper ◽  
Nanocomposite Coating ◽  
Pulsed Current ◽  
Commercially Pure Titanium ◽  
Functionally Gradient ◽  
Plasma Electrolytic

In this paper, plasma electrolytic carburizing has been applied on the commercially pure titanium substrates in an organic based electrolyte with presence of some hard tungsten carbide nanoparticulates in suspension state. Pulsed current with variable duty cycle has been used for fabrication of functionally gradient nanocomposite coating. As a result, a hard nanocomposite layer has been formed on the surface of the samples with complex titanium carbide as its matrix and tungsten carbide nanoparticulates as its reinforced phase. In addition of used SEM, TEM and AFM for evaluation of coating nature, the presence of tungsten in different depths of formed layer has been followed by means of EDS. The effects of rate of variable duty cycle of applied pulsed current or treatment time have been described. Hardness profiles showed that the higher rates for variable duty cycles will cause lower hardness and sharper profilesThis document explains and demonstrates how to prepare your camera-ready manuscript for Trans Tech Publications. The best is to read these instructions and follow the outline of this text. The text area for your manuscript must be 17 cm wide and 25 cm high (6.7 and 9.8 inches, resp.). Do not place any text outside this area. Use good quality, white paper of approximately 21 x 29 cm or 8 x 11 inches (please do not change the document setting from A4 to letter). Your manuscript will be reduced by approximately 20% by the publisher. Please keep this in mind when designing your figures and tables etc.

EFFECT OF PULSE DUTY CYCLE ON PROPERTIES OF HARD NANOCRYSTALLINE SURFACE FABRICATED BY DUPLEX TREATMENTS

2009 ◽  
Vol 16 (03) ◽  
pp. 441-447 ◽  
Author(s):  
M. ALIOFKHAZRAEI ◽  
A. SABOUR ROUHAGHDAM
Keyword(s):  
Surface Roughness ◽  
Duty Cycle ◽  
Pulsed Current ◽  
Optimum Level ◽  
Fourth Moment ◽  
Pulsed Plasma ◽  
Surface Nanocrystallization ◽  
Moment Distribution ◽  
Duty Cycles ◽  
Plasma Electrolytic

Up to fourth moment distribution of carbide nanocrystallites produced by duplex treatments of surface nanocrystallization and pulsed plasma electrolytic carbonitriding on AISI 1010 mild steel was investigated by the means of figure analysis with high precision. Skewness and kurtosis study of the Gaussian distribution have been studied and the effect of duty cycle of pulsed current has been determined. The usage of lower duty cycles of pulsed current is more suitable for achieving lower sizes of carbide nanocrystallites. Surface roughness of treated samples was measured and it has been observed that there is an optimum level of duty cycle of pulsed current for surface roughness increasing (difference between two measured data).

Two-photon excitation microscopy in cellular biophysics

1995 ◽  
Vol 53 ◽  
pp. 62-63
Author(s):  
David W. Piston ◽  
Brian D. Bennett ◽  
Robert G. Summers
Keyword(s):  
Confocal Microscopy ◽  
Laser Beam ◽  
Duty Cycle ◽  
Excited Electronic State ◽  
Input Power ◽  
Two Photon ◽  
Simultaneous Absorption ◽  
Photon Excitation ◽  
Very High ◽  
Two Photon Excitation

Two-photon excitation microscopy (TPEM) provides attractive advantages over confocal microscopy for three-dimensionally resolved fluorescence imaging and photochemistry. Two-photon excitation arises from the simultaneous absorption of two photons in a single quantitized event whose probability is proportional to the square of the instantaneous intensity. For example, two red photons can cause the transition to an excited electronic state normally reached by absorption in the ultraviolet. In practice, two-photon excitation is made possible by the very high local instantaneous intensity provided by a combination of diffraction-limited focusing of a single laser beam in the microscope and the temporal concentration of 100 femtosecond pulses generated by a mode-locked laser. Resultant peak excitation intensities are 106 times greater than the CW intensities used in confocal microscopy, but the pulse duty cycle of 10-5 maintains the average input power on the order of 10 mW, only slightly greater than the power normally used in confocal microscopy.

Acoustic-Reflex Dynamics for Pulsed Signals

1978 ◽  
Vol 21 (2) ◽  
pp. 295-308
Author(s):  
Terry L. Wiley ◽  
Raymond S. Karlovich
Keyword(s):  
Duty Cycle ◽  
Acoustic Impedance ◽  
Normal Hearing ◽  
Broadband Noise ◽  
Threshold Shift ◽  
Temporary Threshold Shift ◽  
Acoustic Reflex ◽  
Stapedius Muscle ◽  
Duty Cycles

Contralateral acoustic-reflex measurements were taken for 10 normal-hearing subjects using a pulsed broadband noise as the reflex-activating signal. Acoustic impedance was measured at selected times during the on (response maximum) and off (response minimum) portions of the pulsed activator over a 2-min interval as a function of activator period and duty cycle. Major findings were that response maxima increased as a function of time for longer duty cycles and that response minima increased as a function of time for all duty cycles. It is hypothesized that these findings are attributable to the recovery characteristics of the stapedius muscle. An explanation of portions of the results from previous temporary threshold shift experiments on the basis of acoustic-reflex dynamics is proposed.

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