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

Author(s):  
V. T. Fomichev ◽  
A. V. Savchenko ◽  
G. P. Gubarevich

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.

Electronics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 805
Author(s):  
Shi Zuo ◽  
Jianzhong Zhao ◽  
Yumei Zhou

This article presents a low power digital controlled oscillator (DCO) with an ultra low power duty cycle correction (DCC) scheme. The DCO with the complementary cross-coupled topology uses the controllable tail resistor to improve the tail current efficiency. A robust duty cycle correction (DCC) scheme is introduced to replace self-biased inverters to save power further. The proposed DCO is implemented in a Semiconductor Manufacturing International Corporation (SMIC) 40 nm CMOS process. The measured phase noise at room temperature is −115 dBc/Hz at 1 MHz offset with a dissipation of 210 μμW at an oscillating frequency of 2.12 GHz, and the resulin figure-of-merit is s −189 dBc/Hz.


2016 ◽  
Vol 24 (05) ◽  
pp. 1750066 ◽  
Author(s):  
HAMED RAHMANI ◽  
MAHMOOD ALIOFKHAZRAEI ◽  
ABDOSSALAM KARIMZADEH

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.


2018 ◽  
Vol 23 (2) ◽  
pp. 3-10
Author(s):  
Ewa Osuchowska ◽  
Zofia Buczko ◽  
Klaudia Olkowicz

In the present work, the electrodeposition process of Zn-Cr alloy coatings under the conditions of direct and pulse current was discussed. Changes in the Cr content in the obtained alloy coatings, current efficiency of the process, surface morphology, structure and microhardness as a function of chromium(III) concentration in the bath to deposition, current density (direct and pulse) and solution mixing were determined. Surface morphology, structure and hardness of the obtained coatings were investigated. The Zn-Cr alloy coatings of good quality contained up to 0.25 %Cr (for direct current) and up to 9% Cr (for pulse current). The tested Zn-Cr alloy coatings obtained under pulse current conditions showed higher microhardness than the Zn-Cr coatings obtained under direct current conditions and than zinc coatings.


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

2015 ◽  
Vol 713-715 ◽  
pp. 2839-2842
Author(s):  
Fu Rong Zhou ◽  
Hu Zhang

Diisopropylamine methyl urea (DMU) was synthesized by raw materials of diisopropylamine, paraformaldehyde and urea in acid media, the effect of synthesis conditions including the dosage of hydrochloric acid, the mole ratio of the materials and the reaction temperature on the product yield were studied. A corrosion inhibitor formula that contained DMU, cyclohexylamine, ethanolamine and propiolic alcohol were designed, and static weight-loss method, Tafel polarization curve method were used to evaluate the corrosion inhibitory performance. The results showed that the best synthetic conditions for DMU were the mole ratio of diisopropylamine, paraformaldehyde and urea, 1:1.2:1; reaction temperature, 80°C; the mole ratio of hydrochloric acid and diisopropylamine 1.2:1. The product yield in this condition was 90.23%, the melting point was 230°C. The results of static weight-loss method revealed that DMU, cyclohexylamine, ethanolamine and propiolic alcohol had great synergy effect, the inhibition efficiency of gas phase static weight-loss method reached to 97.61%, and attained 85.20% in liquid phase static weight-loss method. The results of Tafel polarization curve method indicated that the corrosion inhibitor formula contained DMU had a good inhibitory effect to the cathode electrochemical corrosion process of A3 carbon steel.


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