CORROSION BEHAVIORS OF ND: YAG LASER-GMA HYBRID WELDMENT OF AA5052-H32 Al ALLOYS

2009 ◽  
Vol 16 (01) ◽  
pp. 43-47
Author(s):  
DA-QUAN ZHANG ◽  
YOUNG WOO PARK ◽  
KANG YONG LEE
Keyword(s):  
Base Alloy ◽  
Galvanic Corrosion ◽  
Composition Analysis ◽  
Fusion Boundary ◽  
Yag Laser ◽  
Corrosion Behaviors ◽  
Acidic Chloride ◽  
Corrosion Susceptibility ◽  
Weld Fusion Zone ◽  
Galvanic Couples

This paper investigated the corrosion behaviors of the Nd: YAG laser-gas metal arc (GMA) AA5052-H32 weldments comparing with the base alloy. The corrosion susceptibility of weldments was higher than that of the base alloy. The weld fusion zone (WFZ) suffered the severe pitting in acidic chloride media. The zones adjacent to the weld fusion boundary showed less corrosion tendency. A corrosion cracking was associated with pitting in the weldments. The surface morphology observation and composition analysis were investigated by the scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) spectroscopy. At the WFZ/HAZ interface and the HAZ/base alloy interface, the galvanic corrosion coupling existed. From the comparison, the WFZ showed anodic behavior, the zone adjacent to the weld fusion boundary showed cathodic behavior. The corrosion of WFZ was progressed by the formation of the galvanic couples.

scholarly journals Effect of Galvanic Corrosion on the Degradability of Biomedical Magnesium

2021 ◽  
Vol 8 ◽  
Author(s):  
Hongzhou Peng ◽  
Wei Wang ◽  
Haomiao Jiang ◽  
Rui Zan ◽  
Yu Sun ◽  
...  
Keyword(s):  
Clinical Trials ◽  
High Purity ◽  
Galvanic Corrosion ◽  
Scale Up ◽  
Pure Titanium ◽  
Stainless Steel 316L ◽  
Metallic Implants ◽  
Corrosion Behaviors ◽  
Galvanic Couples ◽  
Biodegradable Magnesium

With recent progress in clinical trials and scale-up applications of biodegradable magnesium-based implants, the scenarios of transplanting biodegradable Mg with other non-degradable metals may occur inevitably. Galvanic corrosion appears between two metallic implants with different electrochemical potentials and leads to accelerated degradation. However, a quantitative measurement on the galvanic corrosion of Mg in contact with other metallic implants has not been conducted. Here we study the corrosion behaviors and mechanical attenuation of high purity magnesium (Mg)in contact with stainless steel (316L), pure titanium (TA2), and magnesium alloy (AZ91) respectively to form different galvanic couples in simulated body fluids. The results show that all of these three heterogeneous metal pairs accelerate the degradation of high purity Mg to different degrees, yielding declined tensile strength and mechanical failure after 4 days of immersion. Our observations alert the potential risk of co-implanting different metallic devices in clinical trials.

Corrosion of Electronic and Magnetic Devices and Materials

1996 ◽  
Vol 451 ◽  
Author(s):  
Gerald S. Frankel
Keyword(s):  
Thin Film ◽  
Failure Modes ◽  
Galvanic Corrosion ◽  
Potential Drop ◽  
Magnetic Devices ◽  
Disk Structure ◽  
Magnetic Layers ◽  
Ohmic Potential Drop ◽  
Corrosion Problem ◽  
Corrosion Susceptibility

ABSTRACTCorrosion of thin film structures commonly used in electronic and magnetic devices is discussed. Typical failure modes are presented, and galvanic corrosion is discussed in some detail since it is one common problem with such devices. A graphical explanation for the determination of the ohmic potential drop during galvanic corrosion is presented. The corrosion problem of thin film disks is shown to have changed during the past ten years owing to changes in disk structure. The corrosion susceptibility of two antiferromagnetic alloys used for exchange coupling to soft magnetic layers is discussed.

scholarly journals Effect of Laser Power on Microstructure and Micro-Galvanic Corrosion Behavior of a 6061-T6 Aluminum Alloy Welding Joints

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 3
Author(s):  
Huiling Zhou ◽  
Fanglian Fu ◽  
Zhixin Dai ◽  
Yanxin Qiao ◽  
Jian Chen ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Laser Power ◽  
Galvanic Corrosion ◽  
Gas Metal Arc Welding ◽  
Immersion Test ◽  
Intermetallic Particles ◽  
Metal Arc Welding ◽  
Corrosion Behaviors ◽  
Welding Joints ◽  
Corrosion Pits

The 6061-T6 aluminum alloy welding joints were fabricated using gas metal arc welding (GMAW) of various laser powers, and the effect of laser power on the microstructure evolution of the welding joints was investigated. The corrosion behaviors of 6061-T6 aluminum alloy welding joints were investigated in 3.5 wt% NaCl solution using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The results showed that the micro-galvanic corrosion initiation from Mg2Si or around the intermetallic particles (Al-Fe-Si) is observed after the immersion test due to the inhomogeneous nature of the microstructure. The preferential dissolution of the Mg2Si and Al-Fe-Si is believed to be the possible cause of pitting corrosion. When the laser power reached 5 kW, the microstructure of the welded joint mainly consisted of Al-Fe-Si rather than the Mg2Si at 2 kW. The relatively higher content of Al-Fe-Si with increasing in laser power would increase the volume of corrosion pits.

RETRACTED: Fretting and galvanic corrosion behaviors and mechanisms of Co–Cr–Mo and Ti–6Al–4V alloys

Wear ◽  
2001 ◽  
Vol 249 (10-11) ◽  
pp. 883-891 ◽  
Author(s):  
Daxiong He ◽  
Tiancheng Zhang ◽  
Yinshun Wu
Keyword(s):  
Galvanic Corrosion ◽  
Corrosion Behaviors

Numerical Modeling of Galvanic Corrosion Behaviors on Uranium Surface

2013 ◽  
Vol 702 ◽  
pp. 140-144
Author(s):  
Ping An Shi ◽  
Hong Liang Zhou
Keyword(s):  
Numerical Simulation ◽  
Current Distribution ◽  
Galvanic Corrosion ◽  
Corrosion Current ◽  
Electrode Kinetics ◽  
Uniform Corrosion ◽  
Corrosion Rates ◽  
Ohmic Resistance ◽  
Circular Defect ◽  
Corrosion Behaviors

The Uranium and Titanium corrosion rates are described by a Tafel’s relationship, and the cathodic protection of Uranium is a function of a Wagner number. A numerical simulation of galvanic corrosion of Uranium surface under thin layer electrolyte is presented. The model considered that the effect of a circular defect and oxygen reduction and corrosion in the Uranium surface, the effect of electrolyte thickness and conductivity and defect radius on corrosion current distribution of Uranium with is investigated. The results shows that the corrosion rate at the center is non-uniform, and it could lead to the formation of a hemispherical-shaped pit. And the effect of radius is to increase the importance of the electrode kinetics relative to ohmic resistance, and to increase the potential difference between the center and edge of the Uranium surface, resulting in non-uniform corrosion current distribution.

Effects of Temperature on Galvanic Corrosion Behaviors of Super 13Cr and P110 Steel Couples in NaCl Solution

2014 ◽  
Vol 1033-1034 ◽  
pp. 829-833 ◽  
Author(s):  
Xiao Fei Yao ◽  
Wei Tian ◽  
Ling Wu
Keyword(s):  
Current Density ◽  
Corrosion Current Density ◽  
Galvanic Corrosion ◽  
Corrosion Current ◽  
Potential Difference ◽  
Nacl Solution ◽  
P110 Steel ◽  
Corrosion Behaviors ◽  
Effects Of Temperature ◽  
Increasing Temperature

Electrochemical methods were employed to investigate galvanic corrosion behaviors of super13Cr and P110 couples in NaCl solution at different temperature. Corrosion morphologies and products of the couples were analyzed by SEM, EDS and XRD. The results showed that there were potential difference distinctly between super 13Cr and P110 steel in NaCl solution at different temperature, when its contacted, galvanic corrosion of super 13Cr-P110 steel couples will occurred. P110 was accelerated to corrode as anode and super 13Cr was protected as cathode in the coupling. Super 13Cr-P110 steel couples could not be used as P110 without any protection in NaCl solution at 20 °C to 80 °C. Corrosion current density and galvanic corrosion of super13Cr-P110 steel couples increased with increasing temperature in NaCl solution, of which corrosion products are Fe3O4.

scholarly journals Corrosion Behaviors of the Eutectic Structure in Zn-Al-Mg Alloy Coated Steel in Chloride Containing Aqueous Environment

2020 ◽  
Vol 58 (9) ◽  
pp. 610-616
Author(s):  
Jae-Won Lee ◽  
Se-Young Oh ◽  
Bora Park ◽  
Min-Suk Oh ◽  
Sung Jin Kim
Keyword(s):  
Coating Layer ◽  
Early Stage ◽  
Galvanic Corrosion ◽  
Salt Spray ◽  
Eutectic Structure ◽  
Mg Alloy ◽  
Aqueous Environment ◽  
Corrosion Mechanism ◽  
Coated Steel ◽  
Corrosion Behaviors

To clearly understand the effect of the eutectic structure in the Zn-Al-Mg alloy coating on the corrosion behaviors in chloride containing aqueous environments, a bulk Zn-MgZn<sub>2</sub> sample was fabricated by diffusion bonding process, and a variety of experiments, such as electrochemical polarization and galvanic corrosion measurements, salt spray tests, and cyclic corrosion tests, were carried out. This study revealed that the corrosion potential values of MgZn<sub>2</sub> and Zn samples exposed to a 5 wt.% of NaCl solution were approximately -1.5 and -1 VSCE, respectively, and the MgZn<sub>2</sub> showed a higher corrosion current density than Zn at the early stage of corrosion. The continued dissolution of MgZn<sub>2</sub> phase from the eutectic structure in the coating layer provides not only sacrificial protection, but also environmental conditions for the co-formation of two types of corrosion products (simonkoleite (Zn<sub>5</sub>(OH)<sub>8</sub>Cl<sub>2</sub>·H<sub>2</sub>O) and hydrotalcite (ZnAl<sub>2</sub>(OH)<sub>6</sub>Cl<sub>2</sub>·H<sub>2</sub>O)) which have an inhibiting effect on the outer surface. The formation areas and kinetics of the two products on the coating surface were different, and they were greatly dependent upon the types of eutectic structures in the coating layer. Based on the results, a modified anti-corrosion mechanism of Zn-Al-Mg alloy coated steel sheet in chloride containing aqueous environment was proposed.

scholarly journals Corrosion Behavior and Morphology of Passive Films Modified with Zinc–Aluminum Simultaneous Treatment on Different Metals

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 986
Author(s):  
Shenghan Zhang ◽  
Chenhao Sun ◽  
Jie Di ◽  
Yu Tan
Keyword(s):  
Energy Dispersive Spectrometry ◽  
Electrochemical Impedance ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Passive Films ◽  
Composition Analysis ◽  
304L Stainless Steel ◽  
Simultaneous Treatment ◽  
Incoloy 800 ◽  
Corrosion Behaviors

Passive films were formed on A508-3 steel (A508-3), 304L stainless steel (304L) and Incoloy 800 (In800) with blank/zinc/zinc–aluminum treatments in air at 300 °C. The electrochemical corrosion behaviors of different metals were investigated through potentiodynamic polarization, electrochemical impedance spectroscopy and the Mott–Schottky technique. The morphology and composition of passive films were analyzed using scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). The zinc–aluminum treatment effectively reduced the corrosion current and increased the impedance of A508-3 and 304L, but had a weak effect on In800. The zinc–aluminum treatment reduced the carrier concentration of A508-3 and changed the semiconductor property of 304L and In800. The order of zinc–aluminum treatment for improving the corrosion resistance of three metals was: A508-3 > 304L > In800. In addition, the zinc–aluminum treatment enhanced the density and smoothness of passive films. According to the composition analysis, spinel ZnAl2O4 was formed on three metals; however, the amount of spinel varied with the content of nickel and chromium in different metals, which affected the results of using this technology.

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