Effects of Ti-1023 Anodized Coating on Corrosion Behavior of Ti-1023/30CrMnSiA and Ti-1023/LY12 Galvanic Couples

2007 ◽  
Vol 546-549 ◽  
pp. 1821-1826
Author(s):  
Jian Hua Liu ◽  
Jun Xiu Shi ◽  
Song Mei Li ◽  
Jun Lan Yi
Keyword(s):  
Corrosion Potential ◽  
Galvanic Corrosion ◽  
Corrosion Current ◽  
Optical Microscope ◽  
Open Circuit ◽  
Corrosion Properties ◽  
Corrosion Morphology ◽  
Average Value ◽  
Galvanic Couples ◽  
Corrosion Mechanisms

Galvanic properties were evaluated on bare and anodized Ti-1023 titanium alloy which coupled to Ni-electroplated, Zn-electroplated, Cd-electroplated 30CrMnSiA and anodized LY12, respectively. Corrosion properties including open circuit potential (Eoc) of each material, galvanic corrosion potential (Eg), and corrosion current (Ig) of the couples were monitored in conjunction with a Model 263A potentiostat system. Corrosion current density (Īg) and average value of corrosion potential (Ēg) were calculated from Ig-time and Eg-time curves, respectively. Corrosion morphology was observed on a optical microscope (OM) and corrosion mechanisms were analyzed and discussed. The corrosion resistance of Ti-1023/LY12 couple was significantly improved by Ti-1023 anodized coating. However, the coating accelerated the dissolve of the three electroplated coatings in the other galvanic couples, resulting in a heavy corrosion attack on 30CrMnSiA steel.

Effects of Surface Oxide Coating on Corrosion Behavior of Ti-1023/LY12 Galvanic Couple

2013 ◽  
Vol 668 ◽  
pp. 880-884 ◽  
Author(s):  
Jun Xiu Shi ◽  
Jian Hua Liu
Keyword(s):  
Corrosion Behavior ◽  
Galvanic Corrosion ◽  
Oxide Coating ◽  
Optical Microscope ◽  
Open Circuit ◽  
Localized Corrosion ◽  
Corrosion Attack ◽  
Corrosion Properties ◽  
Corrosion Morphology ◽  
Galvanic Couple

Galvanic corrosion behavior of Ti-1023 titanium alloy coupled to LY12 aluminum alloy was investigated in 3.5% NaCl solution. Particular attention was given to the effect of anodized coatings on corrosion behaviors of Ti-1023/LY12 galvanic couple. Galvanic test was conducted on the following couples: Ti-1023/LY12, Ti-1023/anodized LY12 and anodized Ti-1023/anodized LY12, respectively. Corrosion properties including open circuit potential (Eoc) of each material, galvanic corrosion potential (Eg) and galvanic corrosion current (Ig) of the couples were monitored. Corrosion morphology was observed by optical microscope (OM) and corrosion mechanisms were analyzed and discussed. It was showed that anodized coatings significantly decreased Eg and Īg of the couples and provide effective protection of the anode from suffering corrosion attack. Only slight localized corrosion was detected on anodized LY12 alloy in the two anodized couples and the LY12 in anodized Ti-1023/anodized LY12 couple was found to be least susceptible to galvanic corrosion. The LY12 alloy in the bare couple: Ti-1023/LY12, was found to be highly susceptible to galvanic corrosion and suffered severe uniform and localized corrosion attack

scholarly journals Mechanical and Corrosion Properties of Mg-Based Alloys with Gd Addition

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1775 ◽  
Author(s):  
Aneta Kania ◽  
Ryszard Nowosielski ◽  
Agnieszka Gawlas-Mucha ◽  
Rafał Babilas
Keyword(s):  
Open Circuit Potential ◽  
Corrosion Potential ◽  
Orthopedic Implants ◽  
Corrosion Current ◽  
Medical Application ◽  
Open Circuit ◽  
Dendritic Microstructure ◽  
Corrosion Properties ◽  
Electrochemical Parameters ◽  
Mechanical And Corrosion Properties

Magnesium alloys with rare earth metals are very attractive materials for medical application because of satisfactory mechanical properties. Nevertheless, low corrosion resistance is an obstacle in the use of Mg alloys as resorbable orthopedic implants. The paper presents results of mechanical and corrosion properties of MgCa5-xZn1Gdx (x = 1, 2, and 3 wt. %) alloys. Based on the microscopic observations it was stated that the studied alloys show a dendritic microstructure with interdendritic solute rich regions. The phase analysis reveals an occurrence of α-Mg and Mg2Ca, Ca2Mg6Zn3 phases that are thermodynamic predictions, and stated Mg26Zn59Gd7 phases in MgCa5-xZn1Gdx (x = 1, 2, and 3 wt. %) alloys. The Mg26Zn59Gd7 phases are visible as lamellar precipitations along interdendritic regions. It was confirmed that an increase of Gd content from 1 to 3 wt. % improves ultimate tensile (Rm; from 74 to 89 MPa) and compressive strength (Rc; from 184 to 221 MPa). Moreover, the studied alloys are active in Ringer’s solution. They are characterized by an increase of corrosion potential (Ecorr) of about 150 mV in comparison with values of open circuit potential (EOCP). The best electrochemical parameters (e.g., corrosion current density, icorr, polarization resistance, Rp, and Ecorr) were obtained for the MgCa3Zn1Gd2 alloy.

Study on Corrosion Behavior of Ti-Ni-Nb Shape Memory Alloy and 1Cr18Ni9Ti Stainless Steel Aeroplane Pipe System

2013 ◽  
Vol 668 ◽  
pp. 808-813
Author(s):  
Jun Xiu Shi ◽  
Jian Hua Liu
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Corrosion Behavior ◽  
Galvanic Corrosion ◽  
Corrosion Current ◽  
Optical Microscope ◽  
Nacl Solution ◽  
Corrosion Morphology ◽  
Pipe System ◽  
Pipe Coupling

The susceptibility to stress corrosion cracking (SCC) and galvanic corrosion of an aeroplane pipe made of 1Cr18Ni9Ti connected with a pipe coupling that made of Ti-Ni-Nb shape memory alloy were evaluated. SCC test was completed under simulated service environment in 6% NaCl solution through a self-designed corrosive system. Galvanic corrosion behavior of Ti-Ni-Nb/1Cr18Ni9Ti couple was conducted in 3.5% NaCl solution at 30°C, in which galvanic corrosion current (Ig) and galvanic corrosion potential (Eg) were monitored. The corrosion morphology was observed by using scanning electronic microscope (SEM) and optical microscope (OM) after SCC test and galvanic test. It was showed that no obvious corrosion was detected on the surface of the whole pipe system after the simulated test. The two metals showed excellent resistance to SCC based on the section morphology observation. The average galvanic corrosion current of 1Cr18Ni9Ti/Ti-Ni-Nb couple was 0.13µA/cm2. No obvious corrosion pitting was detected on the surface of the two alloys by OM observation. Therefore, 1Cr18Ni9Ti pipe was safely connected with Ti-Ni-Nb pipe coupling in aeroplane pipe system.

scholarly journals Galvanic Corrosion of Copper / Nickel-Chrome Alloy in an Agitated Sulfuric Acid Solution

2018 ◽  
Vol 21 (1) ◽  
pp. 133
Author(s):  
Samar S. Hussein ◽  
Basim O. Hasan ◽  
Naseer A. Al-Haboubi
Keyword(s):  
Sulfuric Acid ◽  
Acid Solution ◽  
Sulfuric Acid Solution ◽  
Open Circuit Potential ◽  
Corrosion Potential ◽  
Galvanic Corrosion ◽  
Corrosion Current ◽  
Open Circuit ◽  
Flow Conditions ◽  
Galvanic Current

Galvanic corrosion of Nickel-Chrome alloy (Ni-Cr alloy) and Copper (Cu) coupled in 5% sulfuric acid solution was investigated. The effects of agitation velocity, temperature, and time on the galvanic corrosion current and the weight loss of both metals in both free corrosion and galvanic corrosion were investigated. The trends of open circuit potential (OCP) of each metal and galvanic potential (Eg) of the couple were also determined. The results showed that Cu was cathodic relative to Ni-Cr alloy in galvanic couple and the corrosion potential of the couple (Ni- Cr alloy /Cu) was between the values of the two single components because the OCP of copper shifted to positive with the increase in velocity. Under stagnant conditions initially the galvanic current was more negative then shifted to the positive with time. The corrosion of Ni-Cr alloy decreased with time because the passivation layer was formed on the surface. Under flow conditions, the galvanic current sharply shifted to the negative direction (increase galvanic current from Ni-Cr alloy (anode) to Cu (cathode) during the first few minutes.

Corrosion Properties of Al-Modified Austenitic Stainless Steel Prepared by Laser Cladding

2013 ◽  
Vol 331 ◽  
pp. 536-539
Author(s):  
Jian Bin Zhang ◽  
Dong Mei Yu ◽  
Jian Lin Xu
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Laser Cladding ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Optical Microscope ◽  
Anodic Polarization Curve ◽  
Corrosion Properties ◽  
Mixed Acid ◽  
Cladding Layer

The layer of Al-modified austenitic stainless steel was formed by laser cladding with pre-placed FeNiCrAl powder on 304SS surface. No porosity and free of cracks was observed at power density of 31.25 w·s·mm-2. The microstructure of cladded layer was observed by OM (optical microscope) and SEM (scanning electron microscope). Compared with 304 (the substrate), laser cladding FeNiCrAl layer exhibit excellent pitting resistance in mixed acid solution. Anodic polarization curve indicated that the corrosion potential of laser cladding layer was 70 mV higher than that of 304SS (-345.7 mV), while self-corrosion current density of 304SS was 2.4 times as high as that of laser cladding layer.

Corrosion Behaviour of In Situ AlxNiy Reinforced AA6061 Composite

2021 ◽  
Vol 882 ◽  
pp. 96-103
Author(s):  
A.D. Vishwanatha ◽  
D.M. Shivanna ◽  
Bijayani Panda
Keyword(s):  
Corrosion Potential ◽  
Corrosion Behaviour ◽  
Corrosion Current ◽  
Open Circuit ◽  
Homogeneous Distribution ◽  
Initial Increase ◽  
Weight Percentage ◽  
Aa6061 Alloy ◽  
Ni Addition

In-situ AlxNiy reinforced aluminium matrix composites (AMCs) were produced by stir-casting route by adding 5, 10 and 15 weight percentage (wt.%) of Ni to AA6061 aluminum alloy. The density, porosity, microstructure, hardness and corrosion behaviour of the as-cast AMCs was studied and compared with that of the as-cast AA6061 alloy. The porosity in all the castings was found to be less than 0.1%. Further, the porosity was found to decrease with increase in Ni addition. Optical microscopy studies showed that in-situ formed AlxNiy was distributed along the dendritic arms. The distribution became non-homogeneous and coarse with increase in AlxNiy content. The coarse distribution of AlxNiy in the AA6061 matrix also resulted in the decrease in hardness of the composite, after an initial increase in hardness till 10 wt.% Ni addition. The open circuit potential (OCP) and corrosion potential (Ecorr) of the AMCs with 5, 10 and 15 wt. of % Ni addition was noble than that of the AA6061 alloy. This was understood to be due to the presence of AlxNiy intermetallic which is known to have a noble corrosion potential than the aluminium alloy. However, the corrosion current (icorr) increased while the polarization resistance (Rp) decreased with increase in Ni addition in the AMC. This indicates that the coarse non-homogeneous distribution of in-situ AlxNiy had a detrimental effect on the corrosion performance of the AMCs.

scholarly journals Corrosion investigations of Al-Si casting alloys in 0.6 M NaCl solution

2021 ◽  
Vol 41 (3) ◽  
Author(s):  
Sunčana Smokvina Hanza ◽  
Ladislav Vrsalović ◽  
Lovro Štic ◽  
Lovro Liverić
Keyword(s):  
Potentiodynamic Polarization ◽  
Electrochemical Behavior ◽  
Die Casting ◽  
Electrochemical Corrosion ◽  
Microstructural Characterization ◽  
Casting Process ◽  
Corrosion Current ◽  
Optical Microscope ◽  
Open Circuit ◽  
Polarization Measurements

This paper presents results of the corrosion investigations of specimens made from finished parts for the automotive industry, produced by high-pressure die casting and gravity die casting process of six Al-Si alloys (40000 series). Open circuit potential and potentiodynamic polarization measurements have been performed using a potentiostat with three-electrode set-up in 0.6 M NaCl naturally aerated solution. Microstructural characterization before and after electrochemical investigations has been carried out with optical microscope to establish the connection between microstructure and corrosion parameters of investigated alloys and to analyze and record surface changes of each sample due to electrochemical corrosion. All alloys show good corrosion resistance, which manifests with low values of corrosion rates, calculated from the corrosion current densities obtained from potentiodynamic polarization measurements. Differences in electrochemical behavior appear due to the distinctions in their chemical composition and microstructure. The type of casting process does not affect electrochemical behavior of Al-Si alloys.

scholarly journals In-Situ Monitoring and Analysis of the Pitting Corrosion of Carbon Steel by Acoustic Emission

2019 ◽  
Vol 9 (4) ◽  
pp. 706 ◽  
Author(s):  
Junlei Tang ◽  
Junyang Li ◽  
Hu Wang ◽  
Yingying Wang ◽  
Geng Chen
Keyword(s):  
Acoustic Emission ◽  
Carbon Steel ◽  
Pitting Corrosion ◽  
Optical Microscope ◽  
Open Circuit ◽  
In Situ Monitoring ◽  
Localized Corrosion ◽  
Uniform Corrosion ◽  
Corrosion Morphology

The acoustic emission (AE) technique was applied to monitor the pitting corrosion of carbon steel in NaHCO3 + NaCl solutions. The open circuit potential (OCP) measurement and corrosion morphology in-situ capturing using an optical microscope were conducted during AE monitoring. The corrosion micromorphology was characterized with a scanning electron microscope (SEM). The propagation behavior and AE features of natural pitting on carbon steel were investigated. After completion of the signal processing, including pre-treatment, shape preserving interpolation, and denoising, for raw AE waveforms, three types of AE signals were classified in the correlation diagrams of the new waveform parameters. Finally, a 2D pattern recognition method was established to calculate the similarity of different continuous AE graphics, which is quite effective to distinguish the localized corrosion from uniform corrosion.

scholarly journals Corrosion Behavior of As-Cast Binary Mg-Dy Alloys

2011 ◽  
Vol 690 ◽  
pp. 417-421 ◽  
Author(s):  
Lei Yang ◽  
Frank Feyerabend ◽  
Karl Ulrich Kainer ◽  
Regine Willumeit ◽  
Norbert Hort
Keyword(s):  
Corrosion Rate ◽  
Optical Microscope ◽  
Direct Chill ◽  
Second Phase ◽  
Alloying Element ◽  
High Solubility ◽  
Corrosion Properties ◽  
Corrosion Morphology ◽  
Filiform Corrosion ◽  
Very High

The addition of rare earth elements (REE) is an effective way to improve the corrosion properties of magnesium alloys. Dysprosium has a very high solubility in Mg (25.3 wt.% at 561 °C) and could therefore be a promising alloying element for Mg based implants. In this study, four binary Mg-xDy (x=5, 10, 15 and 20 in wt.%) alloys were prepared by permanent mould direct chill casting. Microstructure and Dy distribution were investigated using optical microscope and EDX analysis. Corrosion rate was measured with hydrogen evolution method and corrosion morphology was observed after immersion for different time in 0.9 wt% NaCl solution with optical and SEM. The results show that with the increase of Dy, the amount of Dy in Mg matrix and area of Dy segregation are both increased. At the same time, the amount of second phase is also increased. Filiform corrosion is reduced while pitting corrosion is increased with the increment of Dy. As a result, lowest corrosion rate is obtained at Mg-10Dy alloy.

scholarly journals Peculiarities in structure formation and corrosion of cast quasicrystalline Al63Cu25Fe12 and Al63Co24Cu13 alloys in sodium chloride aqueous solution

2020 ◽  
Vol 21 (3) ◽  
pp. 530-536
Author(s):  
O. V. Sukhova ◽  
V. A. Polonskyy
Keyword(s):  
Sodium Chloride ◽  
Chloride Solution ◽  
Sodium Chloride Solution ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Corrosion Properties ◽  
Free Corrosion Potential ◽  
X Ray ◽  
Marine Climate ◽  
Potentiodynamic Method

In this work the structure and corrosion behavior of quasicrystalline cast Al63Cu25Fe12 and Al63Co24Cu13 alloys in 5-% sodium chloride solution (рН 6.9–7.1) were investigated. The alloys were cooled at 5 К/s. The structure of the samples was studied by methods of quantitative metallography, X-ray analysis, and scanning electron microscopy. Corrosion properties were determined by the potentiodynamic method. The made investigations confirm the formation of stable quasicrystalline icosahedral (y) and decagonal (D) phases in the structure of Al63Cu25Fe12 and Al63Co24Cu13 alloys correspondingly. In 5-% sodium chloride solution, the investigated alloys corrode under electrochemical mechanisms with oxygen depolarization. Compared with Al63Cu25Fe12 alloy, Al63Co24Cu13 alloy has a less negative value of free corrosion potential (–0.43 V and–0.66 V, respectively), and its electrochemical passivity region extends due to the inhibition of anodic processes. A corrosion current density, calculated from (E,lgi)-curve, for Al63Co24Cu13 alloy amounts to 0.18 mА/сm2 and for Al63Cu25Fe12 alloy – to 0.20 mА/сm2. The lower corrosion resistance of Al63Cu25Fe12 alloy may be explained by the presence of iron-containing phases in its structure. Based on obtained results, the Al63Co24Cu13 alloy was recommended as a coating material for rocket-and-space equipment working in a marine climate.

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