Effect of Zn Content on the Microstructure and Corrosion Behaviour of Mg-7Y-0.6Zr Alloy

2013 ◽  
Vol 765 ◽  
pp. 612-617
Author(s):  
Jian Li Wang ◽  
Jian Ping Li ◽  
Ping Wang ◽  
Yong Chun Guo ◽  
Zhong Yang
Keyword(s):  
Corrosion Rate ◽  
Corrosion Potential ◽  
Volume Fraction ◽  
Corrosion Behaviour ◽  
Secondary Phase ◽  
Immersion Test ◽  
Electrochemical Tests ◽  
Method Effect ◽  
Zn Content ◽  
Mould Casting

Mg-7Y-0.6Zr-xZn (x = 0, 0.5, 1.0, 1.5, 2.0, 2.5, wt.%) alloys were prepared by the metal mould casting method. Effect of Zn content on the microstructures and corrosion behaviour were investigated. Results showed that microstructures were refined and volume fraction of secondary phase Mg24(YZn)5 was increased with increasing addition of Zn element. Results of electrochemical tests demonstrated that the corrosion potential of Mg-7Y-0.6Zr alloy was about -1.77 V, and, with addition of 0.5~2.0 wt.% Zn element, corrosion potential moved to more positive values than that of Mg-7Y-0.6Zr alloy. Mg-7Y-0.6Zr-0.5Zn alloy possessed the most positive corrosion potential of -1.53 V. The results of immersion test with different time also indicated that corrosion rate could be decreased by addition of 0.5~2.0 wt.% Zn, and Mg-7Y-0.6Zr-0.5Zn alloy exhibited the lowest corrosion rate.

Influences of Zinc Content and Solution Heat Treatment on Microstructure and Corrosion Behavior of Mg-Zn Binary Alloys

CORROSION ◽  
10.5006/3672 ◽  
2020 ◽  
Author(s):  
Dinh Pham ◽  
Sachiko Hiromoto ◽  
Equo Kobayashi
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Volume Fraction ◽  
Galvanic Corrosion ◽  
Zinc Content ◽  
Eutectic Cell ◽  
Zn Content ◽  
Cast Alloys

The influences of Zn content and heat treatment on microstructure and corrosion behavior of Mg-xZn (x=1, 3, 5 and 7 wt.%) alloys were studied. (α-Mg + MgZn) eutectic cells and Zn-segregated regions were formed in the as-cast alloys. The Zn-rich phases acted as micro-cathodes in galvanic corrosion. Volume fraction of the Zn-rich phases increased with Zn content of the as-cast alloys, leading to a decrease in corrosion resistance. The corrosion rate of the as-cast alloys increased by 4 times with an increase of the volume fraction of eutectic cell from 0.07 vol.% of Mg-1Zn alloy to 2.18 vol.% of Mg-5Zn alloy. The corrosion rate of Mg-7Zn alloy with 2.87 vol% eutectic cells was 2 times higher than that of Mg-5Zn alloy. The Zn-rich phases dissolved by the T4 treatment and only the T4-treated Mg-7Zn alloy obviously showed eutectic cells of 1.73 vol.%. The polarization resistance (Rp) of the T4-treated Mg-1, 3 and 5Zn alloys was 2-10 times higher than that of the as-cast alloys. The T4-treated Mg-7Zn showed similar Rp to the as-cast Mg-5Zn alloy. Consequently, the volume fraction of Zn-rich phases dominated the corrosion resistance of Mg-xZn alloys.

ZnO Nanoparticles for Anti-Corrosion Nanocoating of Carbon Steel

2017 ◽  
Vol 894 ◽  
pp. 76-80 ◽  
Author(s):  
J.N. Hasnidawani ◽  
Noor Azlina Hassan ◽  
Hassan Norita ◽  
Noorasikin Samat ◽  
Noor Najmi Bonnia ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Carbon Steel ◽  
Corrosion Rate ◽  
Mild Steel ◽  
Corrosion Behaviour ◽  
Oxide Coating ◽  
Immersion Test ◽  
Nacl Solution ◽  
Corrosion Resistant ◽  
Naoh Solution

Nanostructured coatings offer great potential for various applications due to their superior characteristics that are not typically found in conventional coatings. This research aimed at developing a new and improved coating that employs zinc oxide nanopowder as the agent to achieve corrosion resistant properties for a coating. The research project discusses on its corrosion behaviour of epoxy-zinc oxide in different media by measuring its corrosion rate. Mild carbon steel was used as the substrate for the epoxy-zinc oxide coating. The corrosion behavior mechanism of mild steel was investigated in different media, namely fresh water, NaCl solution, HCl solution and NaOH solution. Immersion test was conducted and studied for a period of 60 days, with daily and weekly weighing and immersing. The corrosion rate was calculated and mild steel corrodes in the different environment and degrades in the following trend; HCl → NaCl → NaOH → H2O.

scholarly journals Corrosion Behaviour of Mg98.5Nd1Zn0.5 (at. %) Alloy in Phosphate Buffered Saline Solution

Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 148
Author(s):  
Sandra Cabeza ◽  
Pablo Pérez Zubiaur ◽  
Gerardo Garcés ◽  
Carmen Andrade ◽  
Paloma Adeva
Keyword(s):  
Corrosion Rate ◽  
Volume Fraction ◽  
Corrosion Behaviour ◽  
Hot Extrusion ◽  
High Volume ◽  
Hydrogen Release ◽  
Potential Candidate ◽  
Electrochemical Testing ◽  
Average Grain Size ◽  
Phosphate Buffered Saline

The corrosion behaviour of Mg98.5-Nd1-Zn0.5 (at. %) alloy was studied in phosphate buffered saline (PBS) solution to evaluate its degradation performance as a potential candidate for biomedical applications. The alloy, produced by casting and hot extrusion, consists of a fine-grained magnesium matrix with an average grain size of 3.8 μm embedding a high volume fraction of (Mg, Zn)12Nd precipitates. Hydrogen release tests revealed a stable low corrosion rate of 0.6 mm/year after 24 h of immersion. Electrochemical testing data proved good correlation with the data from hydrogen evolution, with the corrosion rate stabilizing below 1 mm/year.

Effect of adding rare-earth cerium on the microstructure and acid rain corrosion resistance of the ADC12 alloy

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
LiJie Zhang ◽  
Hong Yan ◽  
YongCheng Zou ◽  
BaoBiao Yu ◽  
Zhi Hu
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Acid Rain ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
The Self ◽  
Electrochemical Tests ◽  
Immersion Corrosion ◽  
Eutectic Si

Abstract The effect of adding cerium on the microstructure and acid rain corrosion resistance of the AlSi11Cu3 alloy was investigated by means of optical microscopy, scanning electron microscopy, and energy dispersive spectroscopy. The AlSi11Cu3 alloy was doped with varying stoichiometries of cerium to generate AlSi11Cu3-xCe, where x = 0, 0.5, 1.0, and 1.5 wt.%. The results show that the α-Al, eutectic Si, and β-Al5FeSi phases in the AlSi11Cu3-1.0Ce alloy are significantly refined. Electrochemical tests demonstrated an increase in the self-corrosion potential value of the AlSi11Cu3-1.0Ce alloy from –670 mV to –628 mV relative to the untreated alloy. In addition, the AlSi11Cu3-1.0Ce alloy has the lowest corrosion current density (8.4 μA × cm–2). Immersion corrosion testing on the AlSi11Cu3-1.0Ce alloy revealed a corrosion rate of 0.71 mg × cm–2 × d–1, constituting a 72% reduction in the corrosion rate compared to the untreated alloy. These results indicate that the AlSi11Cu3-1.0Ce alloy has a high resistance to acid rain corrosion, which is the result of a refinement of the cathode phases.

scholarly journals The influence of deformation on the corrosion properties of the material

2017 ◽  
Vol 61 (3) ◽  
pp. 86-90 ◽  
Author(s):  
M. Nováková ◽  
O. Chocholatý ◽  
A. Kříž
Keyword(s):  
Corrosion Rate ◽  
Tensile Stress ◽  
Electric Current ◽  
Polarization Resistance ◽  
Corrosion Potential ◽  
Corrosion Behaviour ◽  
Corrosion Properties ◽  
Titanium Grade ◽  
Changes Over Time ◽  
Over Time

Abstract This work was focused on changes of corrosion behaviour influence of deformation. The This work focuses on changes in corrosion behaviour under the influence of deformation. The main purpose is to observe the changes caused by tensile stress. The experimental material used is steel 1.4301 and titanium GRADE 2. The measurements were carried out using a potentiostat, which measures potential changes over time and electric current. The electrolyte used was 3.5% NaCl. Corrosion properties, especially polarization resistance, corrosion potential and corrosion rate, were evaluated from the measurements. The results demonstrate the changing corrosion properties depending on deformation. The corrosion properties worsened as the deformation increased.

Microstructure, hardness and corrosion behaviour of friction-stir processed AA5083

2019 ◽  
Vol 66 (6) ◽  
pp. 791-801 ◽  
Author(s):  
Vaira Vignesh Ramalingam ◽  
Padmanaban Ramasamy ◽  
Madhav Datta
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Corrosion Behaviour ◽  
Base Material ◽  
Secondary Phase ◽  
Corrosion Mechanism ◽  
Secondary Phases ◽  
Content Type ◽  
Friction Stir ◽  
Fine Dispersion

Purpose The purpose of this study is to refine the microstructure and improve the corrosion behaviour of aluminium alloy AA5083 by subjecting it to friction stir processing (FSP). Design/methodology/approach FSP trials are conducted as per central composite design, by varying tool rotation speed, tool traverse speed and shoulder diameter at three levels. The microstructure is examined and the hardness is measured for both the base material and the processed workpieces. The corrosion behaviour of the base material and processed workpieces is studied using potentiodynamic polarization technique for three different testing temperatures, and the corrosion current and corrosion rate are calculated. Findings The results reveal that FSP refined the grains, dispersed secondary phases, increased the hardness and improved the corrosion resistance of most of the friction stir processed specimens than the base material at all the three testing temperatures. Grain refinement and fine dispersion of ß phase improves the hardness and corrosion resistance of most of the FSPed specimens. However partial dissolution of ß phase decreases the hardness in some of the specimens. Most of the FSPed specimens displayed more positive potential than the base material at all the testing temperatures representing a higher nobility than the base material, as a result of fine dispersion of secondary phase particles in the matrix. Large pits formed on the surface of the base specimen indicating a higher corrosion rate at all three testing temperatures. The SEM image of FSPed specimens reveals the occurrence of very few pits and minimal corrosion products on the surface, which indicates lower corrosion rate. Originality/value The corrosion mechanism of the friction stir-processed AA5083 specimens is found to be a combination of activation and concentration polarization.

Influence of Metallographic Etchant on γ’ Precipitates Characterization in a Single Crystal Nickel-Base Superalloy

2016 ◽  
Vol 849 ◽  
pp. 563-569 ◽  
Author(s):  
Xiao Li Zhuang ◽  
Hong Yu Wu ◽  
Jia Yong Si ◽  
Liang Jiang
Keyword(s):  
Single Crystal ◽  
Corrosion Potential ◽  
Volume Fraction ◽  
Electrochemical Process ◽  
Nickel Base Superalloy ◽  
Analysis Software ◽  
Electrochemical Tests ◽  
Potentiodynamic Polarization Curves ◽  
Nickel Base ◽  
Base Superalloy

Two metallographic etchants were employed to characterize the γ′ precipitates in a single crystal Nickel-base superalloy. One can corrode γ matrix and retain γ′ precipitates, while the other one can remove γ′ and obtain γ. Potentiodynamic polarization curves of γ′ precipitates and γ matrix in these two etchants were measured to examine the electrochemical process of metallographic etching. The results from the electrochemical tests showed that the corrosion potential (Ecorr) of each phase determined the metallographic etching morphology. For γ′ volume fraction evaluation, the quantitative analysis by image analysis software was carried out with the electrolytically extracted γ′ precipitates for the same specimen. Statistics showed that the etchant which selectively etched γ′ precipitates can provide appropriate results.

Microstructural and Corrosion Behavior of Biodegradable Magnesium Alloys for Biomedical Implant

2015 ◽  
Vol 819 ◽  
pp. 331-336
Author(s):  
H.Y. Tok ◽  
Esah Hamzah ◽  
Hamid Reza Bakhsheshi-Rad
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Microstructural Analysis ◽  
Corrosion Current ◽  
Immersion Test ◽  
Ternary Alloys ◽  
Corrosion Properties ◽  
X Ray ◽  
Electrochemical Tests ◽  
Production Of Hydrogen

Magnesium and its alloys have great potential as biodegradable metallic implant materials with good mechanical properties. However, the poor corrosion rate and the production of hydrogen during degradation hindered its application. Binary alloy, Mg-3Ca and ternary alloy, Mg-3Ca-3Zn alloy were studied to investigate their bio-corrosion properties. Microstructure evolution and surfaces of corroded alloys were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The bio-corrosion behavior of the Mg alloys was investigated using immersion and electrochemical tests in Kokubo solution. Microstructural analysis showed that binary Mg-3Ca alloy consisted of α-Mg and Mg2Ca phases and ternary Mg-3Ca-3Zn alloy consisted of α-Mg, Ca2Mg6Zn3 and Mg2Ca phases. These phases had significant effect on the corrosion resistant of the alloy. Electrochemical test showed an improvement in ternary alloys where the corrosion current density reduced from 0.497 mA/cm2 in Mg-3Ca to 0.312 mA/cm2 in Mg-3Ca-3Zn alloy. Ternary Mg-3Ca-3Zn showed significant lower corrosion rate (1.1 mg/cm2/day) compared to binary Mg-3Ca (5.8 mg/cm2/day) alloy after 14 days immersion test.

Biodegradable Iron-Based Foams for Potential Bone Replacement Material

2020 ◽  
Vol 405 ◽  
pp. 151-156
Author(s):  
Monika Hrubovčáková ◽  
Miroslav Džupon ◽  
Miriam Kupková ◽  
Renáta Oriňáková
Keyword(s):  
Mechanical Properties ◽  
Corrosion Rate ◽  
Corrosion Behaviour ◽  
Three Dimensional ◽  
Immersion Test ◽  
Bone Graft Substitutes ◽  
Open Cell Foams ◽  
Hank’S Solution ◽  
Positive Effect ◽  
Potential Use

Iron and iron-phosphorus open-cell foams were tested for their potential use as synthetic bone graft substitutes. The samples were manufactured using a replica method based on a powder metallurgical approach. Iron foams alloyed with 0.5 wt. % of phosphorus were prepared with the aim of enhancing the mechanical properties and manipulating the corrosion rate. The manufactured foams were tested for their microstructure, porosity, corrosion behaviour and mechanical properties. SEM analyses of the foams’ microstructures confirmed the presence of an open, three-dimensional interconnected macroporous network similar to that of the human bone. The corrosion behaviour was studied by a static immersion test and potentiodynamic polarisation in Hank’s solution. The results showed that the presence of phosphorus slightly decreased the corrosion rate as compared to pure iron foams. The mechanical properties studied by a compression test confirmed a positive effect of phosphorus on the mechanical properties of the manufactured foams.

scholarly journals Corrosion Behavior of AZ91D Magnesium Alloy with a Calcium–Phosphate–Vanadium Composite Conversion Coating

Coatings ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 379
Author(s):  
Ruixue Sun ◽  
Shuaikang Yang ◽  
Tao Lv
Keyword(s):  
Calcium Phosphate ◽  
Corrosion Behaviour ◽  
Chemical Conversion ◽  
Compound Layer ◽  
Immersion Test ◽  
Anticorrosion Property ◽  
Self Healing ◽  
Vanadium Concentration ◽  
Electrochemical Tests ◽  
Damaged Zone

A novel self-healing calcium–phosphate–vanadium (Ca–P–V) composite coating on Mg alloy was successfully fabricated through a chemical conversion method. The effects of the vanadium concentration on the anticorrosion property of the substrate were also tested. The Ca–P–V coating with the main composition of CaHPO4, Ca3(PO4)2, and Mg3(PO4)2, with some hydroxides of V(V) dispersed into it has a similar morphology to the single vanadium coating. The corrosion behaviour of the Ca–P–V coating was studied through the electrochemical tests and the scratch immersion test in 3.5 wt % NaCl solution. The results showed that the Ca–P–V coated samples not only exhibit good corrosion resistance property, but also show self-healing ability. The ions of Ca, P, and V released from the coating can migrate in the corrosion solution and form a new compound layer on the damaged zone.

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