Corrosion Properties of Supersaturated Magnesium Alloy Systems

2007 ◽  
Vol 539-543 ◽  
pp. 1679-1684 ◽  
Author(s):  
Carsten Blawert ◽  
V. Heitmann ◽  
Wolfgang Dietzel ◽  
M. Störmer ◽  
Y. Bohne ◽  
...  
Keyword(s):  
Magnesium Alloys ◽  
Electrochemical Impedance ◽  
Ion Beam ◽  
Alloying Elements ◽  
Pvd Coatings ◽  
Corrosion Properties ◽  
Cast Material ◽  
Linear Polarization Resistance ◽  
Melting Temperatures ◽  
Alloy Systems

The range of applications for magnesium alloys is still limited due to their relatively poor corrosion behavior. In recent years, various new magnesium alloys were developed, some of them with improved corrosion properties, thus opening new fields of application. However, the number of alloying elements for the use in conventional cast processes is limited due to their interaction with liquid magnesium, other alloying elements or large differences in the melting temperatures. The possibilities for grain refinement by post-processing are also restricted. PVD techniques can help to produce supersaturated precipitation free and microcrystalline magnesium layers. Using ion beam and magnetron sputtering, binary or ternary Mg-Al, Mg-Ti and Mg-Sn alloy systems as well as standard alloys (AM50, AZ91 and AE42) were deposited on silicon and on magnesium substrates. The effect of the microstructure on the corrosion properties was studied by comparing as cast material and PVD coatings using potentiodynamic polarization, linear polarization resistance, and electrochemical impedance techniques.

AZ31 and WE43 Alloys for Biomedical Applications

2017 ◽  
Vol 270 ◽  
pp. 205-211 ◽  
Author(s):  
Drahomír Dvorský ◽  
Jiří Kubásek ◽  
Dalibor Vojtěch
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloys ◽  
Biomedical Applications ◽  
Intermetallic Phases ◽  
Alloying Elements ◽  
Biodegradable Implants ◽  
Preparation Process ◽  
Magnesium Matrix ◽  
Corrosion Properties ◽  
Mechanical And Corrosion Properties

Magnesium and its alloys are considered for application as materials for biodegradable implants as they have mechanical properties similar to bone tissue. High demands on corrosion and mechanical properties are made on these alloys. While mechanical properties of magnesium are usually enhanced by alloying, corrosion properties may deteriorate. This paper is focused on the comparison of magnesium alloys AZ31 (3 wt. % Al, 1 wt. % Zn) and WE43 (4 wt. % Y, 3 wt. % Nd) which are considered for biomedical applications. Besides the type of alloying elements, the preparation process has also great impact on final mechanical and corrosion properties. Alloying elements may be dissolved in magnesium matrix or they can form intermetallic phases, which alter final properties. Microstructure, mechanical and corrosion properties of AZ31 and WE43 were studied and compared with pure magnesium.

Electrochemical corrosion study of Pb-free solders

2006 ◽  
Vol 21 (1) ◽  
pp. 62-70 ◽  
Author(s):  
B.Y. Wu ◽  
Y.C. Chan ◽  
M.O. Alam ◽  
W. Jillek
Keyword(s):  
Acid Solution ◽  
Corrosion Behavior ◽  
Current Density ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Corrosion Properties ◽  
Linear Polarization Resistance ◽  
Eis Measurements

This paper presents an investigation on the corrosion behavior of five solders by means of polarization and electrochemical impedance spectroscopy (EIS) measurements. The Sn–9Zn and Sn–8Zn–3Bi solder, in comparison with the Sn–3.5Ag–0.5Cu and Sn–3.5Ag–0.5Cu–9In solder, were tested in 3.5 wt% NaCl solution and 0.1 wt% adipic acid solution, respectively. The Sn–37Pb solder was for reference in this work. The polarization curves indicated that the Sn–9Zn and Sn–8Zn–3Bi solder showed the worst corrosion resistance both in the salt and acid solutions, in terms of corrosion-current density, corrosion potential, linear polarization resistance, and passivation-current density. Meanwhile, the Sn–3.5Ag–0.5Cu solder remained the best corrosion characteristics in both solutions. It was found that due to microstructure alteration, Bi additive to the Sn–9Zn solder improved the corrosion behavior in the salt solution, whereas decreased that in the acid solution. However, the additive of In degraded the Sn–3.5Ag–0.5Cu solder in both solutions. The EIS results agreed well with the noble sequence of the five solders subjected to the two solutions with polarization. The equivalent circuits were also determined. Nevertheless, the four Pb-free solders exhibited acceptable corrosion properties since there was not much difference of key corrosion parameters between them and the Sn–37Pb solder.

Anti-corrosion performances of hybrid silane coatings on AZ31 alloy

2018 ◽  
Vol 65 (3) ◽  
pp. 317-324 ◽  
Author(s):  
Luigi Calabrese ◽  
Angela Caprì ◽  
Edoardo Proverbio
Keyword(s):  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Electrochemical Impedance ◽  
Direct Synthesis ◽  
Sol Gel ◽  
Corrosion Properties ◽  
Surface Pretreatment ◽  
Content Type ◽  
Zeolite Content ◽  
Zeolite Coating

Purpose This paper aims to evaluate the efficacy of a zeolite-filled silane sol–gel coating as protective layer on pretreated AZ31 magnesium alloy substrates. Design/methodology/approach Anti-corrosion properties of a silane–zeolite composite coating, at various zeolite content, have been investigated on AZ31 magnesium substrates subjected to different surface pretreatment procedures before coating deposition. A short time etching by hydrofluoric acid (HF) and an anodic polarization in NaOH solution were used as surface pretreatments. Findings High hydrophobicity and good adhesion performances of coatings have been observed. Corrosion protection performance, during immersion in 3.5 per cent NaCl solution, was evaluated by means of electrochemical impedance spectroscopy tests. All coating formulations evidenced good barrier properties. Better durability properties have been shown by coating obtained on HF pretreated magnesium substrate and with a 60 per cent of zeolite content. Originality/value High electrochemical reactivity of magnesium alloys represents the mayor limit of its application in many different fields. In this concern, zeolite-based coatings are emerging as potentially effective environmentally friendly coating for metallic substrates. Despite aluminum and stainless steel substrates, in the literature, only expensive direct synthesis zeolite coating was investigated for its application on magnesium alloys protection. For this reason, this paper fulfills the need to assess the adhesion and anti-corrosion behavior of sol–gel silane–zeolite coating in magnesium alloy substrates.

scholarly journals Alloying Elements of Magnesium Alloys: A Literature Review

2021 ◽  
Author(s):  
Nouha Loukil
Keyword(s):  
Mechanical Properties ◽  
Rare Earth ◽  
Magnesium Alloys ◽  
Clinical Applications ◽  
Mg Alloys ◽  
Alloying Elements ◽  
Strengthening Mechanisms ◽  
Corrosion Properties ◽  
Lightweight Structures ◽  
Re Elements

Magnesium alloys are the lightest structural metal. The lightness is the main reason for the interest for Mg in various industrial and clinical applications, in which lightweight structures are in high demand. Recent research and developments on magnesium Mg alloys are reviewed. A particular attention is focused on binary and ternary Mg alloys consisting mainly of Al, Zn, Mn, Ca and rare earth (RE) elements. The effects of different alloying elements on the microstructure, the mechanical and the corrosion properties of Mg alloys are described. Alloying induces modifications of the microstructural characteristics leading to strengthening mechanisms, improving then the ductility and the mechanical properties of pure Mg.

Influence of irradiation intensity on corrosion properties of microarc oxidation film on AZ31 magnesium alloy with HIPIB

2019 ◽  
Vol 66 (4) ◽  
pp. 418-424
Author(s):  
X.G. Han ◽  
J.F. Lv ◽  
Y.Z. Chen ◽  
Y.C. Shan ◽  
J.J. Xu
Keyword(s):  
Magnesium Alloy ◽  
Electrochemical Impedance ◽  
Ion Beam ◽  
Substrate Surface ◽  
Microarc Oxidation ◽  
Film Surface ◽  
Az31 Magnesium Alloy ◽  
Electrochemical Impedance Spectrum ◽  
Corrosion Properties ◽  
Content Type

Purpose The purpose of this paper is to investigate the effect of high-intensity pulsed ion beam (HIPIB) intensity on the structure and corrosive properties of microarc oxidation (MAO) films on AZ31 magnesium alloy and explore the mechanism for modified anti-corrosion properties of irradiated films. Design/methodology/approach The energy deposited on the coating surface influences the remelting process of the MAO coatings significantly, which was closely related to the intensity of HIPIB; therefore, HIPIB with various intensities of 100-350 A/cm2, was selected to modify the MAO films on AZ31 magnesium alloy. The changes in film structure and phase structure of modified films were characterized by scanning electron microscopy and X-ray diffractometry (XRD) with CuKα, respectively. The corrosive behavior of the MAO films was featured with polarization curves and electrochemical impedance spectrum in 3.5 per cent NaCl solution on a PAR 2273 electrochemical workstation. Findings The results clearly show that a dense, continual and remelted layer with a few micrometers in thickness was obtained on the irradiated surface at 200 A/cm2, which are mainly responsible for the modified and optimal anti-corrosion property of MAO films by suppressing/retarding the process of the corrosive electrolyte infiltration into magnesium substrate surface. Originality/value The paper reveals that HIPIB irradiation could modify the corrosion resistance by producing a remelted compact layer on the MAO film surface at a suitable irradiation parameter and explored the modified mechanism of MAO films.

Investigation of the Microstructure and Bio-Corrosion Behaviour of Mg-Zn and Mg-Zn-Ca Alloys

2013 ◽  
Vol 765 ◽  
pp. 788-792 ◽  
Author(s):  
Yu Lu ◽  
Andrew Bradshaw ◽  
Yu Lung Chiu ◽  
Ian Jones
Keyword(s):  
Heat Treatment ◽  
Corrosion Rate ◽  
Magnesium Alloys ◽  
Biomedical Applications ◽  
Corrosion Behaviour ◽  
Essential Elements ◽  
Alloying Elements ◽  
Unique Combination ◽  
Corrosion Performance ◽  
Corrosion Properties

Biomedical applications of magnesium alloys have attracted increasing attention due to their unique combination of advantages. However, the poor corrosion resistance is an obstacle to magnesium alloys being used as biodegradable materials. As zinc (Zn) and calcium (Ca) are non-toxic and recognized as nutritionally essential elements in the human body, in this study Zn and Ca were selected as alloying elements to produce suitable bio-corrosion properties. The grain size was reduced significantly from 141.4 μm to 97.3 μm by adding Ca. The bio-corrosion performance of the two alloys (Mg-3Zn and Mg-3Zn-0.3Ca) was characterized using immersion tests in simulated body fluid at 37 °C. The alloys were dominated by pitting corrosion. Heat treatment was used to alter the microstructure and influence further the corrosion rate. The correlation between microstructure and bio-corrosion rate was evaluated, in the light of the alloying elements and the heat treatment employed.

scholarly journals Degradation of Sol-Gel Acrylic Coatings Based on Si and Zr Investigated Using Electrochemical Impedance, Infrared and X-Ray Photoelectron Spectroscopies

2021 ◽  
Vol 8 ◽  
Author(s):  
Peter Rodič ◽  
Sandrine Zanna ◽  
Ingrid Milošev ◽  
Philippe Marcus
Keyword(s):  
Corrosion Protection ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Ion Beam ◽  
Salt Spray ◽  
Sol Gel ◽  
Synthesis Process ◽  
Corrosion Properties ◽  
X Ray ◽  
Acrylic Coatings

This study aimed to synthesise and characterise two types of sol-gel acrylic coatings: one based on Si and the other based on Si and Zr. These coatings, which served as a barrier for corrosion protection of aluminium, were synthesised by sol-gel methodology using silicon precursors tetraethyl orthosilicate and organically modified silicon precursor 3-methacryloxypropyltrimethoxysilane, without and with the addition of zirconium(IV) n-propoxide chelated with methacrylic acid. The synthesis process was followed using real-time Fourier transform infrared spectroscopy, which confirmed the condensation reactions of Si–O–Si and Si–O–Zr networks, depending on the sol type. This was reflected in the composition of the coating as well, as shown by X-ray photoelectron spectroscopy. The coating topography, thickness and morphology were analysed using focused ion beam scanning electron microscopy. X-ray photoelectron spectroscopy was employed to follow the degradation of acrylic coatings upon immersion in sodium chloride solution. Corrosion properties, evaluated using electrochemical impedance spectroscopy in 0.1 M NaCl, confirmed high barrier protection of coated aluminium with acrylic coatings based on Si and even better for coating based on Si with Zr. The more durable corrosion protection of the latter was also confirmed by salt spray testing.

Electrochemical Impedance Characteristics of Sintered 7075 Aluminum Alloy Under Ssrt Condition

2013 ◽  
Vol 58 (2) ◽  
pp. 505-508 ◽  
Author(s):  
S. Sunada ◽  
N. Nunomura
Keyword(s):  
Aluminum Alloys ◽  
Complex Shape ◽  
Electrochemical Impedance ◽  
Ingot Metallurgy ◽  
View Point ◽  
Corrosion Properties ◽  
Electrochemical Tests ◽  
Impedance Characteristics ◽  
Polarization Test ◽  
Conventional Ingot

Powder metallurgy (P/M) process has the advantage of better formability to fabricate complex shape products without machining and welding. And recently this P/M process has been applied to the production of aluminum alloys. The P/M aluminum alloys thus produced also have received considerable interest because of their fine and homogeneous structure. Many papers have been published on the mechanical properties of the aluminum alloys produced by P/M process while there have been few on their corrosion properties from the view point of electrochemistry. In this experiment, therefore, two kinds of 7075 aluminum alloys prepared by the conventional ingot metallurgy (I/M) process and P/M process were used, I/M material is commercially available. and their corrosion behavior were investigated through the electrochemical tests such as potentiodynamic polarization test, slow rate strain tensile (SSRT) test and electrochemical impedance spectroscopy (EIS) measurement under SSRT test in the corrosion solution and the deionized water.

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