Pub Date : 2018-12-19DOI: 10.5772/INTECHOPEN.79789
I. Nakatsugawa, Y. Chino, H. Nakano
Water-activated magnesium batteries possess several favorable attributes for energy storage and lighting sources. In this chapter, a portable-sized magnesium battery which consisted of MnO 2 cathodes and magnesium alloy anodes, being activated by drops of water, was investigated. The anode and cathode potential as well as their electrochemical impedance under a constant current load was monitored to evaluate the effect of water content, cell stacking, and discharging cycles. It was revealed that the discharge behavior was initially controlled by the depletion of water, followed by the cease of cathode reac - tion and the accumulation of Mg(OH) 2 at anode. The problem of low anode efficiency caused by stacking cells was analyzed, and its countermeasure was proposed. Several approaches to improve the battery performance were also presented.
{"title":"Discharge Behavior of Water-Activated Magnesium Battery","authors":"I. Nakatsugawa, Y. Chino, H. Nakano","doi":"10.5772/INTECHOPEN.79789","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.79789","url":null,"abstract":"Water-activated magnesium batteries possess several favorable attributes for energy storage and lighting sources. In this chapter, a portable-sized magnesium battery which consisted of MnO 2 cathodes and magnesium alloy anodes, being activated by drops of water, was investigated. The anode and cathode potential as well as their electrochemical impedance under a constant current load was monitored to evaluate the effect of water content, cell stacking, and discharging cycles. It was revealed that the discharge behavior was initially controlled by the depletion of water, followed by the cease of cathode reac - tion and the accumulation of Mg(OH) 2 at anode. The problem of low anode efficiency caused by stacking cells was analyzed, and its countermeasure was proposed. Several approaches to improve the battery performance were also presented.","PeriodicalId":18118,"journal":{"name":"Magnesium Alloys - Selected Issue","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80190690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-19DOI: 10.5772/INTECHOPEN.79507
C. Chao
Oxygen sustains the lives of human a unique element. However, oxygen is unwanted and harmful when it is over tension to introduce oxygen-derived free radicals in the cells. Hydrogen and oxygen are both involved in the genesis of life that exists on Earth and metabolism in vivo, so it is not strange to exert a biological effect. Recently, scientists have found that hydrogen is an essential physiological regulatory function with antioxi- dant, anti-inflammatory, and antiapoptotic protective effects on cells. Using therapeutic hydrogen includes different delivery methods, such as inhalation of hydrogen gas, oral hydrogen water, and injection of hydrogen-saturated saline. In clinical applications, magnesium hydride hydrolysis instead of traditional metallic magnesium is effective in increasing the theoretical hydrogen storage capacity by two times. The hydrogen-water comes across as being an excellent choice to produce from magnesium hydride hydroly- sis on-demand because its antioxidant activity cannot store.
{"title":"Clinical Applications of Magnesium Hydride","authors":"C. Chao","doi":"10.5772/INTECHOPEN.79507","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.79507","url":null,"abstract":"Oxygen sustains the lives of human a unique element. However, oxygen is unwanted and harmful when it is over tension to introduce oxygen-derived free radicals in the cells. Hydrogen and oxygen are both involved in the genesis of life that exists on Earth and metabolism in vivo, so it is not strange to exert a biological effect. Recently, scientists have found that hydrogen is an essential physiological regulatory function with antioxi- dant, anti-inflammatory, and antiapoptotic protective effects on cells. Using therapeutic hydrogen includes different delivery methods, such as inhalation of hydrogen gas, oral hydrogen water, and injection of hydrogen-saturated saline. In clinical applications, magnesium hydride hydrolysis instead of traditional metallic magnesium is effective in increasing the theoretical hydrogen storage capacity by two times. The hydrogen-water comes across as being an excellent choice to produce from magnesium hydride hydroly- sis on-demand because its antioxidant activity cannot store.","PeriodicalId":18118,"journal":{"name":"Magnesium Alloys - Selected Issue","volume":"1555 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91457095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-11-05DOI: 10.5772/INTECHOPEN.79497
S. Fajardo, F. R. García-Galván, V. Barranco, Juan Carlos Galván, S. Batlle
In order to elucidate the corrosion mechanism of Magnesium (Mg), assess its corrosion rate and evaluate the viability of effective corrosion protection methods, a number of different and complementary techniques are required. Aqueous corrosion is, in nature, an electrochemical process and as such electrochemical methods represent a powerful tool for the study of Mg corrosion. In this chapter the main electrochemical techniques used to study the corrosion of Mg are reviewed along with other simple non-electrochemical methods such as weight loss and hydrogen evolution measurements. The electrochemical techniques covered in this review include conventional DC and AC electrochemical techniques and the latest advances in local electrochemical methods for the evaluation and characterization of Mg corrosion. Each technique presented will be discussed, and its major advantages and drawbacks for the study of Mg corrosion will be commented. Applications range from studies of influence of the impurities in catalytic activity of high purity Mg towards hydrogen evolution, the determination of corrosion rate for Mg and Mg alloys by electrochemical methods and electrochemical study of sol-gel films as pretreatment for Mg alloys.
{"title":"A Critical Review of the Application of Electrochemical Techniques for Studying Corrosion of Mg and Mg Alloys: Opportunities and Challenges","authors":"S. Fajardo, F. R. García-Galván, V. Barranco, Juan Carlos Galván, S. Batlle","doi":"10.5772/INTECHOPEN.79497","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.79497","url":null,"abstract":"In order to elucidate the corrosion mechanism of Magnesium (Mg), assess its corrosion rate and evaluate the viability of effective corrosion protection methods, a number of different and complementary techniques are required. Aqueous corrosion is, in nature, an electrochemical process and as such electrochemical methods represent a powerful tool for the study of Mg corrosion. In this chapter the main electrochemical techniques used to study the corrosion of Mg are reviewed along with other simple non-electrochemical methods such as weight loss and hydrogen evolution measurements. The electrochemical techniques covered in this review include conventional DC and AC electrochemical techniques and the latest advances in local electrochemical methods for the evaluation and characterization of Mg corrosion. Each technique presented will be discussed, and its major advantages and drawbacks for the study of Mg corrosion will be commented. Applications range from studies of influence of the impurities in catalytic activity of high purity Mg towards hydrogen evolution, the determination of corrosion rate for Mg and Mg alloys by electrochemical methods and electrochemical study of sol-gel films as pretreatment for Mg alloys.","PeriodicalId":18118,"journal":{"name":"Magnesium Alloys - Selected Issue","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90127553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-11-05DOI: 10.5772/INTECHOPEN.80291
A. Kiełbus
Magnesium alloys are widely used in aerospace and automotive industry due to their low density, good mechanical properties, and good castability. Their main disadvantage is low maximum working temperature (about 120°C for Mg-Al alloys). This led to the development of Mg-Al-RE or Mg-RE-Zr alloys, which can work up to 250°C. The chapter will relate to the sand cast and high pressure die cast magnesium alloys. Material for the research consisted of six magnesium casting alloys: AE44, AJ62, WE54, EV31A, and for comparison AZ91 and AM50. The influence of casting and heat treatment parameters on the microstructure and mechanical properties will be introduced. The relationship between the initial structure, casting parameters, phase composition, and mechanical properties in magnesium alloys will be presented.
{"title":"Microstructure and Properties of Casting Magnesium Alloys Designed to Work in Elevated Temperature","authors":"A. Kiełbus","doi":"10.5772/INTECHOPEN.80291","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.80291","url":null,"abstract":"Magnesium alloys are widely used in aerospace and automotive industry due to their low density, good mechanical properties, and good castability. Their main disadvantage is low maximum working temperature (about 120°C for Mg-Al alloys). This led to the development of Mg-Al-RE or Mg-RE-Zr alloys, which can work up to 250°C. The chapter will relate to the sand cast and high pressure die cast magnesium alloys. Material for the research consisted of six magnesium casting alloys: AE44, AJ62, WE54, EV31A, and for comparison AZ91 and AM50. The influence of casting and heat treatment parameters on the microstructure and mechanical properties will be introduced. The relationship between the initial structure, casting parameters, phase composition, and mechanical properties in magnesium alloys will be presented.","PeriodicalId":18118,"journal":{"name":"Magnesium Alloys - Selected Issue","volume":"73 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80053740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-11-05DOI: 10.5772/INTECHOPEN.79752
Z. Trojanová, Z. Drozd, P. Lukáč
Superplastic materials exhibit anomalous plasticity, achieving strain until several thousand per cent. The phenomenon of plasticity is limited on special microstructure, temperatures and strain rates. Magnesium and magnesium alloys are known as materials with limited plasticity. This is due to their hexagonal structure of these materials. Finding the superplasticity conditions has a crucial importance for applications of magnesium alloys. In this chapter, we will deal with the superplastic behaviour of AZ91, QE22, AE42 and EZ33 magnesium alloys. Materials were prepared by various techniques: thermomechanical treatments, equal channel angular pressing, hot extrusion, rolling, friction stirring and high-pressure torsion. Strain rate sensitivity and elongation to fracture were estimated at various temperatures. Mechanisms of superplastic flow are discussed. Grain boundary sliding and diffusional processes were depicted as the main mechanisms responsible for high plasticity of these alloys. On the other hand, cavitation at elevated temperatures deteriorates the superplastic properties.
{"title":"Superplastic Behaviour of Selected Magnesium Alloys","authors":"Z. Trojanová, Z. Drozd, P. Lukáč","doi":"10.5772/INTECHOPEN.79752","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.79752","url":null,"abstract":"Superplastic materials exhibit anomalous plasticity, achieving strain until several thousand per cent. The phenomenon of plasticity is limited on special microstructure, temperatures and strain rates. Magnesium and magnesium alloys are known as materials with limited plasticity. This is due to their hexagonal structure of these materials. Finding the superplasticity conditions has a crucial importance for applications of magnesium alloys. In this chapter, we will deal with the superplastic behaviour of AZ91, QE22, AE42 and EZ33 magnesium alloys. Materials were prepared by various techniques: thermomechanical treatments, equal channel angular pressing, hot extrusion, rolling, friction stirring and high-pressure torsion. Strain rate sensitivity and elongation to fracture were estimated at various temperatures. Mechanisms of superplastic flow are discussed. Grain boundary sliding and diffusional processes were depicted as the main mechanisms responsible for high plasticity of these alloys. On the other hand, cavitation at elevated temperatures deteriorates the superplastic properties.","PeriodicalId":18118,"journal":{"name":"Magnesium Alloys - Selected Issue","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83402988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-11-05DOI: 10.5772/INTECHOPEN.81761
T. Tański, M. Król
Magnesium is an element constituting 2.74% of the Earth’s crust. It occurs in most countries in the form of various compounds and minerals. The most common ores are dolomites (MgCO3·CaCO3) and magnesites (MgCO3). Another mineral used for the magnesium production is carnallite. Magnesium is also included in serpentine. Oceans are a rich source of magnesium, which contain approx. 0.13% of the metal in the salt solution as MgCl2 and MgSO4. In 1808, the electrolysis of molten salts allowed Humphrey Davy, an English chemist, to extract pure active metals for the first time, including magnesium [4–6].
{"title":"Introductory Chapter: Magnesium Alloys","authors":"T. Tański, M. Król","doi":"10.5772/INTECHOPEN.81761","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.81761","url":null,"abstract":"Magnesium is an element constituting 2.74% of the Earth’s crust. It occurs in most countries in the form of various compounds and minerals. The most common ores are dolomites (MgCO3·CaCO3) and magnesites (MgCO3). Another mineral used for the magnesium production is carnallite. Magnesium is also included in serpentine. Oceans are a rich source of magnesium, which contain approx. 0.13% of the metal in the salt solution as MgCl2 and MgSO4. In 1808, the electrolysis of molten salts allowed Humphrey Davy, an English chemist, to extract pure active metals for the first time, including magnesium [4–6].","PeriodicalId":18118,"journal":{"name":"Magnesium Alloys - Selected Issue","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88174161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-11-05DOI: 10.5772/INTECHOPEN.80083
R. Zeng, Zheng-Zheng Yin, Xiaobo Chen, Dao-kui Xu
Magnesium (Mg) alloys are susceptible to corrosion in aggressive environments. Corrosion of Mg alloys depends greatly on their composition and microstructure (grain size, the size, shape and distribution of second phases), post-processing and media. In most cases, localized corrosion, such as pitting corrosion and filiform corrosion, generally occurs due to microgalvanic corrosion between the intermetallic compounds and their neighboring α -Mg matrix. However, open literature reported that several corrosion mor- phologies, that is, intergranular corrosion (IGC) and exfoliation corrosion (EFC), cannot appear on Mg alloys. In this chapter, all typical corrosion modes of Mg alloys and influ - encing factors are introduced, including general corrosion, galvanic corrosion, pitting corrosion, filiform corrosion, IGC, EFC, stress corrosion cracking (SCC), corrosion fatigue (CF) and so on. The focus is laid on pitting corrosion and EFC. Corrosion mechanisms of Mg alloys are also discussed.
{"title":"Corrosion Types of Magnesium Alloys","authors":"R. Zeng, Zheng-Zheng Yin, Xiaobo Chen, Dao-kui Xu","doi":"10.5772/INTECHOPEN.80083","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.80083","url":null,"abstract":"Magnesium (Mg) alloys are susceptible to corrosion in aggressive environments. Corrosion of Mg alloys depends greatly on their composition and microstructure (grain size, the size, shape and distribution of second phases), post-processing and media. In most cases, localized corrosion, such as pitting corrosion and filiform corrosion, generally occurs due to microgalvanic corrosion between the intermetallic compounds and their neighboring α -Mg matrix. However, open literature reported that several corrosion mor- phologies, that is, intergranular corrosion (IGC) and exfoliation corrosion (EFC), cannot appear on Mg alloys. In this chapter, all typical corrosion modes of Mg alloys and influ - encing factors are introduced, including general corrosion, galvanic corrosion, pitting corrosion, filiform corrosion, IGC, EFC, stress corrosion cracking (SCC), corrosion fatigue (CF) and so on. The focus is laid on pitting corrosion and EFC. Corrosion mechanisms of Mg alloys are also discussed.","PeriodicalId":18118,"journal":{"name":"Magnesium Alloys - Selected Issue","volume":"68 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89878000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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