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Friedrich · MordikeMagnesium Technology
Horst E. Friedrich · Barry L. Mordike
Magnesium TechnologyMetallurgy, Design Data, Applications
With 590 Figures
3
Professor Dr.-Ing. Horst E. FriedrichInstitut für Fahrzeugkonzepte (FK)Deutsches Zentrum für Luft- und Raumfahrt (DLR) e.V.in der Helmholtz-GemeinschaftPfaffenwaldring 38–4070569 StuttgartGermanye-mail: [email protected]
Professor Dr. Barry L. MordikeInstitut für Werkstoffkunde und WerkstofftechnikTU ClausthalAgricolastrasse 638678 Clausthal-ZellerfeldGermany e-mail: [email protected]
Library of Congress Control Number 2005931991
ISBN-10 3-540-20599-3 Springer Berlin Heidelberg New YorkISBN-13 978-3-540-20599-9 Springer Berlin Heidelberg New York
This work is subject to copyright.All rights are reserved,whether the whole or part of the material is concerned,specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction onmicrofilms or in any other ways,and storage in data banks.Duplication of this publication or parts thereof is onlypermitted under the provisions of the German Copyright Law of September 9, 1965, in its current version, andpermission for use must always be obtained from Springer-Verlag.Violations are liable to prosecution under theGerman Copyright Law.
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Preface/Foreword
Magnesium was discovered and isolated as a chemical element in 1808 by SirHumphrey Davy. The problem with its isolation was associated with its reactiv-ity, which has haunted all those interested in using magnesium as components.The applications today must also consider the problems of corrosion. If we con-sider other properties e.g. elastic rigidity we find that the elastic constants are sig-nificantly lower than those of other metals. The yield strength or ultimate tensilestrength is also poorer than most constructional metals.
The significant event at the beginning of the twentieth century was aviationand this changed the rules – it was the specific yield strength which was impor-tant and indeed much work was undertaken in the two wars to develop magne-sium alloys for aviation. Magnesium had come of age and was used extensivelyin military aircraft during the Second World War. Thereafter, there was a slumpin its use and apart from isolated applications was unable to compete with othermetals, both from an economic and also technological standpoint.
In the nineteen-nineties a concentrated effort was made to solve many of theproblems, which limited the widespread application of magnesium alloys. Thiseffort was essentially global with producers and car manufacturers uniting sothat magnesium becomes recognised as a structural material. One group wasUSA and Canada, another was Australia with CAST, Israel, Norsk Hydro, MEL andGermany. In this book we have authors covering all aspects of magnesium tech-nology. For the first time in 50 years we are able to show which advances in com-ponent development have been made possible since the tome by Emley of MEL.The authors come from Germany, USA, Norway, Canada, Israel, Switzerland andthe UK and have covered the following topics on a chapter or sub-chapter basis.
There have not been many books on magnesium. The first was Beck’s “Magnesium und seine Legierungen”, published in the 1930’s, which was hur-riedly translated into English. This was followed 25 years later by Emley’s book,Principles of “Magnesium Technology”. This was a comprehensive revue of thestate of the art. Since that time there has been the ASM Handbook which pro-vided a useful collation of the properties of magnesium alloys but did not attemptto update Emley.
There are nine chapters in this book. The first chapter covers the history un-til 1945 and also from 1945 to about 1990. The second chapter covers an exten-sive survey of 30 pages of various production technologies of magnesium. Thisis followed by a detailed presentation of the physical metallurgy, physical and me-chanical constants, deformation behaviour, strengthening mechanisms, classifi-
CHAPTER 1
cation of alloys, binary and higher phase diagrams, various MEL alloys and highly creep resistant alloys. Chapter 4 is devoted to melting, alloying and refin-ing. Chapter 5 is a contribution by several authors of 70 pages to a detailed de-scription of present day magnesium casting alloys. Chapter 6 covers the tech-nology of magnesium and its alloys. This chapter of 200 pages discusses manyaspects e.g. sand casting, casting defects, inspection, identification and elimina-tion of defects. This is followed by a discussion of die casting, also squeeze cast-ing and semi-solid casting with their associated properties. Rolling of magne-sium and sheet metal forming is a recent important extension to magnesiumtechnology. Extrusion is also discussed with alloy developments and novel ex-trusion methods. An important topic in this chapter is magnesium matrix com-posites. Joining and welding processes are also covered in this chapter. Alterna-tive processes to welding, such as adhesive bonding technology, clinching,riveting, direct screwing, folding, hybrid joining are relatively new methods ofjoining magnesium. Machining of reinforced and un-reinforced magnesium alloys concludes this chapter.
Chapter 7 is dedicated to corrosion and surface protection and represents achapter in which significant advances have been made and where some problemshave been eliminated. Chapter 8 shows examples of automobile applications inEurope and North America together with concepts of life cycle inventory of ve-hicles, other applications such as hand tools, sports equipment, electronic equip-ment and aerospace. Barriers to magnesium are also discussed. In chapter 9 theproblem of setting up a secondary recycling strategy for magnesium is discussed.
This book for the first time shows a wide spectrum of applications. Obviously,the automobile applications are particularly important as they could guaranteethat a sufficient volume of magnesium is produced; ensuring that unit prices arelow. The price competition is keen and there is still much to be achieved withwrought products, in particular.
Significant advances have been made in corrosion protection, joining tech-nologies and recycling.
Horst E. Friedrich Barry L. Mordike
VI Preface/Foreword
Contents VII
Dr. Horst E. Friedrich
Prof. Dr. H. E. Friedrich studied engineering at the Technical University ofMunich. After working in the engineering and consultancy sectors, he took up asenior management position in the aeronautical industry in 1986. He was res-ponsible for new methods of construction and new materials, aircraft enginesand optimising product development times. In 1996, Prof. Friedrich joined Volks-wagen AG in Wolfsburg as head of vehicle research, where at last he was head ofGroup research for materials technology and vehicle concepts. He specialised ininnovative materials and construction methods, and concept vehicles for futurevehicle specifications.
Since March 2004 he is director of the Institute of Vehicle Concepts at the Ger-man Aerospace Center in Stuttgart and professor at the University of Stuttgart.The research fields are Alternative Power Trains and Energy Conversion as wellas Light Weight Design and Hybrid Construction methods.
Prof. Dr. Friedrich worked as Director of the Board of the International Magnesium Association (IMA) and has a lectureship at the Technical Universityof Berlin for materials and design in the transportation industry.
Prof. Dr Barry L. Mordike
Barry Mordike studied Physical Metallurgy at Birmingham University and com-pleted his studies with BSc(Hons) Class1 in 1956. He then undertook research forhis PhD in the Cavendish Laboratory, Department of Physics, University ofCambridge, completing his PhD in Summer 1959. He then continued research inthe Institut für Metallphysik, Universität Göttingen as ‘Wissenschaftlicher Assis-tent’ to Prof. Peter Haasen. In September 1966 he took up a post as Senior Lec-turer (C4 Professur) in the Department of Metallurgy, University of Liverpool,where he stayed until the end of1976.In Dec 1976 he was appointed to the newlycreated Chair of Materials Engineering and Technology at the Technical Univer-sity of Clausthal. He remained at Clausthal until he became Emeritus Professorin October 1999.
Apart from his academic pursuits he created in 1989 a technology transfercompany, Zentrum für Funktionswerkstoffe g.G.m.b.H( Clausthal) with the aidof Government funding. This enabled projects to be completed where industrialcompetence and confidentiality were necessary. In 2002 Prof.V. Neubert took overfrom him as General Manager.
Initially, his research interests concentrated on fundamental problems such asdeformation processes, initiation of fatigue, crystal growth, strengthening mech-anisms in metals. He changed his emphasis and developed interests in more applied research. Prior to going to Clausthal he started to work on magnesiumalloys (1972), some aspects being supported by MEL (Elektron), Powder Metal-
lurgy (1973) and Laser Technology (1976).At Clausthal, he rapidly built up a con-siderable research potential and covered a wide range of subjects.
The period 1976 to 1999 will be remembered for its contribution to develop-ing Laser Treatment of Materials, Magnesium 1972 – present day, Powder Metal-lurgy and Composite Materials, Surface Engineering, in particular, Plasma Immersion Technology.
VIII Preface/Foreword
List of Contributors
Eli AghionDepartment of Materials Engineering, Ben Gurion University of the Negev,P.O.B. 653, Beer Sheva 84105, Israele-mail: [email protected]
Terje Kr. AuneAdvanced Magnesium Technologies Ltd, Level 9, 303 Coronation Drive, Milton,Queensland 4064, Australia
Robert E. Brown226 Deer Trace, Prattville, Alabama 36067, USAe-mail: [email protected]
Dieter BrungsEversberg, Ober den Eschen 9, 59872 Meschede, Germany
Bernard ClossetModal Technologies Inc., 8 Chemin de l’Ancien-Tir, 1252 Meinier, Switzerlande-Mail: [email protected]
Gerald Cole25800 Romany Way, Franklin, MI 48025-1197, USAe-mail: [email protected]
Günter H. DeinzerEntwicklung/Werkstoffe AUDI Ingolstadt, Germanye-mail: [email protected]
Berend DenkenaInstitut für Fertigungstechnik und Werkzeugmaschinen,Produktionstechnisches Zentrum, Universität Hannover, Schönebecker Allee 2,30823 Garbsen, Germanye-mail: [email protected]
CHAPTER 1
Hajo DieringaGKSS-Forschungszentrum Geesthacht Gmbh, Institut für Werkstoffforschung,Max-Planck-Straße 1, 21502 Geesthacht, Germanye-mail: [email protected]
Dan EliezerDepartment of Materials Engineering, Ben Gurion University of the Negev,P.O.B. 653, Beer Sheva 84105, Israele-mail: [email protected]
Steve Ericksone-mail: [email protected]
Horst E. FriedrichInstitut für Fahrzeugkonzepte (FK), Deutsches Zentrum für Luft- und Raumfahrt (DLR) e.V. in der Helmholtz-Gemeinschaft, Pfaffenwaldring 38-40,70569 Stuttgart, Germanye-mail: [email protected]
Francis H. Froes University of Idaho, Institute for Materials and Advanced Processes,College of Engineering, McClure Building, Room 437, Moscow,Idaho 83844-3026, USAe-mail: [email protected]
Gilad GolubEnvironmental Services Co. Ltd, Ramat Hovav, P.O. Box 5743, Beer Sheva 84156,Israel
Kurt HarbodtReiherstraße 44, 50997 Köln, Germanye-mail: [email protected]
Otto-Diedrich HennemannFraunhofer Institut, Fertigungstechnik und angewandte Materialforschung,Wiener Straße 12, 28359 Bremen, Germanye-mail: [email protected]
Jim Hillis1027 Riverview Ranch Dr., Brazoria, TX 77422, USAe-Mail: [email protected]
Norbert HortGKSS-Forschungszentrum Geesthacht Gmbh, Institut für Werkstoffforschung,Max-Planck-Straße 1, 21502 Geesthacht, Germanye-mail: [email protected]
X List of Contributors
Peter JuchmannSalzgitter Magnesium-Technologie AG, Eisenhüttenstr. 99, 38239 Salzgitter,Germanye-mail: [email protected]
Karl Ulrich KainerGKSS-Forschungszentrum Geesthacht Gmbh, Institut für Werkstoffforschung,Max-Planck-Straße 1, 21502 Geesthacht, Germanye-mail: [email protected]
Catrin KammerMETALL-Fachzeitschrift für Metallurgie, Kielsche Str. 43B, 38642 Goslar,Germanye-mail: [email protected]
Helmut KaufmannARC, Leichtmetallkompetenzzentrum Ranshofen GmbH, Postfach 26,5282 Ranshofen, Austriae-mail: [email protected]
John F. King19, Brookside Crescent, Greenmount, Bury, BL8 4BG, United Kingdome-mail: [email protected]
Simon KleinerEMPA, Feuerwerkerstr. 39, 3602 Thun, Switzerlande-mail: [email protected]
Sanday Thakar KumarSingapore Institute of Manufacturing Technology, Forming Technology Group,71, Nanyang Drive, Singapore 638075e-mail: thankur@SIM Tech.a-star.edu.sg
Peter KurzeAHC-Oberflächentechnik GmbH & Co. KG OGH, Postfach 00 21 49,50151 Kerpen, Germanye-mail: [email protected]
Pavel LukácDepartment of Metalphysics, Faculty of Mathematics and Physics,Charles University, Ke Karlovu 5, 12116 Praha 2, Czechiae-mail: [email protected]
Andreas MertzAm Stockfeld 24, 66539 Neunkirchen, Germanye-mail: [email protected]
List of Contributors XI
Gerson MeschutWilhelm Böllhof GmbH & Co. KG, Archimedesstraße, 33649 Bielefeld,Germanye-mail: [email protected]
Barry L. MordikeInstitut für Werkstoffkunde und Werkstofftechnik, TU Clausthal,Agricolastraße 6, 38678 Clausthal-Zellerfeld, Germanye-mail: [email protected]
Mihriban PekguleryuzMcGill University, Department of Mining and Mettallurgical Engineering,3610 University Street, Monreal, QC H3A 2B2, Canadae-mail: [email protected]
Christian PodolskyPfalzstr.10, 30173 Hannover, Germany
Michael RethmeierVolkswagen AG, Wolfsburg, Germanye-mail: [email protected]
Soenke SchumannVolkswagen AG, Konzernforschung, Werkstofftechnik/Metalle, Brieffach 1511,38436 Wolfsburg, Germanye-mail: [email protected]
Hans Kurt TönshoffUniversität Hannover Institute of Production Engineering and Machine Tools(IFW), Schlosswender Straße 5, 30159 Hannover, Germanye-mail: toenshoff@ ifw.uni-hannover.de
Håkon WestengenNorsk Hydro ASA, Research Centre Porsgrunn, Forskingsparken Heroya,3907 Porsgrunn, Norwaye-mail: [email protected]
Jens WinklerContinental AG, Jädekamp 30, 30419 Hannover, Germanye-mail: [email protected]
XII List of Contributors
Contents
1 History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 History until 1945Kurt Harbodt . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1.1 Asia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1.2 Australia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.1.3 Europe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.1.4 North America . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.2 History Since 1945Robert E. Brown . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.2.1 Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121.2.2 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
2 Production Technologies of MagnesiumGilad Golub, Eli Aghion . . . . . . . . . . . . . . . . . . . . . . . 29
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
2.2 Raw Materials for Magnesium Production . . . . . . . . . . . . . 30
2.2.1 Magnesite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312.2.2 Dolomite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312.2.3 Bischofite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312.2.4 Carnallite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312.2.5 Serpentine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322.2.6 Sea Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
2.3 Electrochemical Methods . . . . . . . . . . . . . . . . . . . . . 33
2.3.1 Preparation of Magnesium Chloride Salts from Natural Raw Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
2.3.2 Drying Magnesium Chloride Salts . . . . . . . . . . . . . . . . . 352.3.3 Electrolysis of Magnesium Salts . . . . . . . . . . . . . . . . . . 362.3.3.1 Type of Electrolytes for Electrolysis . . . . . . . . . . . . . . . . 362.3.3.2 Thermal Balance of the Electrolysis Cell . . . . . . . . . . . . . . 372.3.3.3 Increasing the Magnesium Output by Means of Artificial Cooling 39
CHAPTER 1
2.3.4 Types of Electrodes in the Electrolysis Cells . . . . . . . . . . . . 392.3.5 Structure of the Electrolysis Cells . . . . . . . . . . . . . . . . . 412.3.6 Operation of Electrolysis Cell . . . . . . . . . . . . . . . . . . . . 422.3.7 Refining Raw Magnesium Produced by Electrochemical Methods 432.3.8 Industrial Methods for Electrochemical Production . . . . . . . 442.3.8.1 DSM and Russian Process . . . . . . . . . . . . . . . . . . . . . 442.3.8.2 The Dow Process . . . . . . . . . . . . . . . . . . . . . . . . . . 462.3.8.3 The MagCorp (now US Mag) Process . . . . . . . . . . . . . . . 472.3.8.4 The Hydro Magnesium Process . . . . . . . . . . . . . . . . . . 472.3.8.5 The Magnola Process . . . . . . . . . . . . . . . . . . . . . . . . 492.3.8.6 The AMC Process . . . . . . . . . . . . . . . . . . . . . . . . . . 50
2.4 Thermal Reduction Methods . . . . . . . . . . . . . . . . . . . . 52
2.4.1 Preparation of Raw Material and Thermal Reduction Method . . 522.4.2 Industrial Methods with Thermal Reduction . . . . . . . . . . . 522.4.2.1 Silicothermic Processes . . . . . . . . . . . . . . . . . . . . . . . 522.4.2.2 Aluminothermic Processes . . . . . . . . . . . . . . . . . . . . . 562.4.2.3 Carbothermic Process . . . . . . . . . . . . . . . . . . . . . . . 572.4.3 Collection and Refining the Raw Magnesium Produced by
Thermal Reduction . . . . . . . . . . . . . . . . . . . . . . . . . 58
2.5 Advantages and Disadvantages of Electrolytic Production Versus Thermal Reduction Methods . . . . . . . . . . . . . . . . 59
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
3 Physical MetallurgyBarry L. Mordike, Pavel Lukac . . . . . . . . . . . . . . . . . . . 63
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
3.2 Properties of Pure Magnesium . . . . . . . . . . . . . . . . . . . 63
3.2.1 Atomic Properties . . . . . . . . . . . . . . . . . . . . . . . . . . 633.2.2 Electron States . . . . . . . . . . . . . . . . . . . . . . . . . . . . 643.2.3 Lattice Parameters . . . . . . . . . . . . . . . . . . . . . . . . . 643.2.4 Thermal Expansion . . . . . . . . . . . . . . . . . . . . . . . . . 653.2.5 Density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 653.2.6 Thermodynamic Properties . . . . . . . . . . . . . . . . . . . . 653.2.7 Diffusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 653.2.8 Thermal Conduction . . . . . . . . . . . . . . . . . . . . . . . . 663.2.9 Elastic Moduli . . . . . . . . . . . . . . . . . . . . . . . . . . . . 683.2.10 Damping Capacity . . . . . . . . . . . . . . . . . . . . . . . . . 683.2.11 Deformation Behavior . . . . . . . . . . . . . . . . . . . . . . . 743.2.12 Strengthening Mechanisms . . . . . . . . . . . . . . . . . . . . . 753.2.12.1 Dislocation Strengthening . . . . . . . . . . . . . . . . . . . . . 763.2.12.2 Solid Solution Hardening . . . . . . . . . . . . . . . . . . . . . . 763.2.12.3 Precipitation Strengthening . . . . . . . . . . . . . . . . . . . . 77
XIV Contents
3.2.12.4 Dispersion Strengthening . . . . . . . . . . . . . . . . . . . . . . 783.2.12.5 Strengthening by Grain Size Refinement . . . . . . . . . . . . . . 78
3.3 Magnesium Alloys . . . . . . . . . . . . . . . . . . . . . . . . . . 79
3.3.1 Common Alloying Elements . . . . . . . . . . . . . . . . . . . . 803.3.1.1 Aluminum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 803.3.1.2 Calcium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 803.3.1.3 Lithium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 803.3.1.4 Manganese . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 813.3.1.5 Rare Earths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 813.3.1.6 Silicon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 813.3.1.7 Silver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 813.3.1.8 Thorium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 813.3.1.9 Yttrium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 813.3.1.10 Zinc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 813.3.1.11 Zirconium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 813.3.2 Elements Used for Manufacturing Purposes or Impurities . . . . 823.3.2.1 Beryllium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 823.3.2.2 Copper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 823.3.2.3 Iron . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 823.3.2.4 Nickel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 823.3.2.5 Tin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 823.3.3 Classification of Alloys . . . . . . . . . . . . . . . . . . . . . . . 82
3.4 Phase Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
3.4.1 Conventional Alloys . . . . . . . . . . . . . . . . . . . . . . . . . 843.4.1.1 Magnesium-Aluminum . . . . . . . . . . . . . . . . . . . . . . . 843.4.1.2 Magnesium-Zinc . . . . . . . . . . . . . . . . . . . . . . . . . . 843.4.1.3 Magnesium-Manganese . . . . . . . . . . . . . . . . . . . . . . . 853.4.1.4 Super Light Weight Alloys . . . . . . . . . . . . . . . . . . . . . . 863.4.1.5 High Performance Alloys . . . . . . . . . . . . . . . . . . . . . . 873.4.1.6 Magnesium-Scandium . . . . . . . . . . . . . . . . . . . . . . . 883.4.1.7 Magnesium-Zirconium . . . . . . . . . . . . . . . . . . . . . . . 893.4.2 Higher Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
3.5 Commercial Alloy Systems . . . . . . . . . . . . . . . . . . . . . 92
3.5.1 Magnesium Die Casting Alloys (Zirconium Free) . . . . . . . . . 933.5.2 Permanent Mould, Sand and Investment Casting Alloys . . . . . 943.5.2.1 Magnesium-Zinc-Zirconium . . . . . . . . . . . . . . . . . . . . 943.5.2.2 Magnesium-Rare Earth-Zinc-Zirconium (ZK61 and ZK62) . . . 943.5.2.3 Magnesium-Silver . . . . . . . . . . . . . . . . . . . . . . . . . . 963.5.2.4 Magnesium-Yttrium Alloys . . . . . . . . . . . . . . . . . . . . . 963.5.3 Further Development . . . . . . . . . . . . . . . . . . . . . . . . 963.5.4 Highly Creep Resistant Alloys . . . . . . . . . . . . . . . . . . . 97
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Contents XV
4 Melting, Alloying and Refining . . . . . . . . . . . . . . . . . . . 109
4.1 Zirconium-Free AlloysMihriban Pekguleryuz . . . . . . . . . . . . . . . . . . . . . . . . 109
4.1.1 Mg-Al, Mg-Al-Zn, and Mg-Al-Si Alloys . . . . . . . . . . . . . . 1094.1.1.1 Flux Melting and Refining . . . . . . . . . . . . . . . . . . . . . 1094.1.1.2 Fluxless Melting, and Alloying (the use of Cover gases) . . . . . 1134.1.1.3 Alloying of Mg with Al, Zn, Si . . . . . . . . . . . . . . . . . . . . 1154.1.1.4 Manganese . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1164.1.1.5 Beryllium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1194.1.1.6 Silicon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1214.1.2 Mg-Al-(Rare-Earth) Alloys . . . . . . . . . . . . . . . . . . . . . 1214.1.3 Mg-Al-(Alkaline Earth) Alloys . . . . . . . . . . . . . . . . . . . 1224.1.3.1 Calcium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1234.1.3.2 Strontium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1234.1.4 Mg-Li Alloys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
4.2 Alloys Containing ZirconiumJohn F. King . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
4.2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1284.2.2 Mechanism of Grain Refinement by Zirconium . . . . . . . . . . 1284.2.3 Effect of Other Alloying Elements . . . . . . . . . . . . . . . . . 1314.2.3.1 Incompatible Elements . . . . . . . . . . . . . . . . . . . . . . . 1314.2.3.2 Compatible Alloy Systems . . . . . . . . . . . . . . . . . . . . . 1324.2.4 Methods of Introducing Zirconium . . . . . . . . . . . . . . . . 1334.2.4.1 Products Available . . . . . . . . . . . . . . . . . . . . . . . . . . 1334.2.4.2 Basic Principles of Zr Grain Refinement . . . . . . . . . . . . . . 1334.2.4.3 Zirconium Grain Refining in Fluxed Melts . . . . . . . . . . . . . 1354.2.4.4 Zirconium Grain Refining in Flux-Free Melts . . . . . . . . . . . 1374.2.4.5 Methods of Assessing Grain Refinement . . . . . . . . . . . . . . 1384.2.5 Melting, Alloying Procedures for Other Elements . . . . . . . . . 139
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
5 Magnesium Casting Alloys . . . . . . . . . . . . . . . . . . . . . 145
5.1 Casting AlloysHåkon Westengen, Terje Kr. Aune . . . . . . . . . . . . . . . . . . 145
5.1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1455.1.2 Alloying Principles . . . . . . . . . . . . . . . . . . . . . . . . . 1465.1.2.1 Properties of Pure Magnesium . . . . . . . . . . . . . . . . . . . 1465.1.2.2 Alloy Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . 1465.1.2.3 Alloying Elements and Their Influence . . . . . . . . . . . . . . 1495.1.3 Casting Methods . . . . . . . . . . . . . . . . . . . . . . . . . . 1625.1.4 Alloys for Diecasting . . . . . . . . . . . . . . . . . . . . . . . . 1665.1.4.1 Compositions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1665.1.4.2 Microstructures (Hydro Magnesium) . . . . . . . . . . . . . . . 167
XVI Contents
5.1.4.3 Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1715.1.5 Alloys for Sand Casting . . . . . . . . . . . . . . . . . . . . . . . 1985.1.5.1 Compositions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1985.1.5.2 Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
5.2 Wrought AlloysCatrin Kammer . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
5.2.1 Magnesium – Aluminum . . . . . . . . . . . . . . . . . . . . . . 2085.2.2 Magnesium – Manganese (M-alloys) . . . . . . . . . . . . . . . . 2105.2.3 Magnesium – Aluminum – Zinc (AZ-alloys) . . . . . . . . . . . . 2105.2.4 Magnesium – Zinc – Zirconium (ZK-Alloys) . . . . . . . . . . . 2125.2.5 Magnesium – Zinc – Rare Earth (ZE-Alloys) . . . . . . . . . . . 2125.2.6 Magnesium – Yttrium – Rare Earth (WE-Alloys) . . . . . . . . . 2125.2.7 Magnesium – Thorium, Zirconium or Manganese
(HK- and HM-Alloys) . . . . . . . . . . . . . . . . . . . . . . . . 2135.2.8 Magnesium – Lithium – Alloys (LA-Alloys) . . . . . . . . . . . . 2135.2.9 Other Wrought Alloys . . . . . . . . . . . . . . . . . . . . . . . . 214
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
6 Technology of Magnesium and Magnesium Alloys . . . . . . . . 219
6.1 Casting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219
6.1.1 Sand CastingJohn F. King . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219
6.1.1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2196.1.1.2 Sand Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2206.1.1.3 Design of Running Systems . . . . . . . . . . . . . . . . . . . . . 2236.1.1.4 Mould Preparation and Assembly . . . . . . . . . . . . . . . . . 2266.1.1.5 Identification and Elimination of Defects . . . . . . . . . . . . . 2286.1.1.6 Sand Casting Techniques . . . . . . . . . . . . . . . . . . . . . . 2296.1.1.7 Heat Treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . 2316.1.1.8 Inspection of Castings . . . . . . . . . . . . . . . . . . . . . . . 232
6.1.2 Die CastingDieter Brungs, Andreas Mertz . . . . . . . . . . . . . . . . . . . . 234
6.1.2.1 Die Casting Process for Magnesium . . . . . . . . . . . . . . . . 2346.1.2.2 Design Guidelines for Magnesium Die Castings . . . . . . . . . . 2476.1.2.3 Properties of Magnesium Die Castings . . . . . . . . . . . . . . 2526.1.2.4 Environmental Impact . . . . . . . . . . . . . . . . . . . . . . . 257
6.1.3 Squeeze Casting, Thixocasting and RheocastingHelmut Kaufmann, Simon Kleiner . . . . . . . . . . . . . . . . . 258
6.1.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2586.1.3.2 Squeeze Casting . . . . . . . . . . . . . . . . . . . . . . . . . . . 2596.1.3.3 Semi-Solid Casting . . . . . . . . . . . . . . . . . . . . . . . . . 261
6.2 Forming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269
Contents XVII
6.2.1 Rolling and Shut FormingPeter Juchmann . . . . . . . . . . . . . . . . . . . . . . . . . . . 269
6.2.1.1 Situation and Potential of Magnesium Sheet . . . . . . . . . . . 2696.2.1.2 Forming of Magnesium and Magnesium Alloys . . . . . . . . . . 2726.2.1.3 Magnesium Rolling . . . . . . . . . . . . . . . . . . . . . . . . . 2746.2.1.4 Magnesium Sheet . . . . . . . . . . . . . . . . . . . . . . . . . . 2766.2.1.5 Sheet Metal Forming . . . . . . . . . . . . . . . . . . . . . . . . 2786.2.1.6 Prototyping and Application Perspectives . . . . . . . . . . . . . 2846.2.1.7 Concluding Remarks and Outlook . . . . . . . . . . . . . . . . . 287
6.2.2 Extrusion, ForgingBernard Closset . . . . . . . . . . . . . . . . . . . . . . . . . . . 289
6.2.2.1 Production of Cast Stock . . . . . . . . . . . . . . . . . . . . . . 2896.2.2.2 Extrusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2946.2.2.3 Magnesium Extrusion Fundamentals . . . . . . . . . . . . . . . 2996.2.2.4 Alloy Developments . . . . . . . . . . . . . . . . . . . . . . . . . 3106.2.2.5 Novel Extrusion Methods . . . . . . . . . . . . . . . . . . . . . . 3126.2.2.6 Bending of Magnesium Extrusions . . . . . . . . . . . . . . . . . 314
6.3 Magnesium Matrix CompositesNorbert Hort, Hajo Dieringa, Sanday T. Kumar, Karl Ulrich Kainer 315
6.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3156.3.2 Reinforcements . . . . . . . . . . . . . . . . . . . . . . . . . . . 3196.3.2.1 Particle-Reinforcement . . . . . . . . . . . . . . . . . . . . . . . 3206.3.2.2 Fibre-Reinforcement . . . . . . . . . . . . . . . . . . . . . . . . 3216.3.2.3 Whisker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3226.3.2.4 Hybrids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3226.3.3 Manufacturing . . . . . . . . . . . . . . . . . . . . . . . . . . . 3236.3.3.1 Ingot Metallurgy . . . . . . . . . . . . . . . . . . . . . . . . . . 3236.3.3.2 Powder Metallurgy . . . . . . . . . . . . . . . . . . . . . . . . . 3266.3.4 Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3296.3.5 Alloys and Composites . . . . . . . . . . . . . . . . . . . . . . . 3316.3.6 Machining and Recycling . . . . . . . . . . . . . . . . . . . . . . 3336.3.7 Corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334
6.4 Joining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335
6.4.1 Motivation and RequirementsGerson Meschut . . . . . . . . . . . . . . . . . . . . . . . . . . . 335
6.4.2 Joining MagnesiumGünter H. Deinzer . . . . . . . . . . . . . . . . . . . . . . . . . . 336
6.4.3 Welding and Other Thermal ProcessesGünter H. Deinzer, Michael Rethmeier . . . . . . . . . . . . . . . 349
6.4.3.1 Weldability of Magnesium Alloys . . . . . . . . . . . . . . . . . 3496.4.3.2 TIG Welding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3496.4.3.3 MIG Welding . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3496.4.3.4 Laser-Beam Welding . . . . . . . . . . . . . . . . . . . . . . . . 356
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6.4.3.5 Electron-Beam Welding . . . . . . . . . . . . . . . . . . . . . . . 3596.4.3.6 Friction Welding . . . . . . . . . . . . . . . . . . . . . . . . . . 3596.4.3.7 Brazing and Soldering . . . . . . . . . . . . . . . . . . . . . . . 364
6.4.4 Adhesive BondingOtto-Diedrich Hennemann . . . . . . . . . . . . . . . . . . . . . 365
6.4.4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3656.4.4.2 Adhesives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3676.4.4.3 Pre-treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3696.4.4.4 Adhesive Bonding Technology . . . . . . . . . . . . . . . . . . . 3716.4.4.5 Strength and Testing . . . . . . . . . . . . . . . . . . . . . . . . 3726.4.4.6 Development Tendencies . . . . . . . . . . . . . . . . . . . . . . 373
6.4.5 Mechanical and Hybrid JoiningGerson Meschut . . . . . . . . . . . . . . . . . . . . . . . . . . . 374
6.4.5.1 Clinching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3746.4.5.2 Riveting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3776.4.5.3 Direct Screwing (Self-piercing/-Tapping) . . . . . . . . . . . . . 3856.4.5.4 Folding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3926.4.5.5 Hybrid Joining . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3946.4.5.6 Conclusion and OutView . . . . . . . . . . . . . . . . . . . . . . 396
6.5 MachiningHans Kurt Tönshoff, Berend Denkena, Jens Winkler,Christian Podolsky . . . . . . . . . . . . . . . . . . . . . . . . . 398
6.5.1 Machining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3986.5.1.1 Machining of not Reinforced Magnesium Alloys . . . . . . . . . 3996.5.1.2 Machining of Reinforced Mg Alloys . . . . . . . . . . . . . . . . 4066.5.1.3 Cooling Lubricants . . . . . . . . . . . . . . . . . . . . . . . . . 4096.5.2 Burnishing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 418
7 Corrosion and Surface Protections . . . . . . . . . . . . . . . . 431
7.1 Surface Treatments and ProtectionPeter Kurze . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431
7.1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4317.1.2 Passivation Properties of Magnesium-Based Materials in Air . . 4327.1.2.1 Resistance of the Passivated Layer to Chemicals . . . . . . . . . . 4337.1.3 Surface Treatment of Magnesium-Based Materials . . . . . . . . 4337.1.3.1 Principles and Prerequisites for Optimum Surface Protection . . 4337.1.3.2 Preliminary Treatment . . . . . . . . . . . . . . . . . . . . . . . 4377.1.3.3 Conversion Coatings Provided by Electroless Electrochemical
Surface Treatment . . . . . . . . . . . . . . . . . . . . . . . . . . 4397.1.3.4 Conversion Coatings Provided by Anodic Oxidation . . . . . . . 4507.1.3.5 Conversion Coatings Provided by Anodic Plasma-Chemical
Reaction in the Electrolyte . . . . . . . . . . . . . . . . . . . . . 455
Contents XIX
7.1.3.6 Galvanic-deposit coatings . . . . . . . . . . . . . . . . . . . . . 4667.1.3.7 Application of Coatings Using Physical Methods . . . . . . . . . 4677.1.3.8 Organic Coating Systems . . . . . . . . . . . . . . . . . . . . . . 467
7.2 CorrosionJim Hillis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 469
7.2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4697.2.2 Magnesium Protective Films . . . . . . . . . . . . . . . . . . . . 4697.2.3 Metallurgical Factors in the Corrosion of Alloys . . . . . . . . . 4707.2.4 Stress Corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . 4817.2.5 Corrosion Fatigue . . . . . . . . . . . . . . . . . . . . . . . . . . 4827.2.6 Common Causes of Corrosion Failure . . . . . . . . . . . . . . . 4847.2.7 Enviromental Factors . . . . . . . . . . . . . . . . . . . . . . . . 4887.2.7.1 Acidity/Alkalinity . . . . . . . . . . . . . . . . . . . . . . . . . . 4887.2.7.2 Specific Ions/Salts . . . . . . . . . . . . . . . . . . . . . . . . . . 4887.2.7.3 Elevated Temperature . . . . . . . . . . . . . . . . . . . . . . . . 4897.2.7.4 Organic Compounds . . . . . . . . . . . . . . . . . . . . . . . . 4897.2.8 Galvanic Corrosion/Selection of Fasteners . . . . . . . . . . . . 490
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 494
8 Engineering Requirements, Strategies and Examples . . . . . . . 499
8.1 Automotive Applications in EuropeSoenke Schumann, Horst E. Friedrich . . . . . . . . . . . . . . . . 499
8.1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4998.1.2 Potential Use of Magnesium in Vehicles . . . . . . . . . . . . . . 5038.1.3 Automotive Applications – Examples . . . . . . . . . . . . . . . 5068.1.3.1 Drive train Train Applications . . . . . . . . . . . . . . . . . . . 5068.1.3.2 Interior Applications . . . . . . . . . . . . . . . . . . . . . . . . 5198.1.3.3 Body . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5278.1.3.4 Chassis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5548.1.4 Life Cycle Assessment . . . . . . . . . . . . . . . . . . . . . . . . 5598.1.4.1 Life Cycle Inventory of Vehicles . . . . . . . . . . . . . . . . . . . 5608.1.4.2 Life Cycle Inventory of Magnesium . . . . . . . . . . . . . . . . 5638.1.5 Strategy and Outlook . . . . . . . . . . . . . . . . . . . . . . . . 565
8.2 Automotive Applications in North AmericaGerald Cole . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 569
8.2.1 Transportation Industry . . . . . . . . . . . . . . . . . . . . . . 5698.2.1.1 Introduction and Background . . . . . . . . . . . . . . . . . . . 5698.2.1.2 Magnesium in the 1970s . . . . . . . . . . . . . . . . . . . . . . 5708.2.1.3 Magnesium in the 1980s . . . . . . . . . . . . . . . . . . . . . . 5708.2.1.4 Magnesium in the 1990s . . . . . . . . . . . . . . . . . . . . . . 5718.2.1.5 Magnesium in NA vs Europe . . . . . . . . . . . . . . . . . . . . 5738.2.1.6 Engineering Magnesium Appications . . . . . . . . . . . . . . . 5898.2.2 Non-Automotive Uses for Magnesium . . . . . . . . . . . . . . . 593
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8.2.2.1 Electronics/Communication . . . . . . . . . . . . . . . . . . . . 5938.2.2.2 Hand Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5938.2.2.3 Sports Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . 5948.2.2.4 Aerospace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5948.2.3 Magnesium Manufacturing in North America . . . . . . . . . . . 5948.2.3.1 Semi-Solid Metal Casting (SSM) . . . . . . . . . . . . . . . . . . 5958.2.3.2 Thixomolding (TXM) . . . . . . . . . . . . . . . . . . . . . . . . 5958.2.3.3 Magnesium Can Replace Polymers . . . . . . . . . . . . . . . . . 5978.2.3.4 Magnesium Can be Fabricated into Macro-composites of
Plastics and Metals . . . . . . . . . . . . . . . . . . . . . . . . . 5978.2.3.5 Alloys Designed Especially for SSM and TXM . . . . . . . . . . . 5978.2.3.6 Redesigning Parts and Assemblies . . . . . . . . . . . . . . . . . 5988.2.3.7 Thermal Management and Improvement of TXM . . . . . . . . . 5988.2.3.8 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5998.2.4 Magnesium R&D in North America . . . . . . . . . . . . . . . . 6008.2.4.1 USCAR Programs . . . . . . . . . . . . . . . . . . . . . . . . . . 600
8.3 Magnesium AerospaceFrancis H. Froes, Dan Eliezer, Eli Aghion . . . . . . . . . . . . . . 603
8.3.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6038.3.2 Past Aerospace Use . . . . . . . . . . . . . . . . . . . . . . . . . 6078.3.3 Barriers to Magnesium Use in Aerospace . . . . . . . . . . . . . 617
8.4 Consumer Applications of MagnesiumSteve Erickson . . . . . . . . . . . . . . . . . . . . . . . . . . . . 620
8.4.1 Logistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6218.4.2 Power Hand Tools . . . . . . . . . . . . . . . . . . . . . . . . . . 6218.4.3 Lawn and Garden Equipment . . . . . . . . . . . . . . . . . . . 6238.4.4 Concrete Handling Tools and Equipment . . . . . . . . . . . . . 6238.4.5 Computers and Computer Hardware . . . . . . . . . . . . . . . . 6248.4.6 Electronic Equipment . . . . . . . . . . . . . . . . . . . . . . . . 6258.4.7 Optical Equipment . . . . . . . . . . . . . . . . . . . . . . . . . 6258.4.8 Sports Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . 6268.4.9 Galvanic Applications . . . . . . . . . . . . . . . . . . . . . . . . 6278.4.10 Miscellaneous Consumer Applications . . . . . . . . . . . . . . . 628
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 629
9 RecyclingHåkon Westengen . . . . . . . . . . . . . . . . . . . . . . . . . . 633
9.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 633
9.2 Classification System . . . . . . . . . . . . . . . . . . . . . . . . 6349.2.1 Process Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 6359.2.2 Class 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6369.2.2.1 Flux-based Systems . . . . . . . . . . . . . . . . . . . . . . . . . 6379.2.2.2 In-house Recycling . . . . . . . . . . . . . . . . . . . . . . . . . 638
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9.2.2.3 In-cell Recycling . . . . . . . . . . . . . . . . . . . . . . . . . . . 6399.2.3 Class 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6409.2.4 Class 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6409.2.5 Class 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6419.2.6 Class 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6419.2.7 Class 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6429.2.8 Class 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6439.2.9 Class 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 645
9.3 Recycling Using Flux . . . . . . . . . . . . . . . . . . . . . . . . 645
9.3.1 Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6459.3.1.1 Thermodynamic Restrictions . . . . . . . . . . . . . . . . . . . 647
9.4 Fluxless Refining . . . . . . . . . . . . . . . . . . . . . . . . . . 647
9.4.1 Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6489.4.2 Systems Involving Filters . . . . . . . . . . . . . . . . . . . . . . 649
9.5 Contamination Control . . . . . . . . . . . . . . . . . . . . . . . 650
9.5.1 Additional Sources of Trace Elements and Inclusions During Recycling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 651
9.5.2 Effects and Removal of Some Trace Elements . . . . . . . . . . . 6529.5.2.1 Nickel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6529.5.2.2 Iron . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6539.5.2.3 Copper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6539.5.2.4 Cobalt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6539.5.2.5 Hydrogen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6559.5.2.6 Other Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . 6559.5.3 Effects of Inclusions . . . . . . . . . . . . . . . . . . . . . . . . . 6569.5.4 Measurements of Inclusions . . . . . . . . . . . . . . . . . . . . 656
9.6 Concluding Remarks . . . . . . . . . . . . . . . . . . . . . . . . 659
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 660
Subject Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 665
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