Iron in Aluminium Alloys: Impurity and Alloying Element

360 Pages·2002·88.179 MB·\360

by  N.A. Belov (Author), A.A. Aksenov (Author), Dmitry G. Eskin (Author)

Iron in Aluminum Alloys
Advances in Metallic Alloys
A series edited by J.N. Fridlyander, All-Russian Institute ofA viation Materials,
Moscow, Russia and D.G. Eskin, Netherlands Institute for Metals Research, Delft,
The Netherlands
Volume 1
Liquid Metal Processing: Applications to Aluminium Alloy Production
!.G. Brodova, P.S. Popel and G.!. Eskin
Volume 2
Iron in Aluminum Alloys: Impurity and Alloying Element
N.A. Belov, A.A. Aksenov and D. G. Eskin
Iron in Aluminum Alloys
Impurity and Alloying Element
N.A. Belov and A.A. Aksenov
Moscow Institute of Steel and Alloys, Russia
and
D.G. Eskin
The Netherlands Institute for Metals Research
Translated from the Russian by A.I. Kozlenkov
London and New York
First published 2002 by Taylor & Francis
11 New Fetter Lane, London EC4P 4EE
Simultaneously published in the USA and Canada
by Taylor & Francis Inc,
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Taylor & Francis is an imprint of the Taylor & Francis Group
© 2002 Taylor & Francis
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ISBN 0-415-27352-8
Contents
Preface ix
List ofS ymbols and Abbreviations xv
Chapter 1
Phase Diagrams of Iron-Containing Aluminum Alloys 1
1. Aluminum-Iron Phase Diagram 3
2. Phase Diagrams of Ternary Iron-Containing Systems 7
1. AI-Fe-Be 7
2. AI-Fe-Ca 8
3. AI-Fe-Ce 9
4. AI-Fe-Co 11
5. AI-Fe-Cr 12
6. AI-Fe-Cu 14
7. AI-Fe-Hf 16
8. AI-Fe-Mg 17
9. AI-Fe-Mn 18
10. AI-Fe-Mo 19
11. AI-Fe-Nb 22
12. AI-Fe-Nd 22
13. AI-Fe-Ni 23
14. AI-Fe-Si 24
15. AI-Fe-Ti 29
16. AI-Fe-V 30
17. AI-Fe-Y 30
18. AI-Fe-Zn 31
19. AI-Fe-Zr 33
3. Phase Diagrams of Quaternary Iron-Containing Systems 34
1. AI-Fe-Be-Si 34
2. AI-Fe-Co-Cu 35
3. AI-Fe-Co-Ni 36
4. AI-Fe-Co-Si 37
5. AI-Fe-Cu-Mg 38
6. AI-Fe-Cu-Mn 41
7. AI-Fe-Cu-Ni 43
8. AI-Fe-Cu-Si 45
9. AI-Fe-Mg-Mn 48
10. AI-Fe-Mg-Si 49
11. AI-Fe-Mn-Si 52
12. AI-Fe-Mo-Si 56
13. AI-Fe-Ni-Si 56
14. AI-Fe-Ti-Si 59
v
vi CONTENTS
4. Phase Diagrams of Five-Component Iron-Containing Systems 60
1. Method for Evaluation of Five-Component Phase Diagrams
as Applied to Alloys of the AI-Fe-Cu-Mg-Si System 60
2. AI-Fe-Cu-Mg-Si 61
3. AI-Fe-Cu-Mg-Mn 71
4. AI-Fe-Cu-Mn-Si 74
5. AI-Fe-Mg-Mn-Si 75
6. AI-Fe-Mn-Si-Ti 75
5. N onequilibrium Phase Diagrams of Iron-Containing Systems 78
1. Evaluation of None quilibrium Phase Diagrams 78
2. AI-Fe-Si 80
3. AI-Fe-Mg-Si 83
4. AI-Fe-Cu-Si 86
5. AI-Fe-Ni-Si 88
Chapter 2
Structure and Properties of Iron-Containing Aluminum Alloys:
General Features 91
1. Effect ofIron on the Structure and Properties of As-Cast Alloys 91
1. Structure and Mechanical Properties of Binary Aluminum-Iron Alloys 94
2. Structure and Mechanical Properties of As-Cast Multicomponent Aluminum
Alloys with Iron in Which Silicon is not the Main Alloying Component 10 I
3. Structure and Mechanical Properties of As-Cast Multicomponent
Aluminum-Silicon Alloys with Iron 109
4. Casting Properties of Iron-Containing Aluminum Alloys 119
2. Changes in the Structure and Properties Caused by Heat Treatment 124
1. Effect of Heating on Morphology ofIron-Containing Phases 125
2. Phase Transformations during Heating 132
3. Decomposition of Aluminum Solid Solution Supersaturated
with Iron upon Solidification 136
3. Effect ofIron on the Structure and Mechanical Properties of Deformed
Aluminum and Its Alloys 138
1. Effect of Iron on Plastic Deformation and Failure in Aluminum Alloys 139
2. Processes of Recrystallization ofIron-Containing Aluminum Alloys 149
3. Effect ofIron on the Mechanical Properties of Deformed Aluminum 160
4. Physical and Corrosion Properties of Aluminum-Iron Alloys 168
1. Physical Properties of Melts 168
2. Physical Properties in the Solid State 172
3. Corrosion Resistance 177
Chapter 3
Iron as an Impurity in Aluminum Alloys 185
1. Iron Impurity in Commercial Casting Alloys 186
1. Alloys Based on the AI-Cu (2XX.0) System 188
2. Alloys Based on the AI-Mg (5XX) System 190
3. Alloys Based on the AI-Si (4XX.0 and 3XX.0) System 192
4. Alloys Based on the AI-Zn-Mg--{Cu) (7XX.0) System 198
CONTENTS vii
2. Iron Impurity in Commercial Wrought Alloys 199
1. Structure and Properties ofIngots 199
2. Effect of Iron on the Stability of Solid Solutions 208
3. Effect ofIron on the Mechanical and Service Characteristics 213
4. Effect of Iron and Manganese Impurities on the Structure and Properties
of Deformed Hypereutectic Al-Si Alloys 230
3. Refming of Aluminum and Its Alloys from Iron 233
1. Electrolytic Refining of Aluminum 234
2. Refining of Commercial Aluminum by Crystallization Methods 235
3. Refining of Aluminum by Distillation 237
4. Methods of Refining Recycled Aluminum Alloys from Iron 238
Chapter 4
Iron as an Additive in Aluminum Alloys 245
1. Commercial Wrought and Casting Aluminum Alloys with Iron Additive 245
1. Wrought Alloys ofthe Al-Fe-Ni System 246
2. Corrosion-Resistant Alloys for Nuclear Reactors 251
3. Electrical Alloys 252
4. Casting AL20 Alloy 253
5. Promising Casting Alloys with Increased Iron Content 254
2. Rapidly Solidified Alloys 260
1. Heat-Resistant Alloys Based on the Al-Fe-TM Systems 261
2. Structural Alloys with Iron, Zinc, Magnesium, and Copper Additives 265
3. Alloys with Low Thermal Expansion Based on the Al-Si System
with Iron Additive 269
4. Alloys with Amorphous and Nanocrystalline Structures 269
3. Principles of Designing Iron-Containing Aluminum Alloys 275
1. Basics of Proposed Approach 275
2. Three-Phase Eutectics with Iron-Containing Phases 278
3. Procedure for Rapid Search for Multiphase Eutectics 279
4. Examples of Multicomponent Alloys with Increased Iron Content 282
4. Composite Materials Based on the Aluminum-Iron System 283
1. Aluminum Alloys Reinforced by Wire Made ofIron-Containing Alloys 285
2. Layered Materials Based on Aluminum and Its Alloys with
Components Made ofIron Alloys 296
3. Aluminum-Iron Materials Produced by Mechanical Alloying 299
4. Components Produced from Aluminum and Its Alloys Locally
Reinforced by Elements Made ofIron-Based Alloys 304
Appendix 307
References 331
Subject Index 341

Preface
Aluminum-based alloys and composite materials constitute the most important group of
modern materials whose application, as predicted by specialists, will tend to increase in the
nearest future. Wide use of aluminum materials calls for improving their quality and prop-
erties, however, on condition that their cost remains moderate - the requirement that re-
stricts, in particular, the use of high-cost additives such as nickel, cobalt, or scandium. On
this basis, the authors consider it expedient to examine various aspects related to the pres-
ence of iron in aluminum alloys.
On the one hand, iron is a major and most harmful impurity in most commercial casting
and wrought aluminum alloys, which is the reason for its strict limitation (down to 0.05%
in some grades). On the other hand, iron is a major component in aluminum-based materials
produced with the use of new technologies, in particular, in amorphous and nanocrystalline
alloys, where its content exceeds 10%. Taking into account the record-breaking strength
level (up to 1500 MPa) achievable with these materials, as well as the low cost of iron com-
pared with any other additives, it seems quite appropriate to consider in this book the prob-
lems of physical metallurgy connected with the purposeful use of iron in aluminum alloys
as an alloying component.
Aluminum and its alloys inevitably contain impurities, i.e. chemical elements that are not
specially introduced in the alloy composition. Impurities, including iron, are of different or-
igin: they can be inherited from ores, can enter the metal in the electrolysis process, and can
be removed incompletely in the production and refming of primary aluminum. Impurities
may appear in the process of melting and casting due to the charge contamination, the in-
teraction of the metal with lining and fluxes, and the dissolution of elements of foundry
equipment and tools. And fmally, an increased impurity content may be related to the recy-
cling.
Impurities in metals can be conditionally subdivided into (i) soluble and insoluble and
(ii) metallic and nonmetallic.
Oxygen, with low solubility in liquid and solid aluminum, and hydrogen having a high
solubility in liquid aluminum and extremely low solubility in solid aluminum, are the major
nonmetallic impurities. Because of the specific interaction of these gases with aluminum,
oxygen impurity is responsible basically for oxide formation. Hydrogen dissolved in liquid
aluminum is evolved during solidification and is responsible for the formation of shrinkage
porosity. In practice, the harmful influence of gas impurities is suppressed by refining the
melt from hydrogen (blasting with inert gases or chlorine, cavitation treatment) and by fil-
tering the melt with the aim of removing oxide particles. It is worth noting that oxides are
not necessarily undesired structure elements; on the contrary, when introduced in signifi-
ix