RECENT TRENDS IN PROCESSING AND DEGRADATION OF ALUMINIUM ALLOYS Edited by Zaki Ahmad Recent Trends in Processing and Degradation of Aluminium Alloys Edited by Zaki Ahmad Published by InTech Janeza Trdine 9, 51000 Rijeka, Croatia Copyright © 2011 InTech All chapters are Open Access distributed under the Creative Commons Attribution 3.0 license, which permits to copy, distribute, transmit, and adapt the work in any medium, so long as the original work is properly cited. After this work has been published by InTech, authors have the right to republish it, in whole or part, in any publication of which they are the author, and to make other personal use of the work. Any republication, referencing or personal use of the work must explicitly identify the original source. As for readers, this license allows users to download, copy and build upon published chapters even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. Notice Statements and opinions expressed in the chapters are these of the individual contributors and not necessarily those of the editors or publisher. No responsibility is accepted for the accuracy of information contained in the published chapters. The publisher assumes no responsibility for any damage or injury to persons or property arising out of the use of any materials, instructions, methods or ideas contained in the book. Publishing Process Manager Petra Nenadic Technical Editor Teodora Smiljanic Cover Designer Jan Hyrat Image Copyright McIek, 2011. Used under license from Shutterstock.com First published November, 2011 Printed in Croatia A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from orders@intechweb.org Recent Trends in Processing and Degradation of Aluminium Alloys, Edited by Zaki Ahmad p. cm. ISBN 978-953-307-734-5 Contents Preface IX Part 1 Casting and Forming of Aluminium Alloys 1 Chapter 1 Aluminium Countergravity Casting – Potentials and Challenges 3 Bolaji Aremo and Mosobalaje O. Adeoye Chapter 2 Intermetallic Phases Examination in Cast AlSi5Cu1Mg and AlCu4Ni2Mg2 Aluminium Alloys in As-Cast and T6 Condition 19 Grazyna Mrówka-Nowotnik Chapter 3 Rotary-Die Equal Channel Angular Pressing Method 41 Akira Watazu Part 2 Welding of Aluminium Alloys 61 Chapter 4 Welding of Aluminum Alloys 63 R.R. Ambriz and V. Mayagoitia Chapter 5 Prediction of Tensile and Deep Drawing Behaviour of Aluminium Tailor-Welded Blanks 87 R. Ganesh Narayanan and G. Saravana Kumar Part 3 Surface Treatment of Aluminium Alloys 113 Chapter 6 Laser Surface Treatments of Aluminum Alloys 115 Reza Shoja Razavi and Gholam Reza Gordani Chapter 7 Microstructural Changes of Al-Cu Alloys After Prolonged Annealing at Elevated Temperature 155 Malgorzata Wierzbinska and Jan Sieniawski VI Contents Chapter 8 PIII for Aluminium Surface Modification 175 Régulo López-Callejas, Raúl Valencia-Alvarado, Arturo Eduardo Muñoz-Castro, Rosendo Pena-Eguiluz, Antonio Mercado-Cabrera, Samuel R. Barocio, Benjamín Gonzalo Rodríguez-Méndez and Anibal de la Piedad-Beneitez Chapter 9 Optimizing the Heat Treatment Process of Cast Aluminium Alloys 197 Andrea Manente and Giulio Timelli Part 4 Mechanical Behavior of Aluminium Alloys and Composites 221 Chapter 10 High Strength Al-Alloys: Microstructure, Corrosion and Principles of Protection 223 Anthony E. Hughes, Nick Birbilis, Johannes M.C. Mol, Santiago J. Garcia, Xiaorong Zhou and George E. Thompson Chapter 11 Mechanical Behavior and Plastic Instabilities of Compressed Al Metals and Alloys Investigated with Intensive Strain and Acoustic Emission Methods 263 Andrzej Pawelek Chapter 12 Aluminum Alloys for Al/SiC Composites 299 Martin I. Pech-Canul Part 5 Corrosion and Mechanical Damage of Aluminium Alloys 315 Chapter 13 Effects of Dry Sliding Wear of Wrought Al-Alloys on Mechanical Mixed Layers (MML) 317 Mariyam Jameelah Ghazali Chapter 14 Comparison of Energy-Based and Damage-Related Fatigue Life Models for Aluminium Components Under TMF Loading 329 Eichlseder Wilfried, Winter Gerhard, Minichmayr Robert and Riedler Martin Chapter 15 Deformation Characteristics of Aluminium Composites for Structural Applications 347 Theodore E. Matikas and Syed T. Hasan Chapter 16 Corrosion Behavior of Aluminium Metal Matrix Composite 385 Zaki Ahmad, Amir Farzaneh and B. J. Abdul Aleem Contents VII Chapter 17 Interrelation Between Failure and Damage Accumulation in the Pre-Fracture Zone Under Low-Cycle Loading 407 Vladimir Kornev, Evgeniy Karpov and Alexander Demeshkin Part 6 Microstructures, Nanostructures and Image Analysis 423 Chapter 18 Nanostructure, Texture Evolution and Mechanical Properties of Aluminum Alloys Processed by Severe Plastic Deformation 425 Abbas Akbarzadeh Chapter 19 Statistical Tests Based on the Geometry of Second Phase Particles 459 Viktor Beneš, Lev Klebanov, Radka Lechnerová and Peter Sláma Chapter 20 Microstructural Evolution During the Homogenization of Al-Zn-Mg Aluminum Alloys 477 Ali Reza Eivani, Jie Zhou and Jurek Duszczyk Preface Aluminum is the second most plentiful element on the earth and it became a competition in 19 th century. The huge demand of aluminum is projected to get 70 million tons, over 30 millions being obtained from recycled scrap. The scope of aluminum ranges from household to space vehicles. Dramatic advances in casting,welding,forming and eco friendly methods of production have made aluminum and aluminum alloys highly attractive candidate for automotive and aerospace industry, because of their wide range of attributes such as high strength, resistance to corrosion, low density, high reflectively, high ductility and proven reliability. The developments in the last two decades have been revolutionary and well documented both for wrought, heat treatable and non-heat treatable alloys. New developments in methods of casting, forming, welding, environmental degradation, grain refinement and particle size at nano and micro scale have made big impact on their demand for space and automotive industry. Despite serious competition from composites, aluminum alloys are still the king in these industries, as exemplified by 777 Airbus. Aluminium is a very versatile metal and can be cast in any form, stamped, forged, machine, brazed and resin bonded. Substantial evidence has been gathered on formability which affects the structural integrity of the components. The demand on quality and integrity of welding is increasing on military and commercial aircraft. This includes improved toughness, lower weight and increased resistance to corrosion fatigue. The progress made in welding, analysis of different techniques and their impact on micro structural characteristics has been discussed in several chapters in the hinder the section “welding, casting and forming”. Ambriz Richardo has discussed this topic whereas Saravana Kumar has provided valued information on tailored blanks and deep drawing behavior of aluminum alloys. Because of high plastic strain, levels, rigid strength requirements and high quality controls are required for forming processes ranging from single to multiple stage because of increasingly dynamic and competitive market demands which includes outstanding toughness and a high resistance to corrosion fatigue. Various casting process such as direct chill casting, rotary die equal channel angular processing, counter gravity casting and centrifugal casting is described by Aremo Bolaji, Watazu Akira and others have shown new X Preface dimensions in the field of casting. Dramatic changes in surface treatment have proved highly effective in the life cycle of aluminum alloys as shown by Shoja Razavi Reza, Wierzbinska Malgorzata, Lopez-Cellajas Regulo, Metikas Theodore and Morwka-Nowotnik Grazyna have added new data to new information. Improvements in surface topography and stability are only achieved successfully by combining electrochemistry, microstructures and the role of micro/nano particles new methods of surface modifications are described by Akbarzadeh Abbas, Timelli Giulio and Kornev Vladimir. Corrosion is a serious thread to aluminum alloys and aluminum based metal matrix composites reinforced by silicon carbide. A brief mechanism of corrosion of composited is given by Zaki Ahmad. Environmental damages such as corrosion fatigue in aluminum alloys and their mechanism have been described by Ghazali Mariam and Eichlseder Wilfried. The principle behind the chapters in book was an analysis of the procedures such as casting, forming, welding and environmental degradation which have a strong bearing on the integrity of aerospace structures and automotive. The authors have addressed the problems of grain refinement, micro segragation, casting defects, crack growth, weld defects to show to what levels the aluminum alloys have been technically elevated. The chapters were selected on a rigid criteria of which novelty and new approaches were the main pillars. I hope the book would be very useful for practicing engineers, technicians, senior students and all those interested in aluminum alloys in particular the technical staff of aerospace, automotive and defense industry. Chapters on casting, welding and others could be used to support their textbook at a graduate level. This book is profusely illustrated to make the concepts clear to the readers. While editing the book I had the problems of shifting from one country other which prolonged my editing work for which I apologize. I thank Mr. Mishaal Ahmed (my grandson), Manzar Ahmed, Intesar Ahmed, Shamsujehan, Huma Sabir and Abida Sultana, they provided me with the mental support for the work not the least, the spirit of my beloved dead son Intekhab Ahmed drove me through very hard times while reviewing the chapters. I am very grateful to KFUPM who gave me the moral support. I am specially indebted to Dr Faleh Al Sulaiman vice rector of technology at KFUPM, Dr Nasir Aqeeli, Mr Faheemuddin and Mr Abdul Aleem of M.E department of KFUPM. I also thanks Dr M. Budair rector of Al-Jouf University for his moral support. In the end I thank the Al Mighty to give me the moral courage to undertake the responsibility. I am grateful to InTech publisher for giving me the honor of being the chief editor of this book. [...]... and entrainment in the mould Aluminium Countergravity Casting – Potentials and Challenges Fig 5 A Blow hole defect in an aluminum casting at 100× magnification Fig 6 Gas porosity in aluminium casting at 1000× magnification 7 8 Recent Trends in Processing and Degradation of Aluminium Alloys 3.3 Shrinkage Shrinkage is the natural consequence of liquid to solid transformation of the melt during cooling... appearance of volumetric shrinkage defect in an aluminium section 3.4 Pouring defects During pouring of the melt, there is considerable splashing and sloshing about of the melt This entrains significant quantities of air and non-metallic inclusions in the mould Such entrained material degrades casting quality This problem is often mitigated by incorporation of complex gating systems designed using advanced... conventional metal casting techniques As such it is gradually making in- roads into traditional investment casting applications and also in novel materials production 10 Recent Trends in Processing and Degradation of Aluminium Alloys Fig 8 Cross-section of a countergravity cast rod showing the absence of volumetric shrinkage defect as evident from the convex meniscus at the top of the rod Fig 9 An investment mould... oxidation, shrinkage defects and pouring defects Defects are naturally undesirable because they can result in low strength, poor surface finish and high number of rejects in a batch of cast products 6 Recent Trends in Processing and Degradation of Aluminium Alloys Fig 4 The vacuum is maintained until the cavity is completely filled Vacuum pressure is released causing un-solidified melt to flow back into the... pokes through and sits in the conical depression of the lock-nut The “square” fit of the two, depicted in figure 2, ensures a sealing of the flask interior from the external environment 4 Recent Trends in Processing and Degradation of Aluminium Alloys Fig 1 Typical setup of the countergravity casting process Fig 2 Down sprue, with conical base (a) is integrated with the rest of the investment mould... Morphology of AlSi5Cu1Mg alloy in the as-cast state: (a,c) unetched and (b,d) etched In order to identify the intermetallic phases in the examined alloy, series of elemental maps were performed for the elements line Al-K, Mg-K, Fe-K, Si-K, Cu-K and Mn-K (Fig 3 and 4) The maximum pixel spectrum clearly shows the presence of Al, Mg, Fe, Si, Cu and Mn in the 24 Recent Trends in Processing and Degradation of Aluminium. .. cooling and is common in most metals Shrinkage is particularly severe in aluminium alloys In aluminium alloys, the volumetric shrinkage ranges from 3.5% to 8% (Kaufman and Rooy, 2004) This manifests as shrinkage cavities in larger portions of the casting This is often counteracted by strategic placement of risers Figure 7 shows the typical appearance of volumetric shrinkage defect in an aluminium section... die casting, melt is sprayed at high velocity into the die and cavity-atmosphere tends to be admixed and entrapped in castings during the Aluminium Countergravity Casting – Potentials and Challenges 9 turbulent cavity-fill (Jorstad, 2003) The process of air melting and pouring also inevitably introduces oxides, formed during melting, into the cast product Significant inclusions segregation at grain boundaries... to finish this preface by the famous saying of Albert Einstein “Any fool can make things bigger, but it takes a genius to make the things smaller” I hope this small book would prove an asset in pursuit of knowledge on aluminum alloys Dr Zaki Ahmad (Professor Emeritus) C Eng, UK, FIMMM, UK King Fahd University of Petroleum and Minerals, Dhahran Saudi Arabia XI Part 1 Casting and Forming of Aluminium. .. predict and avoid bubble streams in metal castings In: Desktop Engineering, Design Engineering and Technology Magazine, March 6th 2011, Available from: < http://www.deskeng.com/articles/aaaype.htm> 2 Intermetallic Phases Examination in Cast AlSi5Cu1Mg and AlCu4Ni2Mg2 Aluminium Alloys in As-Cast and T6 Condition Grażyna Mrówka-Nowotnik Rzeszów University of Technology, Department of Materials Science Poland . RECENT TRENDS IN PROCESSING AND DEGRADATION OF ALUMINIUM ALLOYS Edited by Zaki Ahmad Recent Trends in Processing and Degradation of Aluminium Alloys Edited. aluminum casting at 10 0× magnification Fig. 6. Gas porosity in aluminium casting at 10 00× magnification Recent Trends in Processing and Degradation of Aluminium Alloys 8 3.3 Shrinkage. poor surface finish and high number of rejects in a batch of cast products. Recent Trends in Processing and Degradation of Aluminium Alloys 6 Fig. 4. The vacuum is maintained until the