Download or read book Aluminum Lithium Alloys written by N Eswara Prasad and published by Butterworth-Heinemann. This book was released on 2013-09-20 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt: Because lithium is the least dense elemental metal, materials scientists and engineers have been working for decades to develop a commercially viable aluminum-lithium (Al-Li) alloy that would be even lighter and stiffer than other aluminum alloys. The first two generations of Al-Li alloys tended to suffer from several problems, including poor ductility and fracture toughness; unreliable properties, fatigue and fracture resistance; and unreliable corrosion resistance. Now, new third generation Al-Li alloys with significantly reduced lithium content and other improvements are promising a revival for Al-Li applications in modern aircraft and aerospace vehicles. Over the last few years, these newer Al-Li alloys have attracted increasing global interest for widespread applications in the aerospace industry largely because of soaring fuel costs and the development of a new generation of civil and military aircraft. This contributed book, featuring many of the top researchers in the field, is the first up-to-date international reference for Al-Li material research, alloy development, structural design and aerospace systems engineering. - Provides a complete treatment of the new generation of low-density AL-Li alloys, including microstructure, mechanical behavoir, processing and applications - Covers the history of earlier generation AL-Li alloys, their basic problems, why they were never widely used, and why the new third generation Al-Li alloys could eventually replace not only traditional aluminum alloys but more expensive composite materials - Contains two full chapters devoted to applications in the aircraft and aerospace fields, where the lighter, stronger Al-Li alloys mean better performing, more fuel-efficient aircraft

Download or read book Aluminium Lithium Alloys III written by Colin Baker and published by Institute. This book was released on 1986 with total page 660 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aluminum Lithium Alloys written by G. Jagan Reddy and published by Elsevier Inc. Chapters. This book was released on 2013-09-20 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mechanical working of Al–Li alloys is primarily concerned with aerospace alloy rolled products (sheet and plate), extrusions, and to a lesser extent forgings. These products are fabricated by hot working with intermittent and final heat treatments. This thermomechanical processing (TMP) can be rather complex for the modern 3rd generation Al-Li alloys, but is necessary to obtain optimum combinations of properties. This Chapter is in two parts. Part 1 discusses the ‘workability’ of metals and alloys and the hot deformation characteristics of Al–Li alloys, leading to the concept of Process Maps. A comprehensive Process Map for a binary Al–Li alloy illustrates the usefulness of these Maps for defining temperature–strain rate regions for safe and unsafe hot working, recrystallization and recovery, and superplastic behaviour Part 2 provides some general considerations about processing Al–Li alloy products, followed by a review and discussion of the currently available information for 3rd generation alloys. It is concluded that their complex TMP schedules may make it difficult to obtain optimum combinations of properties for thicker products.

Download or read book Aluminum Lithium Alloys written by R.J.H. Wanhill and published by Elsevier Inc. Chapters. This book was released on 2013-09-20 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: The material and manufacturing property requirements for selection and application of 3rd generation aluminium-lithium (Al–Li) alloys in aircraft and spacecraft are discussed. Modern structural concepts using Laser Beam Welding (LBW), Friction Stir Welding (FSW), SuperPlastic Forming (SPF) and selective reinforcement by Fibre Metal Laminates (FMLs) are also considered. Al–Li alloys have to compete with conventional aluminium alloys, Carbon Fibre Reinforced Plastics (CFRPs) and GLAss REinforced FMLs (GLARE), particularly for transport aircraft structures. Thus all these materials are compared before discussing their selection for aircraft. This is followed by a review of the aluminium alloy selection process for spacecraft. Actual and potential applications of 3rd generation Al–Li alloys are presented. For aircraft it is concluded that the competition between different material classes (aluminium alloys, CFRPs and FMLs) has reached a development stage where hybrid structures, using different types of materials, may become the rule rather than the exception. However, aluminium alloys are still the main contenders for spacecraft liquid propellant launchers.

Download or read book Aluminum lithium Alloys written by Ramesh J. Kar and published by . This book was released on 1988 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aluminum Lithium Alloys written by Olga Grushko and published by CRC Press. This book was released on 2016-11-18 with total page 337 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aluminum–Lithium Alloys: Process Metallurgy, Physical Metallurgy, and Welding provides theoretical foundations of the technological processes for melting, casting, forming, heat treatment, and welding of Al–Li alloys. It contains a critical survey of the research in the field and presents data on commercial Al–Li alloys, their phase composition, microstructure, and heat treatment of the ingots, sheets, forgings, and welds of Al–Li alloys. It details oxidation kinetics, protective alloying, hydrogen in Al–Li alloys, and crack susceptibility. It also discusses grain structure and solidification, as well as structural and mechanical properties. The book is illustrated with examples of Al–Li alloy applications in aircraft structures. Based on the vast experience of the coauthors, the book presents recommendations on solving practical problems involved with melting and casting ingots, welding of Al–Li alloys, and producing massive stampings for welded products. Provides comprehensive coverage of Al–Li alloys, not available in any single source. Presents research that is at the basis of the production technology for of ingots and products made of Al–Li alloys. Combines basic science with applied research, including upscaling and industrial implementation. Covers welding of Al–Li alloys in detail. Discusses gas and alkali-earth impurities in Al–Li alloys. Describes technological recommendations on casting and deformation of Al–Li alloys.

Download or read book Aluminum Lithium Alloys written by T.S. Srivatsan and published by Elsevier Inc. Chapters. This book was released on 2013-09-20 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: The emergence of Al–Li alloys as potential light metal, for safe use in a spectrum of aircraft structures and related aerospace applications has in recent years engendered an unprecedented widespread interest aimed at studying, understanding and improving their mechanical properties. In this chapter, we present and discuss some of the key aspects relevant to aluminum-lithium alloys, spanning the specific domain of precipitation kinetics as influenced by composition and heat treatment, intrinsic microstructural features and their effects, the fundamental mechanisms contributing to strength, ductility, fracture toughness, and overall anisotropy in mechanical properties of these alloys. The tensile behavior of representative first generation, second generation and third generation aluminum-lithium alloys is also presented and briefly discussed. Microstructural influences on mechanical properties are examined with specific reference to matrix microstructural features, dislocation-microstructural feature interaction, and matrix slip characteristics.

Download or read book Aluminum Lithium Alloys written by S.P. Lynch and published by Elsevier Inc. Chapters. This book was released on 2013-09-20 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aluminium-Lithium (Al–Li) alloys have been of interest since the 1950s when they were first used on a military aircraft. Having lithium as the main alloying element in Al alloys is attractive since (i) each 1 wt% Li reduces the density by ~3% and increases modulus by ~5%, and (ii) high strengths can be achieved by precipitation-hardening. During the 1980s, extensive research and development was carried out on alloys with high lithium contents (>2 wt%≡~8 at%) such as AA 8090 (Al 2.4 Li 1.2 Cu 0.7 Mg 0.12 Zr) (wt%). The mechanical properties of these ‘second-generation’ Al–Li alloys, however, did not match those of conventional Al (-Zn)-Mg-Cu alloys, and the lower fracture toughness of these alloys (for equivalent strengths was a particular problem. Thus, 2nd generation Al–Li alloys did not see widespread use. The experience with 2nd generation Al–Li alloys led to the development of ‘3rd generation’ alloys with lower Li contents (0.75–1.7 wt%), and some of these alloys have a better overall balance of properties, including fracture toughness, than the best available conventional Al alloys. These 3rd generation Al–Li alloys should therefore see extensive use in future civil and military aircraft. This chapter on fracture toughness and fracture modes of aerospace Al–Li alloys outlines why fracture toughness is important for aerospace structures and components, and summarises testing procedures and terminologies in regard to plane-strain and plane-stress fracture toughness. The relationships between fracture toughness/fracture modes and microstructural features such as grain morphology, constituent particles, impurity phases, matrix precipitates, grain-boundary precipitates, and grain boundary segregation, are then discussed. Proposed explanations for the low fracture toughness of 2nd generation Al–Li alloys, associated with low-energy intergranular and transgranular shear fractures, are discussed in some depth, followed by a summary of the alloy-design principles behind the development of 3rd generation Al–Li alloys with a much improved resistance to low-energy fracture modes. Quantitative data for fracture toughness of 2nd and 3rd generation Al–Li alloys in comparison with conventional Al alloys are provided, showing that 3rd generation Al–Li alloys have outstanding combinations of toughness and strength combined with reduced densities. The superior toughness of 3rd generation Al–Li alloys compared with 2nd generation alloys is reflected in the differences in fracture-surface topography and fracture path. The chapter concludes with a summary of the current and proposed uses of 3rd generation Al–Li alloys in aircraft structures and components

Download or read book Aluminum Lithium Alloys written by N. Eswara Prasad and published by Elsevier Inc. Chapters. This book was released on 2013-09-20 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt: The formation of metastable and equilibrium phases in binary Al–Li, ternary Al–Li–Mg and Al–Li–Cu, and quaternary Al–Cu–Li–Mg alloys has been studied by using a variety of experimental techniques including differential scanning calorimetry, electrical resistivity, X-ray diffraction, conventional and high-resolution electron microscopy and 3D atom probe measurements. Al3Li (δ′) is the strengthening phase in binary Al–Li and ternary Al–Li–Mg alloys. Mg reduces the solubility of Li in Al and also substitutes for Li in δ′. The characteristics of θ′ (and θ) and T1 phases in Al–Li–Cu alloys and the composition limits where these phases are formed are well understood. For low Li contents (1.4–1.5%). Formation of T1 is promoted by small additions of Ag and Mg and by cold work prior to artificial aging. Zr forms the metastable β′ (Al3Zr) phase, which has an appreciable effect on retarding recrystallization besides providing nucleation sites for composite δ′ particles. Sc and Yb additions behave in a similar way; the added advantage is improved creep strength. The available information from phase equilibria studies of Al–Li–Cu–Mg alloys is somewhat limited, but sufficient to give an indication of the desirable solution treatment and aging temperatures and the phases formed at these temperatures. 3D atom probe studies suggest the involvement of Mg atoms in the formation of clusters which lead to the formation of the T1 phase, during artificial ageing of aging of quenched Al–Cu–Mg–Ag alloys. All these aspects are covered in detail, with specific reference to different commercial and semi-commercial Al–Li alloys, wherever possible.

Download or read book Aluminum lithium Alloys written by T. H. Sanders and published by . This book was released on 1989 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structure Property Correlations in Al Li Alloy Integrally Stiffened Extrusions written by Stephen J. Hales and published by DIANE Publishing. This book was released on 2001 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aluminum Lithium Alloys written by K.V. Jata and published by Elsevier Inc. Chapters. This book was released on 2013-09-20 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt: This chapter describes the development of crystallographic texture and its effects on mechanical properties in aluminum-lithium alloys. Crystallographic texture evolves during the forming of wrought products from cast ingots of Al-Li alloys and consequently affects the mechanical properties. Practical approaches to control the texture have been developed and have been successfully used in the products obtained from industrial-scale ingots. This texture tailoring has significantly reduced the yield strength anisotropy. In addition, theoretical approaches have been used to model the yield strength anisotropy of aluminum alloys in the presence of complex precipitates.

Download or read book Aluminum Lithium Alloys written by R.J.H. Wanhill and published by Elsevier Inc. Chapters. This book was released on 2013-09-20 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: The structural and engineering property requirements for widespread deployment of aluminium-lithium (Al-Li) alloys in aircraft are discussed, particularly with respect to commercial transport aircraft. The development of Al-Li alloys has been driven mainly by the fact that additions of lithium to aluminium alloys lowers the density and increases the elastic modulus, thereby offering the potential of significant weight savings with respect to conventional (non-lithium containing) alloys. The first use of Al-Li alloys in aircraft goes back to the late 1950s (alloy AA 2020) and mid-1960s (alloys 1420 and 1421). These materials are referred to as the 1st generation Al-Li alloys. Subsequently there have been two major development programmes resulting in the 2nd and 3rd generation alloys. Development of the 2nd generation alloys began in the 1970s and continued through the 1980s. Attempts were made to develop families of Al-Li alloys for widespread replacement of conventional alloys. Ultimately this was unsuccessful except for ‘niche’ applications. The failure to find widespread application was associated largely with the too-high lithium contents of the alloys (typically more than 2 wt%). This resulted in serious disadvantages, including mechanical property anisotropy, low short-transverse ductility and fracture toughness, and thermal instability. Development of the 3rd generation Al-Li alloys began in the late 1980s and is ongoing. These alloys have significantly reduced lithium contents (0.75 – 1.8 wt%) and there are other important compositional changes. Silver and zinc have been added for strength, and zinc improves the corrosion resistance; and manganese is added besides zirconium, which was already present in 2nd generation alloys, to control recrystallization and texture. These differences and improved knowledge about thermomechanical processing and heat-treatment have resulted in a family of alloys with significant property advantages covering all major structural areas and applications for transport aircraft.

Download or read book Aluminum Lithium Alloys written by N.J.H. Holroyd and published by Elsevier Inc. Chapters. This book was released on 2013-09-20 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: Industrial interest in wrought heat-treatable aluminium-lithium (Al–Li) based alloys dates back to around 1919 in Germany. However the exploitation of these alloys has historically been limited by their mechanical property anisotropy and concerns over their localized corrosion resistance and temperature stability. Recently, in the last ten years, alloy and process development has resulted in alloy compositions and thermomechanical treatments that potentially can overcome these issues. To put these developments in perspective we have reviewed the corrosion characteristics of first, second and third generation alloys with an emphasis on localized corrosion (intergranular and exfoliation) and stress corrosion cracking (SCC). Intergranular corrosion susceptibility of Al–Li–Cu and Al–Li–Cu–Mg alloys increases with copper content, and the depth of attack increases with ageing, i.e. UAPA~30 mm) further analysis of corrosion test results is required.

Download or read book Aluminum Lithium Alloys written by Edgar A. Starke and published by Elsevier Inc. Chapters. This book was released on 2013-09-20 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: This chapter provides a brief overview and history of the development of aluminium-lithium alloys from the earlier days of the discovery of age hardening by Alfred Wilm to its current status. It examines the progress of alloy development from simple binary alloys to the complex alloys that are currently used in aerospace systems. The driving force for this development has been the advantages gained by weight reduction of aerospace systems by replacing conventional aluminium alloys with the lower density higher modulus aluminium-lithium alloys. The problems associated with the development of these alloys and the scientific solutions to solving these problems are described.

Download or read book New Materials for Next Generation Commercial Transports written by Committee on New Materials for Advanced Civil Aircraft and published by National Academies Press. This book was released on 1996-03-29 with total page 99 pages. Available in PDF, EPUB and Kindle. Book excerpt: The major objective of this book was to identify issues related to the introduction of new materials and the effects that advanced materials will have on the durability and technical risk of future civil aircraft throughout their service life. The committee investigated the new materials and structural concepts that are likely to be incorporated into next generation commercial aircraft and the factors influencing application decisions. Based on these predictions, the committee attempted to identify the design, characterization, monitoring, and maintenance issues that are critical for the introduction of advanced materials and structural concepts into future aircraft.

Download or read book Aluminum Alloys Contemporary Research and Applications written by A. K. Vasudevan and published by Elsevier. This book was released on 2012-12-02 with total page 727 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses the structure and properties of the current and potential aluminum alloys in terms of their structure (and structural transformations by new processing methods) and the relationship between structure and mechanical and other properties. The alternative materials that challenge aluminum are considered as well, since the challenge of new competitive materials is a strong influence on innovation. The book bridges the gap between current scientific understanding and engineering practice. It is an up-to-date reference that will be of use to researchers and advanced students in metallurgy and materials engineering.