Download or read book Achieving Ultra high Strength of Al Cu Li and Al Zn Mg Cu Alloys by the Combination of High Pressure Torsion and Age Hardening written by Jiahui Dong and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 High Strength Cast Aluminum Alloy Development written by Edward A. Drushitz and published by . This book was released on 2013 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this research was to understand how chemistry and processing affect the resulting microstructure and mechanical properties of high strength cast aluminum alloys. Two alloy systems were investigated including the Al-Cu-Ag and the Al-Zn-Mg-Cu systems. Processing variables included solidification under pressure (SUP) and heat treatment. This research determined the range in properties that can be achieved in BAC 100TM (Al-Cu micro-alloyed with Ag, Mn, Zr, and V) and generated sufficient property data for design purposes. Tensile, stress corrosion cracking, and fatigue testing were performed. CuAl2 and Al-Cu-Fe-Mn intermetallics were identified as the ductility limiting flaws. A solution treatment of 75 hours or longer was needed to dissolve most of the intermetallic CuAl2. The Al-Cu-Fe-Mn intermetallic was unaffected by heat treatment. These results indicate that faster cooling rates, a reduction in copper concentration and a reduction in iron concentration might increase the ductility of the alloy by decreasing the size and amount of the intermetallics that form during solidification. Six experimental Al-Zn-Mg-Cu series alloys were produced. Zinc concentrations of 8 and 12wt% and Zn/Mg ratios of 1.5 to 5.5 were tested. Copper was held constant at 0.9%. Heat treating of the alloys was optimized for maximum hardness. Al-Zn-Mg-Cu samples were solution treated at 441°C (826°F) for 4 hours before ramping to 460°C (860°F) for 75 hours and then aged at 120°C (248°F) for 75 hours. X-ray diffraction showed that the age hardening precipitates in most of these alloys was the T phase (Mg32Zn31.9Al17.1). Tensile testing of the alloys showed that the best mechanical properties were obtained in the lowest alloy condition. Chilled Al-8.2Zn-1.4Mg-0.9Cu solidified under pressure resulted in an alloy with a yield strength of 468MPa (68ksi), tensile strength of 525MPa (76ksi) and an elongation of 9%.
Download or read book Thermomechanical Treatments on High Strength Al Zn Mg Cu Alloys written by E. DI RUSSO and published by . This book was released on with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Influence of Quenching and Aging on Fracture Toughness of the Al Zn Mg Cu Alloy 7449 written by J. Robinson and published by . This book was released on 2014 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: This investigation characterises the fracture toughness of the very high strength Aluminium alloy 7449. This Al-Zn-Mg-Cu alloy is heat treatable and relies on rapid quenching from the solution heat treatment temperature to promote subsequent artificial aging. While the influence of quench paths on strength is well understood and can be predicted using techniques like quench factor analysis, the influence of quench rate on fracture toughness is more challenging. The rate of quenching can influence the fracture toughness through complex precipitation reactions occurring during cooling. The precipitate locations dictate the magnitude of the detrimental effect on the fracture toughness. In this investigation, the fracture toughness of 7449 in two product forms was measured using compact tension specimens cut from forged blocks and rolled plate. These plane strain (KIC) results were also augmented with Charpy impact tests. Various quench conditions were investigated, including water at three different temperatures and poly oxyethylene glycol (PAG) in two concentrations. The influence of standard and novel aging procedures including retrogression and reaging was also determined. The combinations of strength and toughness have been related to the prevailing microstructural condition. Fracture toughness magnitudes were found to vary most significantly with rapidity of cooling from the solution treatment temperature, with the subsequent aging treatments having a much smaller effect.
Download or read book Chapter Formability and Performance of Al Zn Mg Cu Alloys with Different Initial Tempers in Creep Aging Process written by Heng Li and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The initial temper may directly affect the deformation behavior and material performance in creep age forming (CAF) process. Five heat treatment states are selected as the initial tempers for CAF, namely, solution, peak-aging (T6), over-aging (T73), retrogression and re-solution. The formability and performance of an Al-Zn-Mg-Cu alloy with the above initial tempers in creep aging process are investigated via using creep and stress relaxation aging tests, mechanical property tests, corrosion resistance tests and microstructure analysis. The differences of formability are attributed to the inhibitions of different distributed matrix precipitates (MPts) on the dislocation movement, namely, the more coarsening the MPts is, the easier the dislocation movement. During creep aging process, the mechanical properties are improved for the solution, retrogression and re-solution tempers with fine MPts, but reduced for the T6 and T73 tempers due to coarsening of MPts. Since the distribution of grain boundary precipitates (GBPs) becomes discontinuous, the corrosion resistances of the creep aged specimens are enhanced for all initial tempers. Taking both mechanical properties and corrosion resistances into account, the re-solution temper may be a preferable choice to achieve high performance of the components beyond the precise shape in CAF.
Download or read book Microstructural Evolution During Aging of an Al Cu Li Ag Mg Zr Alloy written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-20 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: Alloys in the Al-Cu-Li Ag-Mg subsystem were developed that exhibit desirable combinations of strength and ductility. These Weldalite (trademark) alloys, are unique for Al-Cu-Li alloys in that with or without a prior cold stretching operation, they obtain excellent strength-ductility combinations upon natural and artificial aging. This is significant because it enables complex, near-net shape products such as forgings and super plastically formed parts to be heat treated to ultra-high strengths. On the other hand, commercial extrusions, rolled plates and sheets of other Al-Cu-Li alloys are typically subjected to a cold stretching operation before artificial aging to the highest strength tempers to introduce dislocations that provide low-energy nucleation sites for strengthening precipitates such as the T(sub 1) phase. The variation in yield strength (YS) with Li content in the near-peak aged condition for these Weldalite (trademark) alloys and the associated microstructures were examined, and the results are discussed. Kumar, K. S. and Brown, S. A. and Pickens, Joseph R. Unspecified Center ...
Download or read book Development of High strength Al Zn Mg Cu Alloys with Reduced Quench sensitivity written by H. A. Holl and published by . This book was released on 1968 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Formability and Performance of Al Zn Mg Cu Alloys with Different Initial Tempers in Creep Aging Process written by Heng Li and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The initial temper may directly affect the deformation behavior and material performance in creep age forming (CAF) process. Five heat treatment states are selected as the initial tempers for CAF, namely, solution, peak-aging (T6), over-aging (T73), retrogression and re-solution. The formability and performance of an Al-Zn-Mg-Cu alloy with the above initial tempers in creep aging process are investigated via using creep and stress relaxation aging tests, mechanical property tests, corrosion resistance tests and microstructure analysis. The differences of formability are attributed to the inhibitions of different distributed matrix precipitates (MPts) on the dislocation movement, namely, the more coarsening the MPts is, the easier the dislocation movement. During creep aging process, the mechanical properties are improved for the solution, retrogression and re-solution tempers with fine MPts, but reduced for the T6 and T73 tempers due to coarsening of MPts. Since the distribution of grain boundary precipitates (GBPs) becomes discontinuous, the corrosion resistances of the creep aged specimens are enhanced for all initial tempers. Taking both mechanical properties and corrosion resistances into account, the re-solution temper may be a preferable choice to achieve high performance of the components beyond the precise shape in CAF.
Download or read book The Relations Between Thermodynamics Nanostructure Hardening and Stability of an Al Cu Mg Alloy Processed by High Pressure Torsion written by Ying Chen and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Microalloying and Heat Treatment on the Structure and Properties of a New Super High Strength Al Zn Mg Cu Alloy written by Yi-Lei Wu and published by . This book was released on 1997 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book THE INFLUENCE OF PRIOR NATURAL AGING ON ARTIFICIAL AGE HARDENING IN AL MG SI ALLOYS written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : Aluminum alloys of the 6000 series (Al-Mg-Si) are among the most prevalent and established structural materials in the world. Their use dates back decades, and currently they are crucial to the construction and transportation industries. One of the primary reasons for this is heat-treatability, i.e. the ability to control strength and ductility relationships with a relatively low temperature artificial aging treatment. Although multiple aluminum alloys can be employed for this purpose (e.g. 2000, 7000 series), Al-Mg-Si alloys are capable of achieving a highly attractive combination of moderate to high strength (sometimes > 350 MPa UTS), high ductility (>20% elongation), and excellent corrosion resistance, extrudability, weldability, and surface finish. 350 MPa UTS), high ductility (>20% elongation), and excellent corrosion resistance, extrudability, weldability, and surface finish.20% elongation), and excellent corrosion resistance, extrudability, weldability, and surface finish. The largest unknown in the world of 6000 series alloys today is a result of natural aging (NA) prior to artificial aging (AA), and the rather mysterious impacts on strengthening precipitation and hardenability that are produced. The origins of these impacts involve complex interactions between solute atoms, solute-clusters, and vacancies, which ultimately influence the kinetics and thermodynamics of precipitation. Although this has been the topic of extensive research in recent years, the actual mechanisms responsible are still very controversial. This dissertation will focus on the effects of prior natural aging on artificial age hardening response under a wide range of compositional and heat treatment conditions. Ultimately it will be shown that the behavior of naturally aged solute-clusters during artificial aging is dependent on alloy composition, and furthermore that these clusters are directly responsible for the changes in strengthening precipitation and performance. General background to the topic and an overview of the experimental methods are described in Chapters 1-2. The most important chapters of this dissertation are Chapters 3-4, which focus on the influence of prior NA in high strength Al-Mg-Si alloys after a water quench from the solutionization temperature. In Chapter 3, a compositional (Mg/Si) dependence of the NA effect is identified, and proposed to due to a corresponding dependence of NA cluster stability during artificial aging. In Chapter 4, the actions of NA clusters at AA temperatures are investigated with atom probe tomography, and the relative thermal stabilities suggested in Chapter 3 are proven. The rest of the dissertation includes studies focused on the NA effect under different compositional and heat-treatment conditions, using the previous cluster thermal stability findings to aid in analysis (Chapter 5). Mechanical property characterization of key experimental conditions is performed in Chapter 6, and good agreement with the previous results is found. Finally, key conclusions, implications, and suggested future work is summarized in Chapter 7 & 8.
Download or read book Optimizing the Heat Treatment of High Strength Al Si Mg and Al Cu Mg Zn written by Ibrahim Mohamed Fawzy and published by LAP Lambert Academic Publishing. This book was released on 2015-10-30 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: The design of aeronautical alloys requires the use of these particular alloys for their strength and ductility. These properties can be further enhanced by controlling the added alloying elements as well as the heat treatment parameters. The objective of the present work was to determine the effect of the interactions between element additions and heat treatment on the alloy microstructure and mechanical properties. The present study was carried out to investigate both the formability and mechanical properties of 6xxx alloy series. The slabs (7 x 11 x 1.5 cm each) were machined and homogenized for 10 h at 520 C, followed by air cooling. The results show that a -iron phase displays low formability and hinders deformation of the grains during cold rolling and leads to premature cracking. The cold rolled structure contains elongated grains with broken -Al5FeSi platelet fragments. In the Mn-containing alloy, the -iron phase is more easily deformable while addition of Sr does not improve the alloy behavior. With beryllium additions, the iron intermetallics precipitate in the form of small, globular -Al8Fe2SiBe script particles, in the interdendritic regions."
Download or read book Precipitation Hardening written by John Wilson Martin and published by . This book was released on 1968 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nanomaterials by Severe Plastic Deformation written by Michael J. Zehetbauer and published by John Wiley & Sons. This book was released on 2006-03-06 with total page 872 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings of the "Second International Conference on Nanomaterials by Severe Plastic Deformation" review the enormous scientific avalanche that has been developing in the field over recent years. A valuable resource for any scientist and engineer working in this emerging field of nanotechnology.
Download or read book Extrusion of Aluminium Alloys written by T. Sheppard and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years the importance of extruded alloys has increased due to the decline in copper extrusion, increased use in structural applications, environmental impact and reduced energy consumption. There have also been huge technical advances. This text provides comprehensive coverage of the metallurgical, mathematical and practical features of the process.
Download or read book Precipitation in Al Zn Mg Cu Alloys Modified With Sc and Zr During Aging Preprint written by and published by . This book was released on 2006 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper was developed under a SBIR contract. The effect of Sc additions on precipitation strengthening in AI-Zn-Mg-Cu alloys was studied after natural and artificial aging. Phase analysis was performed using transmission electron microscopy and computer simulations. Microhardness of the alloys was studied after different steps of aging and the strengthening mechanisms were discussed. It was found that Sc does not affect the kinetics of aging at room temperature, which is controlled by formation and growth of GPI zones. Sc also does not affect the kinetics of aging at 150C, which is controlled by formation and growth of eta' and eta particles. However, the additions of Sc accelerate the aging process at l20C within a period of time of formation and growth of GPII zones. It is concluded that the presence of Sc accelerates formation and growth of GPII zones in the Al-Zn-Mg-Cu alloys during artificial aging.
