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 Deformation Induced Solid State Amorphization in a Nanostructured Al Mg Alloy Processed by High Pressure Torsion written by and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Nanostructured Metals and Alloys written by S H Whang and published by Elsevier. This book was released on 2011-03-22 with total page 840 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tensile strength, fatigue strength and ductility are important properties of nanostructured metallic materials, which make them suitable for use in applications where strength or strength-to-weight ratios are important. Nanostructured metals and alloys reviews the latest technologies used for production of these materials, as well as recent advances in research into their structure and mechanical properties.One of the most important issues facing nanostructured metals and alloys is how to produce them. Part one describes the different methods used to process bulk nanostructured metals and alloys, including chapters on severe plastic deformation, mechanical alloying and electrodeposition among others. Part two concentrates on the microstructure and properties of nanostructured metals, with chapters studying deformation structures such as twins, microstructure of ferrous alloys by equal channel angular processing, and characteristic structures of nanostructured metals prepared by plastic deformation. In part three, the mechanical properties of nanostructured metals and alloys are discussed, with chapters on such topics as strengthening mechanisms, nanostructured metals based on molecular dynamics computer simulations, and surface deformation. Part four focuses on existing and developing applications of nanostructured metals and alloys, covering topics such as nanostructured steel for automotives, steel sheet and nanostructured coatings by spraying.With its distinguished editor and international team of contributors, Nanostructured metals and alloys is a standard reference for manufacturers of metal components, as well as those with an academic research interest in metals and materials with enhanced properties.
Download or read book Precipitation Hardening written by J. W. Martin and published by Butterworth-Heinemann. This book was released on 2012-12-02 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt: Precipitation Hardening (or age-hardening) is an important technique for the metal-using industries. The process is used to enhance the mechanical properties of a wide range of alloys, notably those based on aluminium, but also embracing some nickel and other non-ferrous alloys as well as certain steels. It is important that the mechanisms that produce this improvement in properties are understood so that the desired properties can be optimised. This book provides a thorough treatment and grounding in the subject for the student of materials science and engineering, as well as guidance, for those using the process in industry and in research. A number of excerpts from classic papers are included, which illustrate the development of precipitation hardening from being an art to a science.Precipitation Hardening (or age-hardening) is an important technique for the metal-using industries. The process is used to enhance the mechanical properties of a wide range of alloys, notably those based on aluminium, but also embracing some nickel and other non-ferrous alloys as well as certain steels. It is important that the mechanisms that produce this improvement in properties are understood so that the desired properties can be optimised. This book provides a thorough treatment and grounding in the subject for the student of materials science and engineering, as well as guidance, for those using the process in industry and in research. A number of excerpts from classic papers are included, which illustrate the development of precipitation hardening from being an art to a science.
Download or read book Nanostructure Formation and Thermal Stability of Cu and Cu based Alloys written by Mohsen Samadi Khoshkhoo and published by . This book was released on 2015-10 with total page 127 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 Microstructure and Aging Behavior of Conventional and Nanocrystalline Al Cu Mg Alloys with Sc Additions written by Alejandro Zúñiga and published by . This book was released on 2006 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of High pressure Torsion Processing at Different Temperatures on the Microstructure and Mechanical Properties of an Al Mg Si Alloy written by Kaan Tuğcu and published by . This book was released on 2012 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Magnesium Alloys Containing Rare Earth Metals written by L.L. Rokhlin and published by CRC Press. This book was released on 2003-02-20 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnesium-based alloys containing rare-earth metals are important structural materials, as they combine low density with high-strength properties. This makes them particularly attractive for industry, especially in cases where the low weight of constructions is critical, as in aircraft and space apparatus construction. One of the remarkable feature
Download or read book Thermodynamic Modeling and Experimental Study of the Al Cr Cu Fe Mg Mn Si System written by Senlin Cui and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Aluminum alloys are extensively used in civil engineering, ship building, automotive, and aerospace industry. The requirement of improving fuel efficiency and weight reduction of vehicle triggers a resurgence of research of aluminum in automobile industry. Al 6xxx series alloys are commonly utilized as extruded materials because of their high strength, formability and ductility, weldability, corrosion resistance, and low cost. The whole chain of Al alloy component manufacturing starts from aluminum melt refining, to casting, homogenization, rolling/extrusion, and finally heat treatment. The microstructure evolution of Al alloys is controlled by both thermodynamics and kinetics. The driving forces for each processing step basically include the chemical driving force or thermodynamic driving force, the interfacial energy, the mechanical driving force, etc. Thermodynamics related to chemical reactions and phase transformations is thus of fundamental importance.The study of thermochemical properties and phase diagram of Al alloys is helpful for new Al alloy composition design and process optimization. The CALPHAD (CALculation of PHAse Diagram) approach is one of the most efficient ways to study alloy thermodynamics systematically. With a well-developed Al alloy thermodynamic database, the phase equilibria and thermodynamic properties can be calculated for complex alloy systems. As a cornerstone for the understanding of various phenomena in Al 6xxx alloys, the current work focuses on the development of a thermodynamic database for the Al-Cr-Cu-Fe-Mg-Mn-Si system via a coupled experimental and thermodynamic modeling approach. Isothermal sections in the Al rich corner of the Al-Cr-Mg system were measured at 400, 450, and 500 °C via equilibrated alloys, diffusion couples, and differential thermal analysis (DSC). The thermodynamic optimizations of the binary Al-Cr, Cu-Cr, Cu-Mg, Cr-Si, and Fe-Si systems were newly performed, and the thermodynamic descriptions of the Al-Mn, Cu-Mn, Cr-Fe, Cr-Mg, and Cr-Mn systems were revised. The ternary Al-Cu-Cr, Al-Cu-Mg, Al-Cu-Si, Al-Cr-Mg, Al-Cr-Mn, Al-Cr-Si, Cu-Fe-Cr, Cu-Fe-Mn, Cu-Mg-Si, Cr-Fe-Si, and Fe-Mg-Si systems were thermodynamically modeled, and the Al-Cu-Mn system was revised. Moreover, the quaternary Al-Cu-Mg-Si system was remodeled. The optimization or revision of the thermodynamic descriptions of all the systems were based on the current experimental results and the critically evaluated literature data including phase diagram, enthalpy of mixing, activity, Gibbs energy of formation, enthalpy of formation, standard entropy, heat capacity, etc. The liquid phase was described using the Modified Quasi-chemical Model (MQM) in pair approximation, and the Compound Energy Formalism (CEF) was utilized for the descriptions of all the solid phases. The order-disorder transitions (bcc_A2/bcc_B2 transition and bcc_B2/bcc_D03 transition) were modeled using the split compound energy formalism. A self-consistent set of thermodynamic description for the Al-Cr-Cu-Fe-Mg-Mn-Si system was obtained by combining the currently assessed thermodynamic parameters with the thermodynamic parameters available in the literature. The obtained thermodynamic database was applied to investigate the recycling of Al alloys. The effect of each major and impurity alloying element on the types of precipitates and their amounts in both the solidification and equilibrium conditions were also systematically investigated for the Al 6xxx series alloys using the thermodynamic calculations with the present new database." --
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 Fundamental Investigations of Plasticity in High Strength Nanostructured Aluminum Alloys written by and published by . This book was released on 2000 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cryomilled aluminum alloys are being developed for aerospace applications. These high-strength aluminum alloys are currently targeted for low-temperature rocket applications. This research focused on the fundamental strengthening mechanisms in these alloys. The primary sources of strengthening in cryomilled aluminum alloys are dispersion of nanocrystalline particles and ultrafine grain size that form during the cryomilling stage. Optimized thermo-mechanical processing of cryomilled powder results in an ultrafine grain size material with nanocrystalline particles. This study investigated the temperature dependence of strength and ductility in these alloys. The theoretical models predict strengthening at low temperatures and decrease of flow stress with decreasing grain size because of diffusional flow and grain boundary sliding at elevated temperatures. The results from this study show discrepancies with theoretical models. Significant work hardening was observed at room temperature in both Al-Ti-Cu and Al-Mg alloys. The strain hardening exponents suggest contributions from both direct and indirect work hardening mechanisms. At elevated temperatures, the stress-strain rate data for Al-Mg alloys can be best described by a power law constitutive relationship with a stress exponent of 5 and threshold stress. However, the activation energy is very high even after compensating for threshold approach. This indicates that dissolution of Al3Mg2 precipitates influence the deformation kinetics. (6 figures, 8 refs.).
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 Optimizing Mechanical Properties and Thermal Stability of Age Hardenable Aluminum Alloys Through Theoretical Modeling Alloy Modification and Thermal Mechanical Processing written by and published by . This book was released on 2005 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: This proposal was to design and test an Al-Cu-Mg (Ag) alloy for moderate temperatures (up to 150 degrees C) application. A significant improvement in the creep resistance was primarily pursued in the program through enhancement of the yield strength and the thermal stability of the age-hardenable alloy. Major tasks have been finished as planned: 1) We identified the optimum structures of complex multiple secondary phase precipitates using dislocation slip simulation methods that we developed; focusing on Al-Cu-Mg based alloys with Cu: Mg ratios, vs. determined the omega phase as the main strengthening precipitate phase. 2) We constructed a special thermodynamic database (incorporating the metastable omega phase) to determine the absolute Cu and Mg concentration for optimum chemical driving forces of omega phase nucleation. 3) To control the formation (nucleation) of competing precipitate phases, we developed an effective and efficient approach to characterize effects of alloying elements. The computational tools, combining the state-of-the- art across-scale computational methods from first principles calculations to clustering strain analysis. We demonstrated how trace amounts of Mg and Ag additional catalyze omega phase nucleation and identified Si to be deleterious and that it must be eliminated. 4) We accordingly designed new alloys with compositions: Al -(4 to 5) Cu-(O.4 to 0.6) Mg-(O.4 to 0.06) Ag (wt%)with minimal Si content for the optimum strength and second phase thermal stabilities.
Download or read book Alloy Development for the Enhanced Stability of omega Precipitates in AL CU MG AG Alloys written by Brian M. Gable and published by . This book was released on 2004 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Processing Microstructure Evolution and Properties of Nanoscale Aluminum Alloy written by and published by . This book was released on 2005 with total page 219 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this project, phase transformations and precipitation behavior of Al-Cu nanoparticles were first studied. The nanoparticles were synthesized by a Plasma Ablation process and found to contain a 2- 5 nm thick adherent aluminum oxide scale, which prevented further oxidation. On aging, a precipitation sequence consisting of, nearly pure Cu precipitates to the metastable theta prime to equilibrium theta was observed. The structure of theta prime and its interface with the Al matrix has been characterized. Ultrafine Al-Cu nanoparticles (5-25 nm) were also synthesized by inert gas condensation and their aging behavior was studied. These particles were found to be quite stable against precipitation. Secondly, pure Al nanoparticles were prepared by the Exploding Wire process and their sintering and consolidation behavior were studied. It was found that Al nanopowders could be processed to bulk structures with high hardness and density. Sintering temperature was found to have a dominant effect on density, hardness and microstructure. Sintering at temperatures>600 degree C led to breakup of the oxide scale, leading to an interesting nanocomposite composed of 100-200 nm Al oxide dispersed in a bimodal nanometer-micrometer size Al matrix grains. And the randomly dispersed oxide fragments were quite effective in pinning the Al grain boundaries, preventing excessive grain growth and retaining high hardness. Cold rolling and hot rolling were effective methods for attaining full densification and high hardness. Thirdly, the microstructure evolution and mechanical behavior of Al-Al2O3 nanocomposites were studied. The composites can retain high strength at elevated temperature and thermal soaking has practically no detrimental effect on strength. Although the ductility of the composite remains quite low, there was substantial evidence for high localized plasticity. The strengthening mechanisms of the composite include: Orowan strengthening, grain size strengthening and forest strengthening. Finally, the microstructure evolution and mechanical behavior of 2024Al-Al2O3 nanocomposites were studied. This 2024Al-Al2O3 composite exhibits similar thermal stability and high strength at elevated temperature as Al-Al2O3. On ageing, the matrix of 2024Al-Al2O3 composites revealed a precipitation sequence of: alpha-Al to GP/GPB to Stheta prime/S prime to theta/S. The strengthening mechanisms of the 2024Al-Al2O3 composites include precipitation strengthening, Orowan strengthening, grain size strengthening and Forest strengthening.
