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 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 Metallic Amorphous Alloy Reinforcements in Light Metal Matrices written by S. Jayalakshmi and published by Springer. This book was released on 2015-02-24 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents cutting-edge research on the design and development of novel, advanced high-strength, light-weight materials via the incorporation of novel reinforcements, namely, metallic amorphous alloys/bulk metallic glasses (BMG), in light metal matrix composites (LMMCs) based on Al and Mg. The book begins with an introduction to conventional ceramic reinforced light metal matrix composites, along with the major drawbacks which limit their application. Metallic amorphous alloys/Bulk Metallic Glasses (BMG) are new class of metallic materials that are distinctly differently from conventional metals/alloys in terms of their structure and thermal behavior, and exhibit extremely high strength (1 to 2 GPa) and large elastic strain limit (1 to 2%). Given these unique properties, upon their incorporation into Al/Mg-matrices, they provide superior interfacial properties, i.e. high degree of compatibility with the matrix due to their metallic nature when compared to conventional ceramic reinforcements, and thereby significantly enhance the mechanical performance of LMMCs. Amorphous/BMG reinforced LMMCs is an emerging research field and the existing literature is meager. This book discusses the various processing methods that would be suitable for these novel materials. A comparison of mechanical properties and strengthening mechanisms of amorphous/BMG reinforced composites with those of conventional ceramic composites is presented. Future research directions and wider research potential of the novel materials are discussed, and prospective applications are highlighted. For ease of understanding and comparison, appropriate schematics, tables, and figures are provided.
Download or read book Advanced Mechanical Properties and Deformation Mechanisms of Bulk Nanostructured Materials written by Yong Hao Zhao and published by Trans Tech Publications Ltd. This book was released on 2011-05-17 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Special topic volume with invited peer reviewed papers only
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 0 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 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 Solid State Synthesis of Magnesium Based Functional Alloys and Compounds written by Tatsuhiko Aizawa and published by Trans Tech Publications Ltd. This book was released on 2009-02-20 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume is indexed by Thomson Reuters BCI (WoS). Since the mid-nineties, magnesium-based alloys and compounds have been revisited in the hope that they will yield light functional materials. In this third wave of research and development of magnesium-based hydrogenstorage and thermoelectric materials, new factors have become important in addition to the improvement of their properties and performance. The move to reduce environmental damage requires the assurance of non-toxicity and energy-saving during manufacture. For example, the use of lead or bismuth additions must be avoided. Furthermore, due to the diminishing sources of antimony, tellurium and rare-earth elements, only metallic and non-metallic elements having a large Clerk number should be used for production. In order to compensate for these restraints, nano-technological innovation is urgently required; not only in optimum material design but also in material processing, manufacturing and device production, in order to achieve significant energy and cost savings.
Download or read book On the Microstructure and Behavior of a Nanostructured High Strength Aluminum Alloy with Solid Solution Strengthening written by Gregory Ng and published by . This book was released on 2007 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Strength and Thermally Stable Nanostructured Magnesium Alloys and Nanocomposites written by Yuan-Wei Chang and published by . This book was released on 2015 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnesium and its alloys are currently in the spotlight of global research because of the need to limit energy consumption and reduce the environmental impact. In particular, their low densities compared to other structural metals make them a very attractive alternative in the automobile and aerospace industries. However, their low strength compared to other structural materials (e.g. Al and steels) has limited their widespread application. This dissertation presents the results of developing and investigation of a high strength nanostructured magnesium-aluminum alloy and composite. The nanostructured magnesium alloy is prepared by cryomilling and consolidated by spark-plasma-sintering. Focused ion beam is used to prepare micropillars with different diameters ranging from 1.5 to 8 μm and micro-compression test is conducted by nanoindenter in order to evaluate the mechanical properties. The yield strength obtained in the present study is around three times higher than conventional magnesium alloys (120 MPa vs. 370 MPa). The yield strength of the nanostructured magnesium alloy is further improved through hot extrusion, resulting in a yield strength of 550 MPa and an ultimate strength of 580 MPa. The nanostructured magnesium alloy exhibits a strong size-dependence, and a significant improvement in strength is observed when the pillar diameter is reduced to below 3.5 μm. The deformation mechanisms of the compressed pillars were characterized using transmission electron microscopy. The size-induced strengthening is attributed to a less number of dislocation sources along with a higher activity of non-basal deformation mechanisms. We have also developed a high strength and thermally stable nanostructured magnesium composite by adding diamantane. A yield strength of 500 MPa is achieved, moreover, excellent thermal stability is demonstrated in the magnesium alloy containing diamantanes. The strength and grain size are thermally stable after annealing at 400°C for 100 hours. In contrast, the yield strength of the alloy without diamantanes decreases significantly after annealing due to severe grain growth. These results suggest that diamantanes are pinning the grain boundaries and inhibiting grain growth at elevated temperatures. Finally, molecular dynamics simulations and finite element analysis are used to explore the deformation mechanisms of magnesium with different grain sizes at atomic resolutions and correct tapering effect on micro-compression test, respectively. The results in the dissertation show that nanostructured Mg-Al alloy and Mg-Al-Diamantane composite are promising materials for aerospace and automobile industries.
Download or read book Bulk Metallic Glasses written by C. Suryanarayana and published by CRC Press. This book was released on 2017-11-22 with total page 543 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reflecting the fast pace of research in the field, the Second Edition of Bulk Metallic Glasses has been thoroughly updated and remains essential reading on the subject. It incorporates major advances in glass forming ability, corrosion behavior, and mechanical properties. Several of the newly proposed criteria to predict the glass-forming ability of alloys have been discussed. All other areas covered in this book have been updated, with special emphasis on topics where significant advances have occurred. These include processing of hierarchical surface structures and synthesis of nanophase composites using the chemical behavior of bulk metallic glasses and the development of novel bulk metallic glasses with high-strength and high-ductility and superelastic behavior. New topics such as high-entropy bulk metallic glasses, nanoporous alloys, novel nanocrystalline alloys, and soft magnetic glassy alloys with high saturation magnetization have also been discussed. Novel applications, such as metallic glassy screw bolts, surface coatings, hyperthermia glasses, ultra-thin mirrors and pressure sensors, mobile phone casing, and degradable biomedical materials, are described. Authored by the world’s foremost experts on bulk metallic glasses, this new edition endures as an indispensable reference and continues to be a one-stop resource on all aspects of bulk metallic glasses.
Download or read book Deformation induced Synthesis of Amorphous Alloys written by Rainer J. Hebert and published by . This book was released on 2003 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ultrafine Grained Materials II written by Yuntian Theodore Zhu and published by John Wiley & Sons. This book was released on 2013-09-25 with total page 886 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of a symposium sponsored by the Shaping and Forming Committee of the Materials Processing and Manufacturing Division (MPMD) and the Mechanical Behavior Committee (Jt. SMD/ASM-MSCTS) of the Structural Materials Division (SMD) of TMS (The Minerals, Metals & Materials Society) and held during the 2002 TMS Annual Meeting in Seattle, Washington February 17-21,2002.
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 Enhancement of Grain Refined Microstructure in a Nanostructured Metals Via Ultrahigh Pressure Hydrostatic Consolidation Process Construction of Master Sintering Curve MSC and Its Application to Densification of Al Mg Alloy written by and published by . This book was released on 2010 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Previously Al-Mg alloy was densified by hot isostatic processing and subsequently consolidated by hydrostatic extrusion. Through this process high strength and high formability nanostructured bulk Al-Mg alloy was fabricated. However, it is important to handle parametric control in powder metallurgical processing in terms of relative density, which is closely associated with its mechanical properties in acquiring a material of a desired property. At current stage processing parameter of density function is not controllable. In this study a concept of Master Sintering Curve (MSC) theory was introduced and applied to the examined material during densification to obtain a unified MSC allowing for predicting density variation in terms of only sintering time and temperature in regardless of thermal history at certain compaction pressure. After completing MSC new experimental set of time-temperature data were fitted to validate the derived MSC curve in such a way that it is completely coincident with new set of experimental data in tolerable error. Hardness measurement was conducted to study the effect of heating rates.
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 Microstructural and Mechanical Properties of a Solid State Additive Manufactured Magnesium Alloy written by Thomas Wilkes Robinson and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, additive manufacturing (AM) has gained prominence in rapid prototyping and production of structural components with complex geometries. Magnesium alloys, whose strength-to-weight ratio is superior compared to steel and aluminum alloys, have shown potential in lightweighting applications. However, commercial beam-based AM technologies have limited success with magnesium alloys due to vaporization and hot cracking. Therefore, as an alternative approach, we propose the use of a near net-shape solid-state additive manufacturing process, Additive Friction Stir Deposition (AFSD), to fabricate magnesium alloys in bulk. In this study, a parametric investigation was performed to quantify the effect of process parameters on AFSD build quality including volumetric defects and surface quality in magnesium alloy AZ31. In order to understand the effect of the AFSD process on structural integrity in the magnesium alloy AZ31, in-depth microstructure and mechanical property characterization was conducted on a bulk AFSD build fabricated with optimized process parameters. Results of the microstructure analysis of the as-deposited AFSD build revealed bulk microstructure similar to wrought magnesium alloy AZ31 plate. Additionally, similar hardness measurements were found in AFSD build compared to control wrought specimens. While tensile test results of the as-deposited AFSD build exhibited a 20 percent drop in yield strength, nearly identical ultimate strength was observed compared to the wrought control. The experimental results of this study illustrate the potential of using the AFSD process to additively manufacture Mg alloys for load bearing structural components with achieving wrought-like microstructure and mechanical properties.
Download or read book Deformation and Damage Process in Nanostructured Metallic Systems written by and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this reporting period, processing of nanostructured powders, consolidation of nanostructured powders, computer simulation, micro structural characterization, and mechanical deformation tests were carried out. The nanostructured powders and bulk nanostructured materials were produced successfully via optimization of processing parameters. The observed highly grain stability can be explained by a grain boundary pinning mechanism arising from the dispersoid particles as well as impurity segregation. The microstructures of the as- extruded and the deformed bulk nanocrystalline aluminum alloys were investigated using transmission electron microscopy. A nanoindentation technique and traditional mechanical tests as well as computer simulation were also used to evaluate the mechanical performance. A discrete dislocation dynamics model has been developed to bridge the gap between atomic simulations and continuum approaches. It has the potential to provide a rigorous description of the complex relationships between the macroscopic mechanical behavior of materials and the underlying fundamental physical mechanisms. The tensile test results showed that grain size effects, solid solution strengthening, Orowan strengthening and dislocation strengthening contribute significantly to the properties of the cryomilled Al alloys. The future work for the next period is also discussed in the report.
