Download or read book Size Effects and Deformation Mechanisms in Nanoscale Metallic Multilayered Composites written by Firas Akasheh and published by . This book was released on 2007 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work, size effects and deformation mechanisms in nanoscale metallic multilayered (NMM) composites were studied. Existing models for the prediction of the dependence of strength of NMM composites on the individual layer thickness do not capture the experimentally observed dependence. Dislocation interactions have been suggested as a significant contributor to this discrepancy. Due to the complexity and multiplicity of dislocation interaction in real systems, the study started by examining the hardening effect and implications on the dislocation structure of two known-to-be significant dislocation interactions in NMM composites. The first is the interaction between a threading dislocation and orthogonally intersection interfacial dislocations. Dislocation dynamics (DD) analysis was employed and it was found that the strongest interaction occurs when the interacting dislocations are collinear and involves annihilation reactions and the formation of 90° dislocation bends at the interfaces, as commonly observed in experiments. The strength predictions indicate a strengthen increase of about 50%; however, they do not follow the experimentally observed trend. The second interaction to study was that between a threading dislocation and parallel interfacial dislocations. A semi-analytical energetic approach was employed and it was found that parallel interactions can lead to softening effect, as well as hardening effect depending on the relative sign of the Burgers vector of the threading and the parallel dislocations. It was also found that when the Burgers vectors are collinear, the interaction is stronger. A comparison with the measured strength of real multilayered system shows that accounting for parallel interactions improves the strength predictions for an isolated glide dislocation, however that does not offer answers regarding the observed strength saturation when the individual layer thickness in the few nanometer range. Finally, large-scale DD simulations of NMM composites were performed. Such simulations naturally accounts for all the possible and complex interactions in a real system. The strength predictions of such simulations are in better qualitative agreement with experimental trends than any of the unit process. Nevertheless, more work is needed to validate the results by investigating different relaxation models to accomplish the initial dislocations structure used in subsequent loading. The simulations were also valuable in identifying dislocation mechanisms which can take place during the deformation.

Download or read book Atomistic Studies of Deformation Mechanisms in Nanoscale Multilayered Metallic Composites written by Shuai Shao and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this thesis is to understand the interaction between dislocations and various metallic interfaces in nanoscale metallic multilayers (NMM). At lower strain rates, this mean understanding the effect of interfaces to the strain hardening of the NMMs; at higher strain rates, this means the effect of the interfaces on the spallation strengths of the NMMs. NMMs possess ultra-high strength level which is owing to the interactions between single dislocations (i.e. no pile-up) and interfaces. In this thesis, aiming at the goal, using atomistic simulations several nanoscale metallic multilayers subjected to different loading conditions and strain rates are being considered.

Download or read book Multiscale Modelling and Simulation of Deformation and Strength of Nanoscale Metallic Multilayer Systems written by Niaz Abdolrahim and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this research is to investigate the deformation behaviors of two types of NMMs at lower length scales: 1) One dimensional Cu-Ni, Au-Ni nanowires with coherent interfaces and 2) Two dimensional Cu-Nb multilayers with incoherent interfaces.

Download or read book Principles of Extreme Mechanics XM in Design for Reliability DfR written by Arief Suriadi Budiman and published by Springer Nature. This book was released on 2021-11-13 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses issues pertinent to mechanics and stress generation, especially in recent advanced cases of technology developments, spanning from micrometer interconnects in solar photovoltaics (PV), next-gen energy storage devices to multilayers of nano-scale composites enabling novel stretchable/flexible conductor technologies. In these cases, the mechanics of materials have been pushed to the extreme edges of human knowledge to enable cutting-edge, unprecedented functionalities and technological innovations. Synchrotron X-ray diffraction, in situ small-scale mechanical testing combined with physics-based computational modeling/simulation, has been widely used approaches to probe these mechanics of the materials at their extreme limits due to their recently discovered distinct advantages. The techniques discussed in this manuscript are highlights specially curated from the broad body of work recently reported in the literature, especially ones that the author had led the pursuits at the frontier himself. Extreme stress generation in these advanced material leads to often new failure modes, and hence, the reliability of the final product is directly affected. From the recent topics and various advanced case studies covered in this book, the reader gets an updated knowledge of how new mechanics can and has been applied in Design-for-Reliability (DfR) for some of the latest technological innovations known in our modern world. Further, this also helps in building better designs, which may avoid the pitfalls of the current practiced trends.

Download or read book Investigating Deformation and Failure Mechanisms in Nanoscale Multilayer Metallic Composites written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the history of materials science there are many examples of materials discoveries that have made superlative materials; the strongest, lightest, or toughest material is almost always a goal when we invent new materials. However, often these have been a result of enormous trial and error approaches. A new methodology, one in which researchers design, from the atoms up, new ultra-strong materials for use in energy applications, is taking hold within the science and engineering community. This project focused on one particular new classification of materials; nanolaminate metallic composites. These materials, where two metallic materials are intimately bonded and layered over and over to form sheets or coatings, have been shown over the past decade to reach strengths over 10 times that of their constituents. However, they are not yet widely used in part because while extremely strong (they don't permanently bend), they are also not particularly tough (they break relatively easily when notched). Our program took a coupled approach to investigating new materials systems within the laminate field. We used computational materials science to explore ways to institute new deformation mechanisms that occurred when a tri-layer, rather than the more common bi-layer system was created. Our predictions suggested that copper-nickel or copper-niobium composites (two very common bi-layer systems) with layer thicknesses on the order of 20 nm and then layered 100's of times, would be less tough than a copper-nickel-niobium metallic composite of similar thicknesses. In particular, a particular mode of permanent deformation, cross-slip, could be activated only in the tri-layer system; the crystal structure of the other bi-layers would prohibit this particular mode of deformation. We then experimentally validated this predication using a wide range of tools. We utilized a DOE user facility, the Center for Integrated Nanotechnology (CINT), to fabricate, for the first time, these tri-layer composites. CINT formed nanolaminate composites were tested in tension, with bulge testing, using nanoindentation, and using micro-compression testing to demonstrate that the tri-layer films were indeed tougher and hardened more during deformation (they got stronger as we deformed them) than equivalent bi-layers. The seven graduate students, 4 post-docs and research faculty, and the two faculty co-PI's were able to create a collaborated computational prediction and experimental validation team to demonstrate the benefits of this class of materials to the community. The computational work crossed from atomistic to bulk simulations, and the experiments coupled form nm-scale to the mm scale; closely matching the simulations. The simulations provided viable mechanisms that explained the observed results, and new experimental results were used to push the boundaries of the simulation tools. Over the life of the 7 years of this program we proved that tri-layer nanolaminate metallic composite systems exceeded the mechanical performance of bi-layer systems if the right materials were chosen, and that the mechanism responsible for this was tied to the cross slip of dislocations. With 30 journal publications resulting from this work we have broadly disseminated this family of results to the scientific community.

Download or read book Handbook of Nanomaterials Properties written by Bharat Bhushan and published by Springer Science & Business Media. This book was released on 2014-03-13 with total page 1467 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanomaterials attract tremendous attention in recent researches. Although extensive research has been done in this field it still lacks a comprehensive reference work that presents data on properties of different Nanomaterials. This Handbook of Nanomaterials Properties will be the first single reference work that brings together the various properties with wide breadth and scope.

Download or read book TMS 2015 144th Annual Meeting and Exhibition written by The Minerals, Metals & Materials Society (TMS) and published by John Wiley & Sons. This book was released on 2015-02-26 with total page 1584 pages. Available in PDF, EPUB and Kindle. Book excerpt: The TMS 2015 Annual Meeting Supplemental Proceedings is a collection of papers from the TMS 2015 Annual Meeting & Exhibition, held March 15-19 in Orlando, Florida, USA. The papers in this volume represent 33 symposia from the meeting. This volume, along with the other proceedings volumes published for the meeting, and archival journals, such as Metallurgical and Materials Transactions and Journal of Electronic Materials, represents the available written record of the 73 symposia held at TMS2015. This proceedings volume contains both edited and unedited papers; the unedited papers have not necessarily been reviewed by the symposium organizers and are presented "as is." The opinions and statements expressed within the papers are those of the individual authors only, and no confirmations or endorsements are intended or implied.

Download or read book Micro and Nanomechanics Volume 5 written by La Vern Starman and published by Springer. This book was released on 2016-09-16 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt: Micro-and Nanomechanics, Volume 5 of the Proceedings of the 2016 SEM Annual Conference & Exposition on Experimental and Applied Mechanics, the fifth volume of ten from the Conference, brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on a wide range of areas, including: MEMS: Materials & Interfaces Microscale & Microstructural Effects on Mechanical Behavior Novel Nano-scale Probes Nanoindentation & Beyond Nanomechanics Dynamic Micro/Nano Mechanics

Download or read book Design and Development of Nanostructured Thin Films written by Antonella Macagnano and published by MDPI. This book was released on 2020-05-13 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to their unique size-dependent physicochemical properties, nanostructured thin films are used in a wide range of applications from smart coating and drug delivery to electrocatalysis and highly-sensitive sensors. Depending on the targeted application and the deposition technique, these materials have been designed and developed by tuning their atomic-molecular 2D- and/or 3D-aggregation, thickness, crystallinity, and porosity, having effects on their optical, mechanical, catalytic, and conductive properties. Several open questions remain about the impact of nanomaterial production and use on environment and health. Many efforts are currently being made not only to prevent nanotechnologies and nanomaterials from contributing to environmental pollution but also to design nanomaterials to support, control, and protect the environment. This Special Issue aims to cover the recent advances in designing nanostructured films focusing on environmental issues related to their fabrication processes (e.g., low power and low cost technologies, the use of environmentally friendly solvents), their precursors (e.g., waste-recycled, bio-based, biodegradable, and natural materials), their applications (e.g., controlled release of chemicals, mimicking of natural processes, and clean energy conversion and storage), and their use in monitoring environment pollution (e.g., sensors optically- or electrically-sensitive to pollutants)

Download or read book Deformation Mechanisms in Bioinspired Multilayered Materials written by Sina Askarinejad and published by . This book was released on 2013 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Learning lessons from nature is the key element in the design of tough and light composites. Nacre (mother of pearl) shows the nature's ability to combine strong and brittle mineral with soft organic material into a multilayered composite. In this study, mechanical bahavior and toughening mechanisms of nacre-inspired multilayered materials are explored computationally. In nacre's structure tensile pillars, shear pillars, the roughness of the tablets (or asperities) and the proteins play an important role in its overall mechanical performance. A physics-based micromechanics model for nacre is proposed to simulate the mechanical deformation in nacre and overall toughening mechanisms in the multilayered materials. The fundamental hypothesis of the model is that nanoscale shear and tensile pillars have near theoretical strength. The modeling results are in agreement with the experimental results for a microstructure similar to nacre. The results show that the volume fraction of tensile pillars affect the stiffness of material. Shear pillars determine the ultiimate strength and the asperities play the main role in ductility of the multilayered material. Although all the components of the brick and mortar structure have brittle behavior, the overall st4ructure has a ductile response. The ductile behavior of the material is a result of distributed deformation in the nacre-like structure due to existence of shear pillars and nanoasperities with near theoretical strength. Also, samples of polymer/polymer composite material with nacreous structure were made using a 3-D printer. Three-point bending test were performed on the samples and the results were analyzed and compared with the numerical models.

Download or read book TMS 2015 144th Annual Meeting Exhibition Annual Meeting Supplemental Proceedings written by The Minerals, Metals & Materials Society (TMS) and published by Springer. This book was released on 2016-12-20 with total page 1496 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Identifying Deformation and Strain Hardening Behaviors of Nanoscale Metallic Multilayers Through Nano wear Testing written by and published by . This book was released on 2016 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: In complex loading conditions (e.g. sliding contact), mechanical properties, such as strain hardening and initial hardness, will dictate the long-term performance of materials systems. With this in mind, the strain hardening behaviors of Cu/Nb nanoscale metallic multilayer systems were examined by performing nanoindentation tests within nanoscratch wear boxes and undeformed, as-deposited regions. Both the architecture and substrate influence were examined by utilizing three different individual layer thicknesses (2, 20, and 100 nm) and two total film thicknesses (1 and 10 [mu]m). After nano-wear deformation, multilayer systems with thinner layers showed less volume loss as measured by laser scanning microscopy. Additionally, the hardness of the deformed regions significantly rose with respect to the as-deposited measurements, which further increased with greater wear loads. Strain hardening exponents for multilayers with thinner layers (2 and 20 nm, n ≈ 0.018 and n ≈ 0.022 respectively) were less than was determined for 100 nm systems (n ≈ 0.041). These results suggest that singledislocation based deformation mechanisms observed for the thinner systems limit the extent of achievable strain hardening. This conclusion indicates that impacts of both architecture strengthening and strain hardening must be considered to accurately predict multilayer performance during sliding contact across varying length scales.

Download or read book Radiation Damage in Materials written by Yongqiang Wang and published by MDPI. This book was released on 2020-12-28 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: The complexity of radiation damage effects in materials that are used in various irradiation environments stems from the fundamental particle–solid interactions and the subsequent damage recovery dynamics after the collision cascades, which involves multiple length and time scales. Adding to this complexity are the transmuted impurities that are unavoidable from accompanying nuclear processes. Helium is one such impurity that plays an important and unique role in controlling the microstructure and properties of materials used in fast fission reactors, plasma-facing and structural materials in fusion devices, spallation neutron target designs, actinides, tritium-containing materials, and nuclear waste. Their ultra-low solubility in virtually all solids forces He atoms to self-precipitate into small bubbles that become nucleation sites for further void growth under radiation-induced vacancy supersaturations, resulting in material swelling and high-temperature He embrittlement, as well as surface blistering under low-energy and high-flux He bombardment. This Special Issue, “Radiation Damage in Materials—Helium Effects”, contains review articles and full-length papers on new irradiation material research activities and novel material ideas using experimental and/or modeling approaches. These studies elucidate the interactions of helium with various extreme environments and tailored nanostructures, as well as their impact on microstructural evolution and material properties.

Download or read book Multi scale Effects on Deformation Mechanisms of Polymer Nanocomposites written by Yu Dong and published by . This book was released on 2008 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bioinspired Structures and Design written by Wole Soboyejo and published by Cambridge University Press. This book was released on 2020-09-17 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: Master simple to advanced biomaterials and structures with this essential text. Featuring topics ranging from bionanoengineered materials to bio-inspired structures for spacecraft and bio-inspired robots, and covering issues such as motility, sensing, control and morphology, this highly illustrated text walks the reader through key scientific and practical engineering principles, discussing properties, applications and design. Presenting case studies for the design of materials and structures at the nano, micro, meso and macro-scales, and written by some of the leading experts on the subject, this is the ideal introduction to this emerging field for students in engineering and science as well as researchers.

Download or read book The Effects of Length Scale on the Deformation Behavior of Metallic Multilayers Part II written by and published by . This book was released on 2002 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt: The experimental observations described in a companion presentation of the same title by Misra et al. highlight that unique, non-bulk rolling textures are achieved in nanoscale multilayered thin films. Specifically, Cu/Nb multilayers deposited with an initial Kudjumov-Sachs orientation relation between Cu and Nb grains and with an initial individual layer thickness of 75nm preserve that relation during rolling. In contrast, samples with micron-scale individual layer thickness do not. To help understand this layer-dependent response, a crystal plasticity model is presented in which the Cu and Nb phases respond by slip on {l_brace}111{r_brace}/110 systems in the fcc Cu case, and {l_brace}110{r_brace} / 111 systems in the bcc Nb phase. Grains within each layered phase are required to plastically deform by a reduction in thickness and corresponding elongation in the rolling direction, with zero plastic strain along the transverse axis. The model also adopts the observation for nano-scale multilayers that the Kudjumov-Sachs orientation relation is preserved; in particular, the e 1 11> Cu and e1 10> Nb directions remain parallel to the interface normal during rolling. The crystal plasticity model then furnishes the minimum plastic work to deform a grain, as a function of grain orientation. For Cu grains, the plastic work is invariant of grain orientation, provided the critical resolved shear stress is uniform on all fcc slip systems. However, the corresponding plastic work in Nb grains is very dependent on grain orientation and has a strong minimum. This large anisotropy serves as a driving force for Nb grains to rotate around their 110 interface normal, toward the minimum. The resulting prediction for rolling texture in Nb layers agrees well with experimental observations in nanoscale Cu/Nb multilayers.

Download or read book Computational Methods for Microstructure Property Relationships written by Somnath Ghosh and published by Springer Science & Business Media. This book was released on 2010-11-17 with total page 669 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational Methods for Microstructure-Property Relationships introduces state-of-the-art advances in computational modeling approaches for materials structure-property relations. Written with an approach that recognizes the necessity of the engineering computational mechanics framework, this volume provides balanced treatment of heterogeneous materials structures within the microstructural and component scales. Encompassing both computational mechanics and computational materials science disciplines, this volume offers an analysis of the current techniques and selected topics important to industry researchers, such as deformation, creep and fatigue of primarily metallic materials. Researchers, engineers and professionals involved with predicting performance and failure of materials will find Computational Methods for Microstructure-Property Relationships a valuable reference.