Amorphous metals have gained a lot of attention since its introduction in the 1960s, and the usage and knowledge are growing rapidly. The underlying reason for this trend is the desire to utilize these materials unique combinationof properties. New manufacturing techniques such as amorphous metal moulding (AMM) have enabled themanufacture of larger and more complex amorphous products in larger production volumes than before. In order to successfully implement AMM into the development and production of products, knowledge regarding its strengths and weaknesses, as well as how to relate to it when designing parts to be manufactured using the technology is needed. The objective in this master thesis was to investigate the implementation and potential gains of using amorphous alloys made with AMM, both in theory using academic research, and in practice by redesigning existing productsto be manufactured using the technology. Processes how to identify products that are suitable to manufacture and then design them for AMM were formulated. The academic research was compiled in a literature study and served as a base together with a dialog with a manufacturer to formulate these processes. The processes were then used toredesign the current fuze holder designs to accommodate the new manufacturing requirements posed by AMM. A 3D-model was designed and later analysed to provide a design with sufficient strength. It was shown that substantial volume reductions were possible but at a penalty of increased weight and cost, due to the higher density and material cost of the amorphous alloys compared to the current aluminium alloy. Furthermore, as of this writing, with the limitations that exists with the technology, it was not possible to design the fuze holders to fulfil all requirements that exist for AMM. But a small piston that is currently made of steel was shown to be possible to manufacture using AMM, which resulted in both reduced volume and weight, but also cost. In order toverify the results in this study and to progress further, a prototype should be manufactured and tested. This in order to verify both the integrity of the analysis, but also to verify that the design meets the other requirements posed onfuze holders, such as environmental and functional demands. / Amorfa metaller har fått mycket uppmärksamhet sedan deras introduktion under 1960-talet och användandet och kunskaperna ökar i snabb takt. Den bakomliggande orsaken för denna trend är viljan att utnyttja dessa materials unika kombination av egenskaper. Nya tillverkningstekniker såsom amorf metallgjutning (AMM) har möjliggjort tillverkningen av större och mer komplexa amorfa produkter i större produktionsvolymer än tidigare. För att framgångsrikt implementera AMM till utvecklingen och produktionen av produkter måste kunskap kring dess styrkor och svagheter utvärderas. Men även kunskap hur man ska förhålla sig till den när man konstruerar AMM detaljer. Målet med detta examensarbete var att undersöka genomförandet och potentiella fördelar av att använda amorfametaller gjorda med AMM både teoretiskt via akademisk forskning och i praktiken genom att omkonstruera en existerande produkt för att tillverkas med teknologin. Processer hur man identifierar produkter som är lämpliga att tillverka med AMM och sedan hur dessa ska konstrueras formulerades. Den akademiska litteraturen samlades i en litteraturstudie och användes tillsammans med en dialog med en tillverkare till att formulera dessa processer. Processerna användes sedan för att omkonstruera den nuvarande tändrörshållardesigner för att tillgodose de nya tillverkningskraven som uppstår från AMM. En 3D-modell konstruerades och analyserades sedan för att säkerställaen konstruktion med tillräcklig hållfasthet. Det visades att betydande volymminskningar var möjliga men till en följd av ökad vikt och kostnad på grund avden amorfa legeringens högre densitet och kostnad jämfört med nuvarande aluminiumlegering. Vidare demonstrerades att det vid skrivande stund inte var möjligt att tillverka tändrörshållarna med AMM på grund av teknologins nuvarande begränsningar. Dock visades att en liten kolv som i dagsläget tillverkas i stål kunde tillverkasmed AMM vilket resulterade i en minskning av volymen, massan och kostnaden. För att bekräfta resultaten i denna studie samt för att gå vidare bör en prototyp tillverkas och testas. Detta för att bekräfta både analysens integritet men även för att bekräfta att konstruktionen når upp till de andra kraven som ställs på tändrörshållare såsom miljö- och funktionskrav.

Amorphous metals have been discovered in 1960 and, because of their structures, exhibit very unique mechanical, magnetic and chemical properties that can have various applications. These properties qualify them as the potential material of the future. This work focuses on a new laser ablation technique to synthesize nanoparticles of amorphous metals from aqueous feedstock. One of the critical factors in the production of amorphous metal is the cooling rate used to synthesize them. The laser ablation of microparticle aerosol (LAMA) process used in this work, with a cooling rate estimated of 10¹² K/s, has all the characteristics required for the production of such metallic glasses. A Collison nebulizer is used to generate microdroplets of a nitrate solution containing the corresponding ratio of metals for the production of a Zr-Al-Ni based alloy. Once dried and conditioned, these microdroplets leave solid microparticles which are ablated by an excimer laser producing nanoparticles that are then filtered by virtual impaction. In order to characterize the nanoparticles obtained with this process nanoparticulate films produced by LAMA have been analyzed by optical profilometry, scanning electron microscopy (SEM) equipped with energy-dispersive x-ray spectroscopy (EDS) and transmission electron microscopy (TEM) equipped with EDS. The results agree with a hypothesis that the films contain oxidized, amorphous metal on the surface of the films. When the films are thin, they are fully oxidized, and simultaneous segregation of Zr occurs to the surface. The hypothesis and the results are discussed. / text

Fitas amorfas ferromagnéticas apresentam um decaimento com o tempo da susceptibilidade magnética. Tal fenômeno é conhecido como aftereffect ou desacomodação (DA). Para explicar esse fenômeno em ligas amorfas existem dois modelos importantes. O modelo de Allia e Vinai prevê uma dependência do decaimento relativo da permeabilidade A?/? com a magnetostricção de saturação ?s. Construímos um sistema de medidas adequado para realizar tais experimentos. Fabricamos e caracterizamos magneticamente três séries de composições Co77-x MnxSi14B9 (série 1: x = O, 2, 4, 5, 6, 7, 8, 9; série 2: x = 0, 2, 4, 6, 8, 10, 15); Co75-xMnx Fe1Mo1Si14B9 (série 3: 1, 3, 4, 5, 6, 7). Preocupados em evitar a dispersão de dados frequentemente observada na literatura, mantivemos os parâmetros de fabricação da fita constantes, bem como também a proporção de metalóides. Apesar dos cuidados, nossos resultados ainda apresentaram certa dispersão. Mesmo assim, foi possível concluir que nossos resultados são bem descritos pelo modelo. A caracterização magnética das fitas de Co-Mn e o estudo da dependência da DA com ?s nessas ligas deram origem a um artigo que se tornou nosso primeiro trabalho publicado em revista internacional. O modelo proposto por Kronmüllerer dá maior ênfase à cinética dos processos responsáveis pelo decaimento da susceptibilidade. Por isso foi necessário construir um novo sistema que nos permitisse realizar medidas em diferentes temperaturas. Realizamos medidas de desacomodação em Co67Fe4Mo1Si12B16. Conseguimos eliminar as contribuições irreversíveis da DA através de um tratamento térmico seguido de um processo de estabilização. Os resultados das medidas de DA foram ajustados de acordo com a expressão prevista pelo modelo, fornecendo um valor de ?0 ~ 10-12 segundos, que é da ordem do inverso da frequência de Debye nesses materiais. Concluímos que os dois modelos estudados são igualmente úteis no estudo da desacomodação e devem ser tratados como aspectos complementares do mesmo problema. / Amorphous ferromagnetic alloys show a decay of magnetic susceptibility. This phenomenon is known as aftereffect or disaccomodation (DA). There are two major models which explain this effect in amorphous materials. According to Allia et al., the decay of susceptibility presents a dependence on the saturation magnetostriction ?s. We built an adequate system for measurement of DA based on this model. Ribbons of compositions: Co77-x MnxSi14B9 (series 1: x = O, 2, 4, 5, 6, 7, 8, 9; series 2: x = 0, 2, 4, 6, 8, 10, 15); Co75-xMnx Fe1Mo1Si14B9 (series 3: 1, 3, 4, 5, 6, 7), were produced by melt-spinning. Production parameters were held constant as well as the metalloid concentration in order to prevent the data dispersion which is commonly observed in the literature. Despite our cane, results show a certain dispersion, although it is possible to confirm the validity of this model in describing such alloys The magnetic characterization and study of the dependence of DA on ?s on these alloys originated our first international publication. Kronmülller proposes another model which emphasizes the kinetics of the processes originating such decay. We built another system which allows measurements at, higher temperatures. Measurements were made in Co67Fe4Mo1Si12B16. Irreversible contributions were eliminated by a heat treatment followed by a stabilization process. Fitting of the resulting data to the theoretical expression yields a value of ?0 ~ 10-12 s, which corresponds in order of magnitude to the inverse of Debye frequency in these materials. We conclude that both models are useful in the study of DA in amorphous and should be treated as complementary aspects of the same problem.

Fitas amorfas ferromagnéticas apresentam um decaimento com o tempo da susceptibilidade magnética. Tal fenômeno é conhecido como aftereffect ou desacomodação (DA). Para explicar esse fenômeno em ligas amorfas existem dois modelos importantes. O modelo de Allia e Vinai prevê uma dependência do decaimento relativo da permeabilidade A?/? com a magnetostricção de saturação ?s. Construímos um sistema de medidas adequado para realizar tais experimentos. Fabricamos e caracterizamos magneticamente três séries de composições Co77-x MnxSi14B9 (série 1: x = O, 2, 4, 5, 6, 7, 8, 9; série 2: x = 0, 2, 4, 6, 8, 10, 15); Co75-xMnx Fe1Mo1Si14B9 (série 3: 1, 3, 4, 5, 6, 7). Preocupados em evitar a dispersão de dados frequentemente observada na literatura, mantivemos os parâmetros de fabricação da fita constantes, bem como também a proporção de metalóides. Apesar dos cuidados, nossos resultados ainda apresentaram certa dispersão. Mesmo assim, foi possível concluir que nossos resultados são bem descritos pelo modelo. A caracterização magnética das fitas de Co-Mn e o estudo da dependência da DA com ?s nessas ligas deram origem a um artigo que se tornou nosso primeiro trabalho publicado em revista internacional. O modelo proposto por Kronmüllerer dá maior ênfase à cinética dos processos responsáveis pelo decaimento da susceptibilidade. Por isso foi necessário construir um novo sistema que nos permitisse realizar medidas em diferentes temperaturas. Realizamos medidas de desacomodação em Co67Fe4Mo1Si12B16. Conseguimos eliminar as contribuições irreversíveis da DA através de um tratamento térmico seguido de um processo de estabilização. Os resultados das medidas de DA foram ajustados de acordo com a expressão prevista pelo modelo, fornecendo um valor de ?0 ~ 10-12 segundos, que é da ordem do inverso da frequência de Debye nesses materiais. Concluímos que os dois modelos estudados são igualmente úteis no estudo da desacomodação e devem ser tratados como aspectos complementares do mesmo problema. / Amorphous ferromagnetic alloys show a decay of magnetic susceptibility. This phenomenon is known as aftereffect or disaccomodation (DA). There are two major models which explain this effect in amorphous materials. According to Allia et al., the decay of susceptibility presents a dependence on the saturation magnetostriction ?s. We built an adequate system for measurement of DA based on this model. Ribbons of compositions: Co77-x MnxSi14B9 (series 1: x = O, 2, 4, 5, 6, 7, 8, 9; series 2: x = 0, 2, 4, 6, 8, 10, 15); Co75-xMnx Fe1Mo1Si14B9 (series 3: 1, 3, 4, 5, 6, 7), were produced by melt-spinning. Production parameters were held constant as well as the metalloid concentration in order to prevent the data dispersion which is commonly observed in the literature. Despite our cane, results show a certain dispersion, although it is possible to confirm the validity of this model in describing such alloys The magnetic characterization and study of the dependence of DA on ?s on these alloys originated our first international publication. Kronmülller proposes another model which emphasizes the kinetics of the processes originating such decay. We built another system which allows measurements at, higher temperatures. Measurements were made in Co67Fe4Mo1Si12B16. Irreversible contributions were eliminated by a heat treatment followed by a stabilization process. Fitting of the resulting data to the theoretical expression yields a value of ?0 ~ 10-12 s, which corresponds in order of magnitude to the inverse of Debye frequency in these materials. We conclude that both models are useful in the study of DA in amorphous and should be treated as complementary aspects of the same problem.

Solid-state amorphous materials show amazing promise in thin-film electronics. The interface-to-bulk ratio of thin films makes interfacial chemistries of these systems of utmost importance. Thin films of amorphous metals, dielectrics and semiconductors have novel chemistries that are not only based upon their elemental constituent makeup, but also based upon the method with which the amorphous material is deposited and treated after deposition. The chemical attributes unique to amorphous, thin-film systems are defined primarily through the utilization of solution-processed aluminum oxide phosphate dielectric material and Zr������Cu������Al������Ni������ metal. the chemical findings wrought via the observation of interactions between amorphous metal-dielectric systems are applied to semiconductor/insulator systems to illustrate the use of the same general chemical principles applying to diverse problems. Finally in the appendices, the systems are utilized to create extremely-thin tunneling electronic devices and optical metamaterials as well as innovative classroom material. / Graduation date: 2012 / Access restricted to the OSU Community at author's request from Dec. 13, 2011 - Dec. 13, 2012

Bulk metallic glasses (BMGs) have displayed impressive mechanical properties, but the use and dimensions of material have been limited due to critical cooling rate requirements and low ductility. The application of severe plastic deformation by equal channel angular extrusion (ECAE) for consolidation of bulk amorphous metals (BAM) and amorphous metal matrix composites (AMMC) is investigated in this dissertation. The objectives of this research are a) to better understand processing parameters which promote bonding between particles and b) to determine by what mechanisms the plasticity is enhanced in bulk amorphous metal matrix composites consolidated by ECAE. To accomplish the objectives BAM and AMMCs were produced via ECAE consolidation of Vitreloy 106a (Zr58.5Nb2.8Cu15.6Ni12.8Al10.3-wt%), ARLloy #1 (Hf71.3Cu16.2Ni7.6Ti2.2Al2.6 -wt%), and both of these amorphous alloys blended with crystalline phases of W, Cu and Ni. Novel instrumented extrusions and a host of postprocessing material characterizations were used to evaluate processing conditions and material properties. The results show that ECAE consolidation at temperatures within the supercooled liquid region gives near fully dense (>99%) and well bonded millimeter scale BAM and AMMCs. The mechanical properties of the ECAE processed BMG are comparable to cast material: σf = 1640 MPa, εf = 2.3%, E = 80 GPa for consolidated Vitreloy 106a as compared to σf = 1800 MPa, εf = 2.5%, E = 85 GPa for cast Vitreloy 106, and σf = 1660 MPa, εf = 2.0%, E = 97 GPa for ARLloy #1 as compared to σf = 2150 MPa, εf < 2.5%, E = 102 GPa for Hf52Cu17.9Ni14.6Ti5Al10. The mechanical properties of AMMCs are substandard compared to those obtained from melt-infiltrated composites due to non-ideal particle bonding conditions such as surface oxides and crystalline phase morphology and chemistry. It is demonstrated that the addition of a dispersed crystalline phase to an amorphous matrix by ECAE powder consolidation increases the plasticity of the amorphous matrix by providing locations for generation and/or arrest of adiabatic shear bands. The ability of ECAE to consolidated BAM and AMMCs with improved plasticity opens the possibility of overcoming the size and plasticity limitations of the monolithic bulk metallic glasses.

Non-crystalline thin solid films are seeing increasing interest for a wide variety of applications. However, understanding structure and compositional variations in these films is an immense challenge. Conventional bulk structural or compositional characterization techniques such as X-ray diffraction often do not provide an adequate amount of information on their own. Electron microscopy is an incredibly powerful technique for structural and compositional film characterization, but is limited to inspection of only a small volume of any given sample. Rather than using one technique alone to gain information about a specimen, the greatest success is realized when these techniques are used in concert. This dissertation illustrates the idea that statistical analysis of electron microscopy data can provide information invaluable to interpreting bulk structural and compositional data from non-crystalline films. The first set of examples include demonstration of a statistical analysis method that can be applied to electron microscopy data to determine the presence of inhomogeneity along one film axis. This analysis method is applied to understanding compositional inhomogeneity that develops during formation of amorphous oxide films from aqueous solutions. Key insights are revealed that aid interpretation of bulk film X-ray characterization and possible processing conditions that lead to the compositional inhomogeneity. The second and third sets of examples describe the importance of electron microscopy analysis for structure determination in rotationally-disordered, non-epitaxial 2D heterostructures prepared from modulated elemental reactants. The second set of examples investigates the effects of nanoarchitecture on interlayer interactions and layer structure in heterostructures with interleaved BiSe and NbSe2 layers. The BiSe layers in these compounds display an interesting structural variation that impacts the overall compound properties. The structural variation is not visible using typical X-ray diffraction experiments, but analysis of electron microscopy images provides key insight into its existence. Finally, the third set of examples investigate several SnSe-containing heterostructures that provide insight into the unusual consequences of their non-epitaxial structure and film formation from modulated elemental reactants. Electron microscopy analysis, in conjunction with other characterization techniques, was invaluable for uncovering structural and compositional details within these compounds. This work contains previously published and unpublished co-authored material. / 10000-01-01

Les verres métalliques sont des matériaux récents (≈ 50 ans), obtenus par refroidissement rapide d'un alliage en fusion. La structure amorphe de ces matériaux leur confère des propriétés particulières : une très grande résistance mécanique (limite à la rupture de l'ordre de 1,7 GPa pour des alliages base Zr), une déformation élastique de l'ordre de 2% mais pas ou peu de ductilité. Les compositions pouvant être élaborées à l’état amorphe, et, sous forme massive, sont en nombre limité. Le travail présenté dans ce manuscrit démontre la possibilité de consolider par frittage SPS (Spark Plasma Sintering), des poudres amorphes obtenues par atomisation (Фmoy.≈70 μm), tout en conservant majoritairement le caractère amorphe. L’optimisation de ce protocole, avec la composition Zr57Cu20Al10Ni8Ti5, a permis de retrouver le même comportement mécanique qu’un verre massif monolithe. Une cristallisation partielle du matériau se produit cependant aux points de contact des particules, mais pourrait être réduite en poursuivant le modèle de frittage esquissé dans ce manuscrit. Aux vues de ces résultats, la conception de nouvelles compositions, et leur élaboration sous forme de rubans, ont été menées. La caractérisation par nano-indentation permet d’estimer de manière fiable les propriétés mécaniques de ces alliages. Enfin, une nouvelle méthode d’évaluation du volume d’activation, qui est le volume élémentaire cisaillé initiant la déformation plastique, est présentée. Il s’agit de l’analyse statistique d’essais de pseudo-fluage en nano-indentation, réalisés à température ambiante. En conclusion, ce travail propose de nouvelles perspectives d’élaboration de verre métalliques sous forme massive dans une gamme de composition bien plus large / The metallic glasses are relatively new materials (≈ 50 years), produced by quenching a molten alloy. The amorphous structure of these materials gives them unique properties: very high strength (fracture stress is about 1.7 GPa for Zr based alloys), an elastic deformation reaching 2%, but little or no ductility. The compositions, which could produce both amorphous and bulk samples, are limited. The work, detailed in this manuscript, shows the possibility of sintering using SPS (Spark Plasma Sintering) amorphous powders obtained by atomization (Фaverage ≈ 70 microns). The result is a fully densified and near fully amorphous sample. The optimization of this technique, with the composition Zr57Cu20Al10Ni8Ti5, gave samples for which mechanical behaviour is close to the bulk metallic glass behaviour. However, partial crystallization of the material occurs, localized at the contact points of particles, but could be reduced by deepening the sintering model outlined in this manuscript. In view of these results, new compositions are designed, and the production of ribbons was conducted. The characterization by nano-indentation estimates reliably the mechanical properties of these alloys. Finally, a new method, evaluating the activation volume, which is the elementary volume initiating plastic deformation, is presented. This technique is a statistical analysis of pseudo-creep tests performed by nano-indentation, at room temperature. In conclusion, this work opens new perspectives to develop bulk samples in broad range of compositions

The objective of this doctoral thesis is to develop, engineer and investigate an amorphous metal tungsten nitride (aWNx) and to study its functionality for applications focused on electromechanical system at the nano-scale. Charge transport based solid state device oriented complementary metal oxide semiconductor (CMOS) electronics have reached a level where they are scaled down to nearly their fundamental limits regarding switching speed, off state power consumption and the on state power consumption due to the fundamental limitation of sub-threshold slope (SS) remains at 60 mV/dec. NEM switch theoretically and practically offers the steepest sub-threshold slope and practically has shown zero static power consumption due to their physical isolation originated from the nature of their mechanical operation. Fundamental challenges remain with NEM switches in context of their performance and reliability: (i) necessity of lower pull-in voltage comparable to CMOS technology; (ii) operation in ambient/air; (iii) increased ON current and decreased ON resistance; (iv) scaling of devices and improved mechanical and electrical contacts; and (v) high endurance. The “perfect” NEM switch should overcome all the above-mentioned challenges. Here, we show such a NEM switch fabricated with aWNx to show (i) sub-0.3-volt operation; (ii) operation in air and vacuum; (iii) ON current as high as 0.5 mA and ON resistance lower than 5 kΩ; (iv) improved mechanical contact; and the most importantly (v) continuous switching of 8 trillion cycles for more than 10 days with the highest switching speed is 30 nanosecond without hysteresis. In addition, tungsten nitride could be the modern life vine by fulfilling the demand of biodegradable material for sustainable life regime. Transient electronics is a form of biodegradable electronics as it is physically disappearing totally or partially after performing the required function. The fabricated aWNx suites this category very well, despite not being a universal bio-element. It has been found that aWNx dissolves in ground water with a rate of ≈ 20-60 nm h-1. This means that a 100 nm thick aWNx disappears in ground water in less than a day and three days are enough to dissolve completely a 300 nm thickness device.

No description available.