No description available.

A construção civil é o maior consumidor de recursos naturais do planeta, apropriando-se atualmente de mais da metade da massa total dos materiais extraídos. Neste contexto, o desenvolvimento de sistemas construtivos que proporcionem uma redução do consumo de materiais, conhecida como o princípio da desmaterialização dos edifícios, pode ser uma estratégia para a redução do impacto que a construção civil exerce sobre o ambiente, e um passo em direção a uma economia mais sustentável. A utilização de placas cimentícias para a produção de vedações vem crescendo em várias partes do mundo, seja para a produção de vedações verticais externas, seja como revestimento não aderido sobre vedos existentes, destinados tanto a melhoria estética quanto o desempenho destas fachadas. Uma vedação com placas cimentícias possui em torno de 25% da massa de uma alvenaria tradicional constituída por blocos de concreto para a execução de uma mesma área de vedação vertical, o que pode contribuir ainda para uma redução dos materiais empregados nas estruturas e fundações de um edifício. Apesar da utilização destas placas cimentícias estar coerente com a estratégia da desmaterialização, algumas experiências de vedações executadas com estes componentes manifestaram problemas de manutenção de suas características ao longo do tempo, apresentando fissuras geralmente nas juntas entre placas. Verificando-se as propriedades dos materiais que constituem esta placa cimentícia, principalmente a variação dimensional em relação à temperatura e umidade, constatou-se uma incompatibilidade entre a amplitude das variações dimensionais resultantes e os sistemas de fixação e juntas empregados para a sustentação das mesmas. A avaliação experimental de choque térmico comprovou a influência destas variações para a deterioração das juntas entre as placas. Com base nesta constatação, e em análises dos processos de fixação de placas cimentícias adotados por fornecedores em diversas partes do mundo, foi desenvolvido neste trabalho um novo sistema de fixação para placas cimentícias e de juntas entre estas com capacidade de atender a esta variação dimensional. Realizaram-se protótipos destes componentes os quais foram submetidos a uma avaliação experimental de choque térmico, resultando em nenhuma alteração visível nas juntas e nas superfícies destas placas. Como resultado concluiu-se que a criação de mecanismos que possibilitem acomodação às variações dimensionais, tanto nos dispositivos de fixação destas à estrutura, quanto nos acabamentos das juntas, podem contribuir significativamente para a durabilidade do sistema de vedações constituída por placas cimentícias. / The construction industry is the largest consumer of natural resources in the planet, currently appropriating more than half of mass of the total material extracted. In this context, the development of building systems that provide their dematerialization can be considered as a strategy to reduce the environmental construction impact, and a step toward a more sustainable economy. The use of fiber cement boards for the building production is growing in many parts of the world, to produce external vertical building enclosure or building envelopes, to improving the aesthetics and performance of these facades. A fiber cement board walls weigh around 25% of the traditional masonry mass made of concrete blocks for the same area of vertical building enclosure which can further contribute to a reduction of the materials used in building structures and foundations. Although the use of fiber cement boards complies with the dematerialization strategy, some experiments carried out with these cladding showed maintenance problems over time, usually cracks in the joints between panels. Checking the properties of materials constituting fiber cement boards, especially the dimensional variation due to changing temperature and humidity, there was an incompatibility between these dimensional variations amplitude and fixing systems and joints used to support them. The thermal shock experimental evaluation proved the influence of these variations on joints deterioration. Based on this observation, and on analyzes of the fiber cement suppliers recommendations over the world, a new system for fixing fiber cement board and joints between them was developed in this work with capacity to adapt to this dimensional variation. Prototypes of these components were made and submitted the thermal shock evaluation, resulting in no visible changes in the joints and on the surfaces of these panels. As a result, it was concluded that the creation of mechanisms that allow accommodating the dimensional variations, both in fixing these panels to the structure, and in the joints finishing can significantly contribute to the vertical building enclosure system durability.

Dünne Filme aus konjugierten Molekülen werden vermehrt in der organischen Optoelektronik, Bio-Sensorik und Oberflächenmodifikationen eingesetzt. Jedoch steckt das nanoskopische Verständnis von elementaren Prozessen bzgl. des molekularen Wachstums, der Film-Stabilität und thermisch-mechanischer Eigenschaften noch in den Kinderschuhen. Im ersten Teil dieser Arbeit nutzen wir Echtzeit in situ spekulare und diffuse Röntgenstreuung in Kombination mit Kinetik-Monte-Carlo Simulationen, um die Nukleation und das Multilagen-Wachstum von C60 zu studieren. Wir quantifizieren einen konsistenten Satz von Energieparametern, die die Oberflächenprozesse während des Wachstums beschreiben: eine effektive Ehrlich-Schwoebel Barriere von EES = 110 meV, eine Oberflächendiffusions-Barriere von ED = 540 meV und die Bindungsenergie von EB = 130 meV. Durch die Analyse der Teilchendynamiken finden wir, dass die laterale Diffusion ähnlich derer von Kolloiden ist, jedoch weist die Stufenkanten-Diffusion eine atom-ähnlichen Schwoebel-Barriere auf. Außerdem haben wir für die erste Monolage ein thermisch-aktiviertes Dewetting nach dem Wachstum von C60 auf Mica mit einer effektiven Aktivierungsbarriere von (0.33 ± 0.14) eV für die Aufwärts-Diffusion beobachtet. Im zweiten Teil der Arbeit untersuchen wir die thermomechanischen Eigenschaften der supra-molekularen Anordnung von dem organischen Halbleiter PTCDI-C8. Temperaturabhängige GIXD-Experimente decken einen außergewöhnlich großen positiven und negativen thermischen Expansionskoeffizienten der Kristallstruktur auf. Die Moleküle vollführen kooperative rotierende Bewegungen als Reaktion auf die Temperaturänderung, die zu dieser anomalen thermischen Expansion führen. Unsere Beschreibung der Bewegungen einzelner adsorbierter Moleküle während des Wachstums und der kooperativen Bewegungen einzelner Moleküle in supra-molekularen Ensembles auf der molekularen Skala wird die weitere Arbeit auf dem Weg zu funktionalen molekularen dünnen Filmen beleben. / Thin films of conjugated molecules are increasingly used in organic optoelectronics, biosensing and surface modification. However, nanoscopic understanding of elementary processes regarding the molecular film growth, the stability of these films and regarding the thermal and mechanical properties of supra-molecular assemblies are in its infancy. In the first part of this thesis we use real-time in situ specular and diffuse X-ray scattering in combination with kinetic Monte Carlo simulations to study C60 nucleation and multilayer growth. We quantify a consistent set of energy parameters, which describe the surface processes during growth, yielding an effective Ehrlich-Schwoebel barrier of EES = 110 meV, a surface diffusion barrier of ED = 540 meV and a binding energy of EB = 130 meV. Analysing the particle-resolved dynamics, we find that the lateral diffusion is similar to colloids, but step-edge crossing is characterized by an atom-like Schwoebel barrier. Furthermore, a thermally-activated post-growth dewetting for C60 on mica has been observed for the first monolayer with an effective activation barrier for upward interlayer transport of (0.33 ± 0.14) eV. In the second part we investigate the thermomechanical properties of the supra-molecular assembly of the organic semiconductor PTCDI-C8. Temperature-dependent Grazing Incidence X-ray Diffraction (GIXD) experiments reveal extraordinary large positive and, surprisingly, negative thermal expansion coefficients of the thin film crystal structure. The molecules perform temperature-controlled cooperative rotational motions leading to the change of the molecular crystal structure at different temperatures. We hope that our molecular scale picture of the movement of single ad-molecules during growth and the cooperative motions of single molecules in supra-molecular ensembles will stimulate further work towards the optimized, rational design of functional molecular thin films and nanomaterials.

In the present study the results of investigations on polycrystalline MgB2 and on single crystals of YNi2B2C and HoNi2B2C are presented. In particular, measurementes of specific electrical resistance, thermal conductivity, thermoelectric power, and of the linear thermal expansion coefficient were performed. Moreover, the specific heat of polycristalline borocarbide samples was evaluated. From the measured data, the temperature dependencies of the Lorenz number and of the Grueneisen parameter can be determined, also the pressure dependence of the superconducting transition temperature using the Ehrenfest relation. At low temperatures a characteristic deviation of the resistivity from the Bloch-Grueneisen law in the normal state for all investigated substances was observed. A reentrant behaviour in resistivity and thermoelectric power occurs at the antiferromagnetic phase transition of HoNi2B2C. The thermal conductivity of MgB2 below 7 K is dominated by the scattering of phonons at grain boundaries. The absence of both, a maximum of thermal conductivity in the superconducting state, and the change of its slope at the superconducting transition temperature points to the validity of the two-band model that also describes the temperature dependence of specific heat. Measurements of thermoelectric power confirm the different normal-state character of the charge carriers of the investigated superconductors. Diffusion thermopower and phonon drag describe the measured data of all investigated compounds ov a wide range of temperature. The thermal expansion of HoNi2B2C below 10 K is dominated by the magnetic contribution. For all investigated substances the Grueneisen parameter features very large values in selected temperature ranges. In the case of MgB2, its temperature dependence is evidently connected with the properties of the relevant phonon mode. For the borocarbides, the electrical resistance depends very weakly on the crystallographic direction, but in contrast the thermal conductivity does in a quite strong manner. Despite of the antiferromagnetic phase transition in the case of HoNi2B2C, thermoelectric power and thermal expansion show minor anisotropy. / In der vorliegenden Arbeit werden Ergebnisse von Untersuchungen an polykristallinem MgB2 sowie an YNi2B2C- und HoNi2B2C-Einkristallen analysiert. Dafür erfolgten Messungen des spezifischen elektrischen Widerstands, der Wärmeleitfähigkeit, der Thermokraft und des linearen thermischen Ausdehnungskoeffizienten. Zudem wurde die spezifische Wärmekapazität polykristalliner Borkarbide bestimmt und aus den erhaltenen Daten die Temperaturabhängigkeit der Lorenz-Zahl und des Grüneisen-Parameters sowie mittels der Ehrenfest-Relation die Druckabhängigkeit der Sprungtemperatur ermittelt. Bei tiefen Temperaturen findet man im normalleitenden Zustand für alle betrachteten Substanzen ein charakteristisches Abweichen des Widerstands vom Bloch-Grüneisen-Gesetz. Bei HoNi2B2C tritt beim antiferromagnetischen Phasenübergang im Widerstand und in der Thermokraft ein reentrant-Verhalten auf. Die thermische Leitfähigkeit von MgB2 wird unterhalb von 7 K durch die Streuung der Phononen an Korngrenzen bestimmt. Das Fehlen eines Maximums in der Wärmeleitfähigkeit im supraleitenden Zustand und einer Anstiegsänderung bei der Sprungtemperatur liefert einen Hinweis auf die Gültigkeit des Zweibandmodells, mit welchem auch der Temperaturverlauf der Wärmekapazität erklärt werden kann. Messungen der Thermokraft bestätigen den unterschiedlichen Charakter der Ladungsträger im normalleitenden Zustand der untersuchten Supraleiter, wobei Elektronendiffusion und Phonon Drag die Messdaten aller betrachteten Verbindungen in weiten Temperaturbereichen beschreiben. Für HoNi2B2C wird die thermische Ausdehnung unterhalb von 10 K durch den Beitrag der magnetischen Ordnung bestimmt. Der Grüneisen-Parameter weist für alle untersuchten Substanzen in Teilbereichen sehr große Beträge auf. Sein Temperaturverlauf hängt bei MgB2 offenbar mit Eigenschaften der maßgeblichen Phononenmode zusammen. Für die Borkarbide ist die Richtungsabhängigkeit des elektrischen Widerstandes sehr schwach, in der Wärmeleitfähigkeit hingegen recht stark ausgeprägt. Abgesehen vom antiferromagnetischen Phasenübergang bei HoNi2B2C weisen Thermokraft und Ausdehnungskoeffizient eine geringe Anisotropie auf.

No description available.

No description available.

Increasing interest in an effciency enhancement of existing energy sources led to an extended research in the field of thermoelectrics. Especially skutterudites with their high power factor (electric conductivity times Seebeck coefficient squared) are suitable thermoelectric materials. However, a further improvement of their thermoelectric properties is necessary. The relatively high thermal conductivity can be decreased by introducing loosely bound guest ions, whereas atom substitution or nanostructuring (as thin films) could yield an increased power factor. The present work proves the feasibility to deposit single phase skutterudite thin films by MBE technique. In this regard CoSby and FeSby film series were deposited with three different methods: i) codeposition at elevated temperatures, ii) codeposition at room temperature followed by post-annealing, and iii) modulated elemental reactant method. The structural and thermoelectric properties of these films were investigated by taking the thermal stability of the film and the substrate properties into account. Compared to the stoichiometric Sb content of skutterudites of 75 at.%, a small excess of Sb is necessary for achieving single phase skutterudite films. It was found, that the deposited single phase CoSb3 films reveal bipolar conduction (and therefore a low Seebeck coefficient), whereas FeSb3 films show p-type conduction and very promising power factors at room temperature. The need of substrates with a low thermal conductivity and a suitable thermal expansion coefficient is also demonstrated. A high thermal conductivity influences the measurements of the Seebeck coefficient and the obtained values will be underestimated by thermal shortening of the film by the substrate. If the thermal expansion coefficient of film and substrate differ strongly from each other, crack formation at the film surface was observed. Furthermore, the realization of controlled doping by substitution as well as the incorporation of guest ions was successfully shown. Hence, this work is a good starting point for designing skutterudite based thin film structures. Two successful examples for such structures are given: i) a thickness series, where a strong decrease of the resistivity was observed for films with a thickness lower than 10nm, and ii) a FexCo1-xSb3 gradient film, for which the gradient was maintained even at an annealing temperature of 400°C.

A construção civil é o maior consumidor de recursos naturais do planeta, apropriando-se atualmente de mais da metade da massa total dos materiais extraídos. Neste contexto, o desenvolvimento de sistemas construtivos que proporcionem uma redução do consumo de materiais, conhecida como o princípio da desmaterialização dos edifícios, pode ser uma estratégia para a redução do impacto que a construção civil exerce sobre o ambiente, e um passo em direção a uma economia mais sustentável. A utilização de placas cimentícias para a produção de vedações vem crescendo em várias partes do mundo, seja para a produção de vedações verticais externas, seja como revestimento não aderido sobre vedos existentes, destinados tanto a melhoria estética quanto o desempenho destas fachadas. Uma vedação com placas cimentícias possui em torno de 25% da massa de uma alvenaria tradicional constituída por blocos de concreto para a execução de uma mesma área de vedação vertical, o que pode contribuir ainda para uma redução dos materiais empregados nas estruturas e fundações de um edifício. Apesar da utilização destas placas cimentícias estar coerente com a estratégia da desmaterialização, algumas experiências de vedações executadas com estes componentes manifestaram problemas de manutenção de suas características ao longo do tempo, apresentando fissuras geralmente nas juntas entre placas. Verificando-se as propriedades dos materiais que constituem esta placa cimentícia, principalmente a variação dimensional em relação à temperatura e umidade, constatou-se uma incompatibilidade entre a amplitude das variações dimensionais resultantes e os sistemas de fixação e juntas empregados para a sustentação das mesmas. A avaliação experimental de choque térmico comprovou a influência destas variações para a deterioração das juntas entre as placas. Com base nesta constatação, e em análises dos processos de fixação de placas cimentícias adotados por fornecedores em diversas partes do mundo, foi desenvolvido neste trabalho um novo sistema de fixação para placas cimentícias e de juntas entre estas com capacidade de atender a esta variação dimensional. Realizaram-se protótipos destes componentes os quais foram submetidos a uma avaliação experimental de choque térmico, resultando em nenhuma alteração visível nas juntas e nas superfícies destas placas. Como resultado concluiu-se que a criação de mecanismos que possibilitem acomodação às variações dimensionais, tanto nos dispositivos de fixação destas à estrutura, quanto nos acabamentos das juntas, podem contribuir significativamente para a durabilidade do sistema de vedações constituída por placas cimentícias. / The construction industry is the largest consumer of natural resources in the planet, currently appropriating more than half of mass of the total material extracted. In this context, the development of building systems that provide their dematerialization can be considered as a strategy to reduce the environmental construction impact, and a step toward a more sustainable economy. The use of fiber cement boards for the building production is growing in many parts of the world, to produce external vertical building enclosure or building envelopes, to improving the aesthetics and performance of these facades. A fiber cement board walls weigh around 25% of the traditional masonry mass made of concrete blocks for the same area of vertical building enclosure which can further contribute to a reduction of the materials used in building structures and foundations. Although the use of fiber cement boards complies with the dematerialization strategy, some experiments carried out with these cladding showed maintenance problems over time, usually cracks in the joints between panels. Checking the properties of materials constituting fiber cement boards, especially the dimensional variation due to changing temperature and humidity, there was an incompatibility between these dimensional variations amplitude and fixing systems and joints used to support them. The thermal shock experimental evaluation proved the influence of these variations on joints deterioration. Based on this observation, and on analyzes of the fiber cement suppliers recommendations over the world, a new system for fixing fiber cement board and joints between them was developed in this work with capacity to adapt to this dimensional variation. Prototypes of these components were made and submitted the thermal shock evaluation, resulting in no visible changes in the joints and on the surfaces of these panels. As a result, it was concluded that the creation of mechanisms that allow accommodating the dimensional variations, both in fixing these panels to the structure, and in the joints finishing can significantly contribute to the vertical building enclosure system durability.

In the present study the results of investigations on polycrystalline MgB2 and on single crystals of YNi2B2C and HoNi2B2C are presented. In particular, measurementes of specific electrical resistance, thermal conductivity, thermoelectric power, and of the linear thermal expansion coefficient were performed. Moreover, the specific heat of polycristalline borocarbide samples was evaluated. From the measured data, the temperature dependencies of the Lorenz number and of the Grueneisen parameter can be determined, also the pressure dependence of the superconducting transition temperature using the Ehrenfest relation. At low temperatures a characteristic deviation of the resistivity from the Bloch-Grueneisen law in the normal state for all investigated substances was observed. A reentrant behaviour in resistivity and thermoelectric power occurs at the antiferromagnetic phase transition of HoNi2B2C. The thermal conductivity of MgB2 below 7 K is dominated by the scattering of phonons at grain boundaries. The absence of both, a maximum of thermal conductivity in the superconducting state, and the change of its slope at the superconducting transition temperature points to the validity of the two-band model that also describes the temperature dependence of specific heat. Measurements of thermoelectric power confirm the different normal-state character of the charge carriers of the investigated superconductors. Diffusion thermopower and phonon drag describe the measured data of all investigated compounds ov a wide range of temperature. The thermal expansion of HoNi2B2C below 10 K is dominated by the magnetic contribution. For all investigated substances the Grueneisen parameter features very large values in selected temperature ranges. In the case of MgB2, its temperature dependence is evidently connected with the properties of the relevant phonon mode. For the borocarbides, the electrical resistance depends very weakly on the crystallographic direction, but in contrast the thermal conductivity does in a quite strong manner. Despite of the antiferromagnetic phase transition in the case of HoNi2B2C, thermoelectric power and thermal expansion show minor anisotropy. / In der vorliegenden Arbeit werden Ergebnisse von Untersuchungen an polykristallinem MgB2 sowie an YNi2B2C- und HoNi2B2C-Einkristallen analysiert. Dafür erfolgten Messungen des spezifischen elektrischen Widerstands, der Wärmeleitfähigkeit, der Thermokraft und des linearen thermischen Ausdehnungskoeffizienten. Zudem wurde die spezifische Wärmekapazität polykristalliner Borkarbide bestimmt und aus den erhaltenen Daten die Temperaturabhängigkeit der Lorenz-Zahl und des Grüneisen-Parameters sowie mittels der Ehrenfest-Relation die Druckabhängigkeit der Sprungtemperatur ermittelt. Bei tiefen Temperaturen findet man im normalleitenden Zustand für alle betrachteten Substanzen ein charakteristisches Abweichen des Widerstands vom Bloch-Grüneisen-Gesetz. Bei HoNi2B2C tritt beim antiferromagnetischen Phasenübergang im Widerstand und in der Thermokraft ein reentrant-Verhalten auf. Die thermische Leitfähigkeit von MgB2 wird unterhalb von 7 K durch die Streuung der Phononen an Korngrenzen bestimmt. Das Fehlen eines Maximums in der Wärmeleitfähigkeit im supraleitenden Zustand und einer Anstiegsänderung bei der Sprungtemperatur liefert einen Hinweis auf die Gültigkeit des Zweibandmodells, mit welchem auch der Temperaturverlauf der Wärmekapazität erklärt werden kann. Messungen der Thermokraft bestätigen den unterschiedlichen Charakter der Ladungsträger im normalleitenden Zustand der untersuchten Supraleiter, wobei Elektronendiffusion und Phonon Drag die Messdaten aller betrachteten Verbindungen in weiten Temperaturbereichen beschreiben. Für HoNi2B2C wird die thermische Ausdehnung unterhalb von 10 K durch den Beitrag der magnetischen Ordnung bestimmt. Der Grüneisen-Parameter weist für alle untersuchten Substanzen in Teilbereichen sehr große Beträge auf. Sein Temperaturverlauf hängt bei MgB2 offenbar mit Eigenschaften der maßgeblichen Phononenmode zusammen. Für die Borkarbide ist die Richtungsabhängigkeit des elektrischen Widerstandes sehr schwach, in der Wärmeleitfähigkeit hingegen recht stark ausgeprägt. Abgesehen vom antiferromagnetischen Phasenübergang bei HoNi2B2C weisen Thermokraft und Ausdehnungskoeffizient eine geringe Anisotropie auf.

In Gasturbinenbrennern kommen Nickelbasiswerkstoffe für thermisch hoch belastete Komponenten standardmäßig zum Einsatz. Die Bauteile liegen strömungstechnisch vor der stattfindenden Verbrennung, wodurch es zu einer stark einseitigen thermischen Belastung kommt. Ein wirtschaftlich effizienter Einsatz von Nickelbasiswerkstoffen kann daher in Kombination mit kostengünstigen warmfesten Stählen für die weniger stark thermisch belasteten Bauteilbereiche erreicht werden. Ziel der vorliegenden Arbeit ist die Prozessentwicklung zum Hochtemperaturlöten von im Brennerbau häufig verwendeten Nickelbasislegierungen und dem niedriglegierten warmfesten Stahl 16Mo3 (1.5415). Im Entwicklungsprozess wurden die Mikrostruktur der Verbunde charakterisiert, die Auswirkungen thermischer Ausdehnungsunterschiede evaluiert und die erreichbare Festigkeit erfasst. An einem Demonstrator wurden die Erkenntnisse im Rahmen der industriellen Fertigung getestet.:1 Einführung 1.1 Einleitung und Motivation 1.2 Stand von Wissenschaft und Technik 1.3 Schlussfolgerungen und Zielsetzung 2 Technologische Grundlagen 2.1 Der Hochtemperaturlötprozess 2.2 Thermische Ausdehnung 2.3 Diffusion 2.4 Metallurgische Prozesse 3 Experimentelle Durchführung 3.1 Grund- und Lotwerkstoffe 3.2 Lötprozesse und Probengeometrien 3.3 Mikrostrukturelle, thermische und mechanische Charakterisierung 4 Ergebnisse und Diskussion 4.1 Mikrostrukturcharakterisierung 4.1.1 Grundwerkstoffe 4.1.2 Lötsystem 16Mo3 – INCONEL 625 4.1.3 Lötsystem 16Mo3 – Nimonic 75 4.1.4 Lötsystem 16Mo3 – Hastelloy X 4.1.5 Lötsystem 16Mo3 – INCONEL 718 4.1.6 Normalisierungsgefüge von 16Mo3 4.1.7 Zusammenfassung der Mikrostrukturcharakterisierung 4.2 Thermische Ausdehnung 4.2.1 Maßänderung 4.2.2 Eigenspannungen 4.3 Mechanische Eigenschaften 4.3.1 Zugversuch 4.3.2 Zugscherversuch 4.3.3 Ermittlung der kritischen Überlapplänge 4.4 Demonstrator 5 Zusammenfassung und Ausblick / Nickel-base alloys for thermally high loaded components are widely used for gas turbine burner parts. By means of flow direction burner parts are located prior to the combustion. They are therefore one-sided thermally loaded. An economical efficient use of nickel based alloys can be achieved in combination with low alloyed steels for thermally less loaded components. The aim of this work is the development of brazing processes for GT-burner manufacturing related nickel based alloys and the low alloyed steel 16Mo3 (1.5415) using nickel based filler materials. The development includes a microstructural characterization of the brazed compounds, the evaluation of thermal expansion behavior and the maximum strength. A final test examines the feasibility by means of industrial manufacturing.:1 Einführung 1.1 Einleitung und Motivation 1.2 Stand von Wissenschaft und Technik 1.3 Schlussfolgerungen und Zielsetzung 2 Technologische Grundlagen 2.1 Der Hochtemperaturlötprozess 2.2 Thermische Ausdehnung 2.3 Diffusion 2.4 Metallurgische Prozesse 3 Experimentelle Durchführung 3.1 Grund- und Lotwerkstoffe 3.2 Lötprozesse und Probengeometrien 3.3 Mikrostrukturelle, thermische und mechanische Charakterisierung 4 Ergebnisse und Diskussion 4.1 Mikrostrukturcharakterisierung 4.1.1 Grundwerkstoffe 4.1.2 Lötsystem 16Mo3 – INCONEL 625 4.1.3 Lötsystem 16Mo3 – Nimonic 75 4.1.4 Lötsystem 16Mo3 – Hastelloy X 4.1.5 Lötsystem 16Mo3 – INCONEL 718 4.1.6 Normalisierungsgefüge von 16Mo3 4.1.7 Zusammenfassung der Mikrostrukturcharakterisierung 4.2 Thermische Ausdehnung 4.2.1 Maßänderung 4.2.2 Eigenspannungen 4.3 Mechanische Eigenschaften 4.3.1 Zugversuch 4.3.2 Zugscherversuch 4.3.3 Ermittlung der kritischen Überlapplänge 4.4 Demonstrator 5 Zusammenfassung und Ausblick