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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 14 of 14 for “"refractory metals"”.
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JOINING OF ULTRA-HIGH TEMPERATURE CERAMICS TO THE SAME AND REFRACTORY METALS VIA FUSION WELDING
… temperature ceramics to either themselves or refractory metals/alloys via fusion welding and the mechanical strength of produced joints. The ceramics studied consisted of compositions within a diboride-carbide-carbide ternary system while metals studied consisted of molybdenum and a molybdenum …
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Electrodeposition of Nb, Ta, Zr and Cu from Ionic Liquid for Nanocomposites Preparation
… applications. Composite materials based on metals with different characteristics give rise to new materials with unique properties. Among the others, nanostructured composites constituted by immiscible metals can present interfaces able to control defects produced by high doses of radiation, …
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Dependence of rare-gas adsorbate dipole moment on substrate work function
… behaviors of rare gas adsorbed on various metals has been a puzzle for more than two decades. On refractory metals, the deduction of the metal work functions is unexpectedly large, while on simple metals, the effect is nearly undetectably small. The ""switching"" theory proposed by Flynn …
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Evaluation of electrothermal vapourization as a method of sample introduction for the ICP-MS and determination of trace levels of titanium, gallium and indium in the central Pacific gyre
The analysis of trace metals in the ocean is a relatively new field of study. Since the elements of interest often exist at picomolar levels, this work demands analytical methods with ultra low detection limits. The inductively coupled plasma mass spectrometer (ICP-MS), with its improved detection …
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Electronica Devices and Interface Strategies for Nanotechnology
Evaporation of ultra-thin layers of refractory metals onto glass substrates represents a relatively simple method of fabricating discontinuous metal films. The utility of these films in nanotechnology is based on the ability to control their morphology. In this thesis, control of discontinuous …
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Ultrasonic Pyrometer for Industrial Applications
… gaseous environments above 1000°C and in liquid metals. It is based on the temperature dependence of the velocity of sound in solid materials. A resonance technique is used to measure the frequency of a sensor and hence the sound velocity. The pyrometer can be described in three parts; the probe …
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Alloy design or three-dimensional printing of hardenable tool materials
… 3DP system. A thermodynamic database for steels, refractory metals and copper-based infiltrants for use with Thermo-Calc was developed with assessments of fifteen binary systems.
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Annealing effects on platinum coating morphology
… Intermetallic compounds based on platinum group metals have almost unique properties. Many of them exhibit outstanding thermodynamic stability in aqueous and elevated temperature applications. Therefore, the platinum group metals base intemetallics are of particular interest as next generation …
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Interaction of plasmas with lithium and tungsten fusion plasma facing components
… replacement in higher heat flux devices. As a refractory metal, tungsten’s large melting point and thermal conductivity as well as its low sputtering yield have led to its selection as the material of choice of the ITER divertor. Experiments have reinforced this choice demonstrating tungsten’s …
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The role of alloying elements on the microstructure and thermal stability of Refractory Metal High Entropy Superalloys
… alloys are being investigated, including refractory metal high entropy superalloys (RSAs), based on the AlMoNbTaTiVZr system. These alloys comprise nanoscale order-disordered B2+bcc microstructures, similar to nickel-based superalloys, and have promising high temperature compressive yield …
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Understanding and Optimizing Nanophase Separation Sintering
… difficult to produce, such as parts made from refractory metals. Various sintering methods such as liquid phase sintering and supersolidus liquid phase sintering have been used to enhance densification and reduce the sintering time of the materials. Nanophase separation sintering (NPSS) was …
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Stability of nickel-base superalloys for turbine disc applications
… resistance and increased concentrations of other refractory metals to improve solid solution strengthening. However, these elements compromise the alloyâs long-term microstructural stability by promoting the formation of topologically close-packed (TCP) phases, which are deleterious to alloy …
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Effect of roughness, microstructure, and chemistry on the environmental durability of structural alloys
… stability enhancement by 500 oC, comparable to refractory metals in the same configuration. And also improved both the modulus and hardness of these structures.
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Processing and irradiation-driven evolution of refractory microstructures
… evolution and material performance of refractory metals and ceramics through two lenses: one driven by processing under non-equilibrium conditions, and the other driven by non-equilibrium or extreme environments experienced during service-like conditions (specifically, under …