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Showing 1 to 15 of 15 for “"Microstructural stability"”.
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Phase and Microstructural Stability in Immiscible Binary Alloys Under Irradiation
In the experimental part, we investigate the microstructures resulting under ion-beam mixing in Ag-Cu multilayers. We find that, regardless of the irradiation temperature, extensive grain growth takes place. In the regime when thermal decomposition is in dynamic balance with irradiation mixing, …
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Thermodynamic stability and implications of anisotropic boundary particles
… ser- ration through torques, has implications in microstructural stability and illustrates avenues for future research.
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Novel metal oxide nanocomposites for oxygen storage, sulfur dioxide adsorption and hydrogen sulfide absorption
… secondary metal oxide doping to improve thermal stability and oxygen accessibility. 20 at% substitution of Pr, Sc and Zr in CeO2 successfully promoted microstructural stability, with Ceo.8Zro0.202- retaining grain size of 30 nm even after calcination at 10000C. At high doping levels, Zr improved …
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Nanoscale self-organization in irradiated ternary alloys
Microstructural stability of nanostructured alloys under harsh environments such as high temperatures and high dose irradiation is a primary concern in the deployment of those materials for engineering applications. This thesis work explores several pathways to stabilize nanostructures in Cu-based …
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Untersuchungen der Strukturstabilität von Ni-(Fe)-Basislegierungen für Rotorwellen in Dampfturbinen mit Arbeitstemperaturen über 700 C
… are suitable for their fabrication, structure stability and thermo-mechanical characteristics. With view on creep and creep crack growth resistance as suitable candidates in the context a DFG research project wrought Ni-based superalloy Waspaloy and Ni-Fe-based alloy Inconel 706 were selected, …
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Grain Boundary Solute Segregation in Vanadium
… annealing, indicating better grain boundary stability. The powder metallurgical route used produce these vanadium alloys requires a subsequent sintering step to densify powders into bulk parts for engineering applications, and dilatometry experiments reveal that that the addition of strongly …
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Friction stir welding of commercially available superplastic aluminium
… evaluated for room temperature properties and microstructural stability. The results have then been used to assess the welds and select the most suitable structure for cone testing, which is used to test the welds‘ performance during SPF. Friction stir welds were then recreated and cone tested …
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Stability of nickel-base superalloys for turbine disc applications
… these elements compromise the alloyâs long-term microstructural stability by promoting the formation of topologically close-packed (TCP) phases, which are deleterious to alloy performance. High $\gamma^\prime$ volume fractions, which are needed to provide high-temperature strength, exacerbate the …
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Magnetic Detection of Microstructural Change in Power Plant Steels
… for this application are chosen to confer microstructural stability and creep resistance. Nevertheless, gradual microstructural changes, which eventually degrade the creep properties, occur during the long service life. Conservative design lives are used in power plant, and it is often …
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Novel approaches for the characterisation of spinodal alloys
… have motivated efforts to improve the microstructural stability of spinodal alloys, primarily through trace element additions and thermo‑mechanical processing. For reliable assessment of the evolution and stability of spinodal alloy microstructures, the use of advanced characterisation …
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The role of alloying elements on the microstructure and thermal stability of Refractory Metal High Entropy Superalloys
… fraction of the Al-Zr-rich intermetallic formed. Microstructural stability of RSAs is critical to retain advantageous properties during high temperature service. Throughout this work, homogenised alloys were exposed to long duration thermal exposure at sub-solvus temperatures. In both simplified …
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Use of sol chemistry and fine grained precursors in the production of controlled microstructural polycrystalline continuous oxide fibres
… determine the purity, oxide phase evolution and microstructural stability with temperature and time. During conversion of the sol-gel fibres to the polycrystalline fibre SEM imaging and elemental analysis showed that careful heat treatment was necessary to remove volatile components such as …
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Development of Low-Cost Polycrystalline Nickel-Base Superalloys for Gas Turbine Applications
… high temperature mechanical properties, thermal stability and oxidation resistance. Extensive alloy development has produced a diverse class of alloys suited to a wide range of operating conditions. This work details research performed to develop new low-cost polycrystalline Ni-base superalloys, …
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Enhancing hot tooling to forge high-γ ′ superalloys
… both the alloys displayed good thermal stability upon isothermal ageing at 700 °C. H282 maintained stability in microstructure and strength even above 800 °C, while VDM 780 experienced weakening due to dissolution and coarsening of γ ′ and a simultaneous δ precipitation. Creep testing …
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Processing and irradiation-driven evolution of refractory microstructures
… aims to understand the interplay between microstructural 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 …