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Process-Dependent Microstructure And Severe Plastic Deformation In Sicp?? Reinforced Aluminum Metal Matrix Composites, Catalina Uribe-Restrepo
Process-Dependent Microstructure And Severe Plastic Deformation In Sicp?? Reinforced Aluminum Metal Matrix Composites, Catalina Uribe-Restrepo
Electronic Theses and Dissertations
Discontinuously reinforced MMCs with optimized microstructure are sought after for exceptional high strain rate behavior. The microstructure evolution of a stir-cast A359 aluminum composite reinforced with 30 vol.% SiCp after isothermal anneal, successive hot-rolling, and high strain rate deformation has been investigated. Quantitative microstructural analysis was carried out for the as-cast, annealed (470°C, 538°C and 570°C) and successively hot rolled specimens (64, 75, 88, and 96% rolling reductions). Selected composites were also examined after high strain rate deformation. X-ray diffraction, optical microscopy, scanning electron microscopy and transmission electron microscopy were employed for microstructural characterization. The strength and ductility of the …
Fatigue Lifetime Approximation Based On Quantitative Microstructural Analysis For Air Plasma Sprayed Thermal Barrier Coatings, Carmen Bargraser
Fatigue Lifetime Approximation Based On Quantitative Microstructural Analysis For Air Plasma Sprayed Thermal Barrier Coatings, Carmen Bargraser
Electronic Theses and Dissertations
The durability of thermal barrier coatings (TBCs) affects the life of the hot section engine components on which they are applied. Fatigue is the general failure mechanism for such components and is responsible for most unexpected failures; therefore it is desirable to develop lifetime approximation models to ensure reliability and durability. In this study, we first examined the microstructural degradation of air plasma sprayed ZrO2-8wt.%Y2O3 TBCs with a low-pressure plasma sprayed CoNiCrAlY bond coat on an IN 738LC superalloy substrate. The durability of TBCs were assessed through furnace thermal cyclic tests carried out in air at 1100°C with a 1-, …