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Full-Text Articles in Engineering
In-Situ Synchrotron Studies Of Turbine Blade Thermal Barrier Coatings Under Extreme Environments, Kevin Knipe
In-Situ Synchrotron Studies Of Turbine Blade Thermal Barrier Coatings Under Extreme Environments, Kevin Knipe
Electronic Theses and Dissertations
Thermal Barrier Coatings have been used for decades to impose a thermal gradient between the hot combustion gases and the underlying superalloy substrate in engine turbine blades. Yttria Stabilized Zirconia (YSZ) is an industry standard high temperature ceramic for turbine applications. The protective coating is adhered to the substrate using a nickel based alloy bond coat. Through exposure to high temperature, a Thermally Grown Oxide (TGO) layer develops at the bond coat-YSZ interface. Large residual stresses develop in these layers due to thermal expansion mismatch that occurs during cool down from high temperature spraying and cyclic operating conditions. Despite their …
Nondestructive Analysis Of Advanced Aerospace Materials Via Spectroscopy And Synchrotron Radiation, Albert Manero
Nondestructive Analysis Of Advanced Aerospace Materials Via Spectroscopy And Synchrotron Radiation, Albert Manero
Electronic Theses and Dissertations
Advanced aerospace materials require extensive testing and characterization to anticipate and ensure their integrity under hostile environments. Characterization methods utilizing synchrotron X-Ray diffraction and spectroscopy can decrease the time required to determine an emerging material's readiness for application through intrinsic information on the material response and failure mechanisms. In this study, thermal barrier coating samples applicable to turbine blades of jet engines were studied using Raman and Photoluminescence spectroscopy as well as Synchrotron X-ray diffraction while Kevlar based fiber composites applicable to ballistic resistant armor were studied using Raman spectroscopy to investigate the mechanical state and corresponding damage and failure …
Load Transfer In An Isolated Particle Embedded Within An Epoxy Matrix, Erik Durnberg
Load Transfer In An Isolated Particle Embedded Within An Epoxy Matrix, Erik Durnberg
Electronic Theses and Dissertations
Particulate composites are widely used in many aerospace applications such as protective coatings, adhesives, or structural members of a body and their mechanical properties and behavior have gained increasing significance. The addition of modifiers such as alumina generally leads to improved mechanical properties. This addition also enables the non-invasive study of the load transfer between the particle and the matrix. Understanding the load transfer between the particulate and the matrix material is the first step to understanding the behavior and mechanical properties of the composite as a whole. In this work, samples with an isolated alumina particle embedded in an …
Diffraction Studies Of Deformation In Shape Memory Alloys And Selected Engineering Components, Chandrasen Rathod
Diffraction Studies Of Deformation In Shape Memory Alloys And Selected Engineering Components, Chandrasen Rathod
Electronic Theses and Dissertations
Deformation phenomena in shape memory alloys involve stress-, temperature-induced phase transformations and crystallographic variant conversion or reorientation, equivalent to a twinning operation. In near equiatomic NiTi, Ti rich compositions can exist near room temperature as a monoclinic B19' martensitic phase, which when deformed undergoes twinning resulting in strains as large as 8%. Upon heating, the martensite transforms to a cubic B2 austenitic phase, thereby recovering the strain and exhibiting the shape memory effect. Ni rich compositions on the other hand can exist near room temperature in the austenitic phase and undergo a reversible martensitic transformation on application of stress. Associated …