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Full-Text Articles in Engineering
Microstructure And Electrical Performance Of Sputter-Deposited Hafnium Oxide (Hfo2) Thin Films, Brandon Adrian Aguirre
Microstructure And Electrical Performance Of Sputter-Deposited Hafnium Oxide (Hfo2) Thin Films, Brandon Adrian Aguirre
Open Access Theses & Dissertations
Hafnium oxide (HfO2) based dielectrics have been currently considered as the possible replacements for the traditional gate-oxide (SiO2) of the complementary metal-oxide semiconductor (CMOS) devices. The high dielectric constant, wide band gap, and thermal stability in contact with Si make HfO2 a potential material for application in CMOS devices. The performance of HfO2 as a gate oxide material, however, depends on its quality and interface structure with Si. In this work, HfO2 thin films have been deposited by rf sputtering onto Si(100) substrates under varying growth temperatures (Ts). The objective of the work is to understand the growth and microstructure …
Microstructural Characterization Of Overaged Gtd-111 Hp Turbine Buckets, Oscar Quintero
Microstructural Characterization Of Overaged Gtd-111 Hp Turbine Buckets, Oscar Quintero
Open Access Theses & Dissertations
Superalloys are metallic materials that exhibit excellent mechanical strength and creep resistance at high temperatures. They have good surface stability and are corrosion resistant. Superalloys are mostly used in the aerospace industry, gas turbine engines and blades (hot zones of gas turbines), and where extreme heat is encountered. The focus of this research was on the GTD-111 Ni-base superalloy, which is a General Electric (GE) proprietary superalloy mostly used in gas turbine blades with the form of high pressure or first stage buckets. This alloys features better mechanical properties, creep resistance, and a higher stress rupture temperature than the commonly …
Microstructural Characterization And Heat Treatment Of A-286 Turbine Buckets, Christopher Michael Bradley
Microstructural Characterization And Heat Treatment Of A-286 Turbine Buckets, Christopher Michael Bradley
Open Access Theses & Dissertations
A-286 is an iron-based superalloy used extensively in land-based gas turbines for 2nd stage (low pressure) buckets and 1st and 2nd stage wheels. Although A-286 may appear to some as just another austenitic stainless steel, its elevated temperature properties are attributed to ' precipitate structures, effective distributions of alloy carbides in the forms of M23C6, M6C and MC, and solid solution strengthening. Unfortunately over the course of these components service lives microstructural degradation develops in the form of η-phase formation. The presence of η-phase, especially in large quantities, can have a negative effect on stress rupture properties. Resistance to creep …