Thermal barrier coatings (TBCs) are used in gas turbine engines to achieve higher turbine inlet temperatures (TITs), improve turbine operating temperatures, reduce fuel consumption, increase components lives and thus lead to better turbine efficiency. Yttria-stabilized zirconia (YSZ), is an ideal candidate for TBCs as it has good thermal shock resistance, high thermal stability, low density, and low thermal conductivity. Traditionally, there are two main methods of fabricating TBCs: air plasma spray (APS) TBCs and electron beam physical vapor deposition (EBPVD) TBCs. It is the objective of this paper to study the effects of APS TBC microstructures in comparison with EBPVD TBCs deposited on NiCoCrAlYHf bond coated In738 substrate material for applications in advanced gas turbines. The bond coat NiCoCrAlY contains 0.25w% Hf which is expected to improve the reliability of standard (STD) and vertically cracked (VC) APS TBC material. TBC top coatings of 300 μm and 600 μm thickness for both standard and VC APS TBC and 300 μm EBPVD TBC were further investigated to determine the effect of coating thickness of TBC performance. Selected test specimens were evaluated for dry and wet thermal cyclic oxidation performance. Thermal property determination of select samples was achieved using a laser flash system that measures the thermal diffusivity and specific heat capacity from which the thermal conductivity is calculated. Lastly, select YSZ-Al 2 O 3 composite structures were analyzed in addition to APS and EBPVD TBC microstructure, porosity, and thermal conductivity determination using a variety of analytical techniques. A laser flash system was used to measure the thermal diffusivity for all the samples. A POREMASTER 33 system was used to measure the porosity of the APS and EBPVD samples.

This paper will propose a concept of efficiently capturing the power of ocean waves. Many concepts have been pursued for over 100 years, but none have proven to be commercially viable for widespread operation. The waves offer 2 to 3 million megawatts of clean, renewable energy globally with up to 65 megawatts available per mile of coastline in favorable locations; furthermore, 60% of the world’s population lives within 100 miles of a coastline. Developing a cost-competitive system offers the potential to contribute to the world’s growing energy needs while preserving the environment. The proposed concept is designed to overcome the difficulties of competing concepts by preventing system destruction due to severe storms and bio fouling — the degradation of precision components in a corrosive environment. The author has developed a working model that has been deployed in the ocean, constructed of “low tech” building materials that demonstrated continuous turning of a large flywheel, moment of inertia of 250 kg m**2. The patented concept offers a means for rapidly constructing the energy capture mechanism and keeping the critical precision components protected from the ocean environment. Building on this success, a large-scale demonstration is proposed to assess performance of a commercially viable configuration.