Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Effect of Biofuel Impurities on the Hot Corrosion of Yttria-Stabilized Zirconia Thermal Barrier Coatings" By Jorge H. Ramirez-Velasco Purdue MSE Ph.D. Preliminary Exam Advisor: Professor Rodney W. Trice ABSTRACT Aircraft propulsion and industrial power generation have highlighted the critical role of gas turbines in modern society. Currently, components for these applications must withstand temperatures of at least 1400°C when operating within the combustor and the high-pressure sections of a gas turbine engine. With superalloys operating at its maximum capacity, ceramic multilayered materials systems known as thermal barrier coatings (TBCs) are employed as thermal and environmental protection. However, the introduction of biofuels into gas turbines applications have come with new challenges. The contaminants found in military and commercial biofuels are known to include oxides of alkali and alkaline earth metals and silicon oxides. Furthermore, while calcium-magnesium-aluminum silicates (CMAS) are typically ingested as particulate in middle-east theaters, the impurity list in biofuels includes the necessary elements to form CMAS without exposure to any specific environment. This is very significant as CMAS is particularly destructive for operating temperatures above its melting temperature (~1250°C), mainly reducing yttria-stabilized zirconia (YSZ) TBCs lifetimes. Thus, identification of the corrosive compounds product of the interaction of biofuel contaminants/thermal barrier coatings and a specific understanding of its adverse effect its mandatory to avoid premature failure of gas turbines. In the proposed work, solutions containing the impurities of interest are prepared and sprayed onto TBCs simulating the deposit of the impurities during combustion. Subsequently, the TBCs are subject to static and dynamic heating up to 1400°C and their microstructures evaluated. Date: Wednesday, February 28, 2018 Time: 12:00 P.M. Place: ARMS 3115 PURDUE MSE [cid:image003.png@01D3AFC0.B611FC50]
