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3662 |
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Wednesday, May 21, 2014, Hall H1 & H2 12:10 PM Aviation Industry 1 |
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Elastic and anelastic behavior of TBCs sprayed at high deposition rates |
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Alfredo Valarezo* / Universidad San Francisco de Quito,
Department of Mechanical Engineering.
& Stony Brook University, Center for Thermal Spray Research, Ecuador Gopal Diwedi / Stony Brook University, USA Sanjay Sampath/ Stony Brook University, USA Radek Musalek/ Institute of Plasma Physics, Czech Republic Jiri Matejicek/ Institute of Plasma Physics, Czech Republic |
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Coatings sprayed at high deposition rates often result in stiff, dense, and highly stressed coatings. The high deposition temperature at which the coatings are formed is responsible for this response. In this paper, TBCs were sprayed at high deposition rates increasing the tensile quenching stresses beyond the threshold of crack opening during spraying. Dense structures were observed within a pass, in presence of micro and macro defects specifically horizontal cracks within interpasses and vertical segmentation cracks. Mechanical properties, mainly, the elastic and anelastic behavior of TBCs were significantly affected by the strain accommodation and friction occurring within intersplats and interpass interfaces. The strain tolerance obtained in as sprayed conditions decreased as the microstructure and defects sintered during high temperature heat cycles. The non-linear degree and elastic modulus of the various coatings were increased to a maximum value. |