Conference Papers

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    Hot corrosion studies on as-received and HVOF sprayed Al2O 3+CoCrAlTaY on Ti-31 alloy in salt environment
    (Elsevier Ltd, 2013) Jegadeeswaran, N.; Ramesh, M.R.; Bhat, K.U.
    The present investigation is on the High Velocity Oxy-Fuel coating of Ti-31 alloy using fused, blended powder, Al2O3+CoCrAlTaY. Hot corrosion experiments were done on the coated and uncoated Ti-31 under a salt environment of 50% Na2SO4 and 50%V2O 5 at 800°C. Thermogravimetric cycles of 1 hour heating and 20 minute cooling was followed for hot corrosion study. After each cycle weight measurement was carried out. After hot corrosion, the samples were characterized using XRD and SEM/EDS. It was observed that the coated sample is more resistant to hot corrosion than uncoated sample. XRD and SEM analysis indicated that the surface is rich in oxides. Gravimetric analysis indicated that the sample weight gain was following a parabolic relationship with time. A damage mechanism is discussed for the hot corrosion damage of the samples. Presence of high level of chromium in HVOF sprayed coating imparts improved hot corrosion resistance at 800°C, in a molten salt environment of Na2SO4 + V 2O5. © 2013 The Authors. Published by Elsevier Ltd.
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    Hot corrosion stability of double perovskite and pyrochlore in suphate solution of vanadates or chlorides at 900 °C
    (Trans Tech Publications Ltd ttp@transtec.ch, 2015) Baskaran, T.; Sreedhar, G.; Arya, S.B.
    Double perovskites, pyrochlores are having matching thermal expansion co-efficient with bond coat and may act as candidate materials for an intermediate layer between bond coat and top coat in Thermal Barrier Coatings. Hot corrosion stability of double perovskites and pyrochlores is also important for enhanced thermal cycle life. Based on these issues, systematic studies were conducted to find the hot corrosion stability of double perovskites and pyrochlores. The results revealed that, double perovskites and pyrochlores were undergone destabilization in the Na2SO4+50 wt.% V2O5 and Na2SO4+10 wt.% NaCl environments at 900 °C. The implications of these findings addresses the key issues related hot corrosion mechanisms and give a pathway to developing newer materials. This study clearly indicates the destabilization of both double perovskites and pyrochlores in vanadium and chloride environments at 900 °C. © (2015) Trans Tech Publications, Switzerland.