TY - GEN
T1 - Phase transformation stress field due to hot corrosion in the top coat of TBC
AU - Abubakar, Abba Abdulhamid
AU - Akhtar, Syed Sohail
AU - Arif, Abul Fazal M.
PY - 2013
Y1 - 2013
N2 - Due to the use of low quality fuels in Saudi Arabia, hot corrosion occurs at the top coat of Thermal Barrier Coatings (TBCs) as a result of the formation of a molten salt, V2O5, which penetrates it through either diffusion mechanism or the open porosities in the YSZ. The interaction between this molten salt and the Zirconia stablizer is a dissolution-precipitation type reaction which occurs throughout the Planar Reaction Zone (PRZ) and the Melt-Infiltrated Reaction Zone (MIRZ) leaching a new phase, YVO4, and also causing tetragonal to monoclinic phase transformation of Zirconia. Swelling due to transformation-mismatch plasticity causes the development of localized stresses in the topcoat which subsequently contributes to the premature failure of the coating. In the current work, a ID-Phase field model was developed that could estimate the kinetics and micro-structural evolution during the isothermal (diffusional) tetragonal-to-monoclinic phase transformation at 900°C in the top coat. The result obtained from the Phase Field Model was sequentially coupled with Finite Element Method, and the resulting stress field in the top coat was predicted.
AB - Due to the use of low quality fuels in Saudi Arabia, hot corrosion occurs at the top coat of Thermal Barrier Coatings (TBCs) as a result of the formation of a molten salt, V2O5, which penetrates it through either diffusion mechanism or the open porosities in the YSZ. The interaction between this molten salt and the Zirconia stablizer is a dissolution-precipitation type reaction which occurs throughout the Planar Reaction Zone (PRZ) and the Melt-Infiltrated Reaction Zone (MIRZ) leaching a new phase, YVO4, and also causing tetragonal to monoclinic phase transformation of Zirconia. Swelling due to transformation-mismatch plasticity causes the development of localized stresses in the topcoat which subsequently contributes to the premature failure of the coating. In the current work, a ID-Phase field model was developed that could estimate the kinetics and micro-structural evolution during the isothermal (diffusional) tetragonal-to-monoclinic phase transformation at 900°C in the top coat. The result obtained from the Phase Field Model was sequentially coupled with Finite Element Method, and the resulting stress field in the top coat was predicted.
KW - Finite element analysis(FEA)
KW - Monoclinic phase(m-phase)
KW - Phase field model(PFM)
KW - Tetragonal phase(t-phase)
KW - Thermal Barrier Coatings (TBC)
KW - Yttria Stabilized Zirconia(YSZ)
UR - https://www.scopus.com/pages/publications/84903475168
U2 - 10.1115/IMECE2013-63138
DO - 10.1115/IMECE2013-63138
M3 - Conference contribution
AN - SCOPUS:84903475168
SN - 9780791856178
T3 - ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE)
BT - Advances in Aerodynamics
PB - American Society of Mechanical Engineers (ASME)
ER -