Investigation of three steps of hot corrosion process in Y2O3 stabilized ZrO2 coatings including nano zones
来源期刊：JOURNAL OF RARE EARTHS2014年第10期
论文作者：Mohammadreza Daroonparvar Muhamad Azizi Mat Yajid Noordin Mohd Yusof Hamid Reza BakhsheshiRad Esah Hamzah Mohsen Nazoktabar
文章页码：989 - 1002
摘 要：Phase transformation of tetragonal ZrO2 to monoclinic phase and also increment of bond coat oxidation kinetic（TGO thickening） can substantially restrict the life time of thermal barrier coating systems（TBCs）. So, nanostructured and conventional Y2O3 stabilized ZrO2 coatings were evaluated in fused V2O5-Na2SO4 salts during thermal exposure in air. Microstructural characterization showed lower hot corrosion products（monoclinic zirconia, YVO4 crystals） formation and reduction of TGO thickness in thermal barrier coating system consisting of nanostructured Y2O3 stabilized ZrO2（YSZ） top coat. It was found that inhomogeneities, pores and micro-cracks played a principal role in the molten salts infiltration into the YSZ coating during three steps of hot corrosion process. In the nanostructured YSZ coating with tri-model structure, nano zones which surrounded by fully molten parts could fill the aforementioned defects and could act as barrier for the oxygen and corrosive molten salts penetration into the TBC.
Mohammadreza Daroonparvar1，Muhamad Azizi Mat Yajid1，Noordin Mohd Yusof1，Hamid Reza BakhsheshiRad1，Esah Hamzah1，Mohsen Nazoktabar2
1. Department of Materials,Manufacturing and Industrial Engineering,Faculty of Mechanical Engineering,Universiti Teknologi Malaysia2. Department of Mechanical Engineering,Faculty of Engineering,Roudehen Islamic Azad University
摘 要：Phase transformation of tetragonal ZrO2 to monoclinic phase and also increment of bond coat oxidation kinetic（TGO thickening） can substantially restrict the life time of thermal barrier coating systems（TBCs）. So, nanostructured and conventional Y2O3 stabilized ZrO2 coatings were evaluated in fused V2O5-Na2SO4 salts during thermal exposure in air. Microstructural characterization showed lower hot corrosion products（monoclinic zirconia, YVO4 crystals） formation and reduction of TGO thickness in thermal barrier coating system consisting of nanostructured Y2O3 stabilized ZrO2（YSZ） top coat. It was found that inhomogeneities, pores and micro-cracks played a principal role in the molten salts infiltration into the YSZ coating during three steps of hot corrosion process. In the nanostructured YSZ coating with tri-model structure, nano zones which surrounded by fully molten parts could fill the aforementioned defects and could act as barrier for the oxygen and corrosive molten salts penetration into the TBC.
关键词：
