Thermal Stability of Novel Multilayer Lanthanum Zirconate Based Thermal Barrier Coatings [chapter]

Xingye Guo, Zhe Lu, Yeon-Gil Jung, Li Li, James Knapp, Jing Zhang
2016 Advances in Materials Science for Environmental and Energy Technologies V: Ceramic Transactions  
La2Zr2O7 is one of the proposed next generation thermal barrier coating materials due to its low thermal conductivity and superior high temperature stability. In this work, La2Zr2O7 and conventional 8 wt% yttria stabilized zirconia (8YSZ) coatings were deposited using plasma spray technique. Both single-layer La2Zr2O7 and double-layer 8YSZ/La2Zr2O7 coating architectures were designed in the matrix for evaluation. Heat treatment, thermal cycling, and thermal shock tests were conducted on the
more » ... les to evaluate their thermal stability. All the La2Zr2O7 coats were delaminated in the furnace cycle test in less than 20 cycles. This is because residual thermal stresses accumulated during thermal cycling. In the heat treatment and the jet engine thermal shock (JETS) tests, the SCL La2Zr2O7 and DCL dense 8YSZ/La2Zr2O7 coatings were fully delaminated. In contrast, the DCL porous 8YSZ/La2Zr2O7 coating sample only partially delaminated on the edge. This is because of the porous 8YSZ layer provides strain compliance. The findings will help to propose efficient thermal barrier coating systems.
doi:10.1002/9781119323624.ch19 fatcat:x5eu3ywdszdqdox5fgn47jivqy