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6851 |
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Nano indentation characterizations of PS-PVD GZO and GYZO coatings |
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ChunMing Deng* / Guangdong Institute of New Materials, P.R. China K. Zhou / Guangdong Institute of New Materials, M. Liu/ Guangdong Institute of New Materials, J. Huang/ Guangdong Institute of New Materials, Z. Q. Deng/ Guangdong Institute of New Materials, |
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Ultra-high temperature TBCs have been paid much attention for the increasing inlet temperature of gas tubine, especially for aero-engine applications. Some oxides have been reported as ceramic thermal barrier coating materials, including Lanthanum compounds, Zirconium compound silicates and rare earth oxides, etc. Of these, Gadolinium zirconate oxides are promising ultra-high temperature ceramic thermal barrier materials for the low thermal conductivity and high temperature stability, but the low fracture toughness of the materials has ill-effects on the performance of coatings. Nano-indentation is a powerful material characterizations especially for thin film and coatings, which can provide a fruitful of information for the coating materials, like load displacement curve, modulus of elasticity, hardness, fracture toughness, strain hardening effect, viscoelastic or creep behavior. In this paper, Gd2Zr2O7 (GZO) and Yb modified Gd2Zr2O7 (GYZO) were prepared by means of PS-PVD (Plasma Spray- Physical Vapor Deposition) technology with NiCrAlY coating as bond coat and YSZ coating as bottom ceramic layer on the substrate of N5 Nickel-based single crystal high temperature alloy. The fundamental properties including load displacement curve, modulus of elasticity, hardness, and fracture toughness for both PS-PVD coatings were characterized via nano-indentation. The study helps to understand the mechanical properties of PS-PVD GZO and GYZO coatings. Keywords: Ultra-high temperature TBCs, GZO and GYZO coatings, PS-PVD, nano-indentation |