Microstructure and thermal & mechanical properties of La2Zr2O7@YSZ composite ceramic

La₂Zr₂O₇ used as a top coat material has low thermal conductivity and high stability at high temperature, but it also has a low fracture toughness, which limits its application. To improve the fracture toughness of La₂Zr₂O₇, a La₂Zr₂O₇@YSZ core–shell structured composite ceramic was designed and prepared. The morphology of the La₂Zr₂O₇@YSZ composite ceramic was investigated using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The resulting images show that the YSZ is coated on the surface of the La₂Zr₂O₇. The phases were analyzed by X-ray diffraction (XRD), and the XRD patterns show that pyrochlore and fluorite structures coexist in the La₂Zr₂O₇@YSZ composite material without any chemical reaction. Differential scanning calorimetry (DSC) was used to detect the heat change of the composite ceramic during heat treatment. The properties of the La₂Zr₂O₇@YSZ composite ceramic, such as the thermal conductivity, coefficient of thermal expansion (CTE), and mechanical properties were investigated using a laser flash method, high-temperature dilatometer, and nano-hardness tests, respectively. The thermal conductivity of the composite ceramic is in the range of 1.7745–2.3076 W m⁻¹ K⁻¹ in the temperature regime of 200–1000 °C. The maximum CTE of the composite ceramic is 10.3 × 10⁻⁶/°C. Owing to the thin YSZ coating on the La₂Zr₂O₇ surface, the hardness and Young's modulus of the composite ceramic are 8.17 GPa and 168.3 GPa, respectively. The nucleation and propagation of micro-cracks are investigated using a micro-hardness tester. Compared to La₂Zr₂O₇, the micro-cracks in the composite ceramic are shorter and more tortuous. The weak interface between the YSZ and La₂Zr₂O₇ results in the nucleation and tortuous propagation of micro-cracks, which depletes part of the energy and improves the fracture toughness of the composite ceramic. The results reveal that the La₂Zr₂O₇@YSZ composite ceramic has good mechanical and thermophysical properties.     

Thermal cycling performance of La2Ce2O7/50 vol.% YSZ composite thermal barrier coating with CMAS corrosion

La₂Ce₂O₇ (LC) is receiving increasing attention due to its lower thermal conductivity, better phase stability and higher sintering resistance than yttria partially stabilized zirconia (YSZ). However, the low fracture toughness and the sudden drop of CTE at approximately 350?°C greatly limit its application. In this study, the LC/50?vol.% YSZ composite TBC was deposited by supersonic atmospheric plasma spraying (SAPS). Compared to YSZ or double layered LC/YSZ coating, the thermal cycling life of LC/50?vol.% YSZ coating with CMAS attack increased by 93% or 91%. The latter possessed higher fracture toughness (1.48?±?0.26?MPa?m^1/2) than LC (0.72?±?0.15?MPa?m^1/2) and better CMAS corrosion resistance than YSZ owing to the formation of Ca₂(La_xCe_1-x)₈(SiO₄)₆O_6–4x with <001> orientation perpendicular to the coating surface. The sudden CTE decrease of LC was fully suppressed in LC/50?vol.% YSZ coating due to the change of temperature dependent residual stresses induced by YSZ.     

Improved properties of scandia and yttria co-doped zirconia as a potential thermal barrier material for high temperature applications

Due to the limited temperature capability of current YSZ thermal barrier coating (TBC) material, considerable effort has been expended world-wide to research new candidates for TBC applications above 1200?°C. Our study suggested that Sc₂O₃ and Y₂O₃ co-doped ZrO₂ (ScYSZ) had excellent t’ phase stability even after annealed at 1500?°C for 336?h. The thermal expansion coefficient of ScYSZ was comparable to the value of YSZ. The thermal conductivity of fully dense ScYSZ was in the range of 2.13–1.91?W?m^?1?K^?1 (25–1300?°C), approximately 25% lower than that of YSZ. Although the fracture toughness of dense ScYSZ was slightly lower than YSZ, an evident decline in elastic modulus was found. Additionally, thermal cycling lifetime of plasma sprayed ScYSZ coating (914 cycles) at 1300?°C was about 2.6 times longer than its YSZ counterpart. The superior comprehensive properties confirm that ScYSZ is a prospective candidate material for high-temperature TBC application.     

Synthesis and thermophysical properties of RETa3O9 (RE = Ce,Nd, Sm,Eu, Gd,Dy, Er) as promising thermal barrier coatings

Thermal barrier coatings (TBCs) are one of the most important materials in gas turbine to protect the high temperature components. RETa₃O₉ compounds have a defect‐perovskite structure, indicating that they have low thermal conductivity, which is the critical property of TBCs. Herein, dense RETa₃O₉ bulk ceramics were fabricated via solid‐state reaction. The crystal structure was characterized by X‐ray diffraction (XRD) and Raman Spectroscope. Scanning electron microscope (SEM) was used to observe the microstructure. The thermophysical properties of RETa₃O₉ were studied systematically, including specific heat, thermal diffusivity, thermal conductivity, thermal expansion coefficients, and high‐temperature phase stability. The thermal conductivities of RETa₃O₉ are very low (1.33‐2.37 W/m·K, 373‐1073 K), which are much lower than YSZ and La₂Zr₂O₇; and the thermal expansion coefficients range from 4.0 × 10^?6 K^?1 to 10.2×10^?6 K^?1 (1273 K), which is close to La₂Zr₂O₇ and YSZ. According to the differential scanning calorimetry (DSC) curve there is not phase transition at the test temperature. Due to the high melting point and excellent high‐temperature phase stability with these oxides, RETa₃O₉ ceramics were promising candidate materials for TBCs.     

Thermal shock behavior of 8YSZ and double-ceramic-layer La2Zr2O7/8YSZ thermal barrier coatings fabricated by atmospheric plasma spraying

The single-ceramic-layer (SCL) 8YSZ (conventional and nanostructured 8YSZ) and double-ceramic-layer (DCL) La₂Zr₂O₇ (LZ)/8YSZ thermal barrier coatings (TBCs) were fabricated by plasma spraying on nickel-based superalloy substrates with NiCrAlY as the bond coat. The thermal shock behavior of the three as-sprayed TBCs at 1000 °C and 1200 °C was investigated. The results indicate that the thermal cycling lifetime of LZ/8YSZ TBCs is longer than that of SCL 8YSZ TBCs due to the fact that the DCL LZ/8YSZ TBCs further enhance the thermal insulation effect, improve the sintering resistance ability and relieve the thermal mismatch between the ceramic layer and the metallic layer at high temperature. The nanostructured 8YSZ has higher thermal shock resistance ability than that of the conventional 8YSZ TBC which is attributed to the lower tensile stress in plane and higher fracture toughness of the nanostructured 8YSZ layer. The pre-existed cracks in the surface propagate toward the interface vertically under the thermal activation. The nucleation and growth of the horizontal crack along the interface eventually lead to the failure of the coating. The crack propagation modes have been established, and the failure patterns of the three as-sprayed coatings during thermal shock have been discussed in detail.     

Structure evolution,thermal properties and sintering resistance of promising thermal barrier coating material La2(Zr0.75Ce0.25)2O7

Rare-earth doped zirconates are promising candidate materials for high-performance thermal barrier coatings (TBCs). The phase and microstructure stability is an important issue for the materials that must be clarified, which is related to the long-term stable work of TBCs at high temperatures. In this work, La₂(Zr_0.75Ce_0.25)₂O₇ (LCZ) ceramic coatings prepared by atmospheric plasma spraying present a metastable fluorite phase, which can transform into stable pyrochlore under high-temperature annealing. The detailed structure evolution of the ceramic coatings is characterized systematically by SEM, XRD and Raman. The associated thermal properties of LCZ ceramics were also reported. Results show that LCZ ceramic has an ultralow thermal conductivity (0.65 W/m·K, 1200 °C), which is only 1/3 of that of yttria-stabilized zirconia (YSZ). The thermal expansion coefficients of LCZ ceramic increase from 9.68 × 10^-6 K^-1 to 10.7 × 10^-6 K^-1 (300 - 1500 °C), which are relatively larger than those of La₂Zr₂O₇. Besides, Long-term sintering demonstrates that LCZ ceramic coating has preferable sintering resistance at 1500 °C, which is desirable for TBC applications.     

Thermophysical properties and cyclic lifetime of plasma sprayed SrAl12O19 for thermal barrier coating applications

About 6-8 wt% yttria-stabilized zirconia (YSZ) is the industry standard material for thermal barrier coatings (TBC). However, it cannot meet the long-term requirements for advanced engines due to the phase transformation and sintering issues above 1200°C. In this study, we have developed a magnetoplumbite-type SrAl₁₂O₁₉ coating fabricated by atmospheric plasma spray, which shows potential capability to be operated above 1200°C. SrAl₁₂O₁₉ coating exhibits large concentrations of cracks and pores (~26% porosity) after 1000 hours heat treatment at 1300°C, while the total porosity of YSZ coatings progressively decreases from the initial value of ~18% to ~5%. Due to the contribution of porous microstructure, an ultralow thermal conductivity (~1.36 W m⁻¹ K⁻¹) can be maintained for SrAl₁₂O₁₉ coating even after 1000 hours aging at 1300°C, which is far lower than that of the YSZ coating (~1.98 W m⁻¹ K⁻¹). In thermal cyclic fatigue test, the SrAl₁₂O₁₉/YSZ double-ceramic-layer coating undertakes a thermal cycling lifetime of ~512 cycles, which is not only much longer than its single-layer counterpart (~163 cycles), but also superior to that of YSZ coating (~392 cycles). These preliminary results suggest that SrAl₁₂O₁₉ might be a promising alternative TBC material to YSZ for applications above 1200°C.     

Performance of YSZ and Gd2Zr2O7/YSZ double layer thermal barrier coatings in burner rig tests

Double layer thermal barrier coatings (TBCs) consisting of a Gd₂Zr₂O₇ (GZO) top and an ytrria stabilized zirconia (YSZ) interlayer have been tested in a burner rig facility and the results compared to the ones of conventional YSZ single layers. In order to gain insight in the high temperature capability of the alternative TBC material, high surface temperatures of up to 1550 °C have been chosen while keeping the bond coat temperature similar. It turned out that the performance of all systems is largely depending on the microstructure of the coatings especially reduced porosity levels of GZO being detrimental. In addition, it was more difficult in GZO than in YSZ coatings to obtain highly porous and still properly bonded microstructures. Another finding was the reduced lifetime with increasing surface temperatures, the amount of reduction is depending on the investigated system. The reasons for this behavior are analyzed and discussed in detail.     

Intermediate temperature electrical properties in 4 mol% ZnO-doped Zr0.92Y0.08O2-α/NaCl-KCl composite electrolyte

In this paper, 4?mol% ZnO-doped Zr_0.92Y_0.08O_2-α (8YSZ) and its 8YSZ+4ZnO/NaCl-KCl composite electrolyte were synthesized by a solid-state reaction. The X–ray diffraction (XRD) analysis indicates that 8YSZ+4ZnO and inorganic chlorides phases can coexist. The inorganic chlorides decrease the synthesis temperature of 8YSZ+4ZnO. The highest conductivities of 8YSZ+4ZnO and 8YSZ+4ZnO-NK are 7.0?×?10^?3 S?cm^?1 and 7.7?×?10^?2 S?cm^?1 at 700?°C, respectively. The oxygen concentration discharge cell shows that 8YSZ+4ZnO and 8YSZ+4ZnO-NK are good oxide ionic conductors under an oxygen-containing atmosphere. Finally, an H₂/O₂ fuel cell based on the 8YSZ+4ZnO-NK electrolyte reached the maximum power density (P_max) of 315.5?mW?cm^?2 at 700?°C.     

Enhanced doping effects of multielement on anisotropic thermal expansion in ZrO2 with new compositions

Coefficient of thermal expansion (CTE) of a solid material plays a critical role for a variety of high temperature applications such as thermal barrier coating (TBC) systems during the thermal cycling process. Ceramics contain ionic bonds; hence they tend to exhibit lower CTE values than alloys/metals. Developing new ceramic thermal barrier materials using promising dopants and compositions that have higher CTE values than the conventional 6-8 wt% Y₂O₃ stabilized ZrO₂(8YSZ) will contribute to the decrease in thermal expansion mismatch between a typical ceramic 8YSZ (10 ~ 11 × 10⁻⁶°C⁻¹) top coat and a metal alloy based bond coat such as NiCrAlY (14 ~ 17×10⁻⁶°C⁻¹, Padture et al., Science, 2002;296:280–4; Liang et al., J Mater Sci Technol, 2011;27(5):408–14), which is highly desirable. This work reports design, modeling, synthesis, and characterization of promising new compositions based on Dy³⁺, Al³⁺, and Ce⁴⁺-doped YSZ that consist of the tetragonal structure and have an enhanced thermal expansion than 8YSZ. The intrinsic CTE at the atomic level has been investigated via molecular dynamics (MD) simulation. The atomic scale analysis provides new insights into the enhanced doping effects of multiple trivalent and tetravalent cations on the lattice structure, lattice energy, and thermal expansion in ZrO₂. The calculated lattice energy becomes smaller with the incorporation of Dy³⁺, Al³⁺, and Ce⁴⁺ions, which corresponds strongly to the increase in CTE. The crystalline size is reduced due to the incorporation of the Al³⁺ and Ce⁴⁺, whereas the sintering resistance is enhanced ascribed to the addition of Dy³⁺ and Al³⁺. Doping Dy³⁺, Al³⁺, and Ce⁴⁺ cations to YSZ increased the CTE value of YSZ and for Dy_0.03Y_0.075Zr_0.895O_1.948, the CTE is 12.494 × 10⁻⁶°C⁻¹ at 900°C, which has an 11% increase, as compared with that of 8YSZ.     

Thermal shock resistance and mechanical properties of La2Ce2O7 thermal barrier coatings with segmented structure

La₂Ce₂O₇ (LCO) is a promising candidate material for thermal barrier coatings (TBCs) application because of its higher temperature capability and better thermal insulation property relative to yttria stabilized zirconia (YSZ). In this work, La₂Ce₂O₇ TBC with segmentation crack structure was produced by atmospheric plasma spray (APS). The mechanical properties of the sprayed coatings at room temperature including microhardness, Young's modulus, fracture toughness and tensile strength were evaluated. The Young's modulus and microhardness of the segmented coating were measured to be about 25 and 5 GPa, relatively higher than those of the non-segmented coating, respectively. The fracture toughness of the LCO coating is in a range of 1.3–1.5 MPa m^1/2, about 40% lower than that of the YSZ coating. The segmented TBC had a lifetime of more than 700 cycles, improving the lifetime by nearly two times as compared to the non-segmented TBC. The failure of the segmented coating occurred by chipping spallation and delamination cracking within the coating.     

Thermal diffusivity characterization of europium zirconate,cerate and hafnate

The following paper presents study on synthesis and thermal diffusivity of europium zirconate, cerate and hafnate as a new types of materials with pyrochlore or fluorite type of lattice, dedicated to replacement of conventional 8YSZ (yttria stabilized zirconia) in TBC (thermal barrier coatings) systems for aircraft gas turbines.All materials were synthesized via solid-state reaction (SSR) preceded preparation of powder mixtures (mechanical milling in ethanol). The feedstock powders were characterized by analysis of crystallite size, particle size distribution and phase composition. On the base of DSC measurements, the parameters of high temperature sintering were selected (1350?°C/2?h/15?MPa). Structural characterization of obtained materials inclusive analysis of morphology, chemical and phase composition of sinters was performed. Thermal diffusivity was measured in temperature range 25÷1400?°C by laser flash analysis (LFA). The obtained materials with pyrochlore and fluorite type of lattice exhibit lower thermal diffusivity compared to that of yttria-stabilized zirconia at high temperatures. In particular, the most promising material in view of insulating properties is Eu₂Ce₂O₇, which exhibit much lower thermal diffusivity than Eu₂Zr₂O₇ and Eu₂Hf₂O₇, especially at temperature higher than 1000?°C. However, in temperature range 25–700?°C, europium hafnate and zirconate exhibit lower thermal diffusivity compared to that of europium cerate and 8YSZ.     

Influence of B-site substituent Ce on thermophysical,oxygen diffusion,and mechanical properties of La2Zr2O7

Pyrochlore-type La₂Zr₂O₇ (LZ) is a promising candidate for high-temperature thermal barrier coatings (TBCs). However, its thermal expansion coefficient and low fracture toughness are not optimal for such application and thus, need to be improved. In this study, we systematically report the effect of CeO₂ addition on phase formation, oxygen-ion diffusion, and thermophysical and mechanical properties of full compositions La₂(Zr₁?_xCe_x)₂O₇ (x = 0, 0.1, 0.3, 0.5, 0.7, 0.9, 1). La₂(Zr₁?_xCe_x)₂O₇ exhibits a pyrochlore structure at x ≤ 0.3, while a fluorite structure is observed outside this range. With the increase in CeO₂ content, thermal expansion coefficient and oxygen-ion diffusivity in La₂(Zr₁?_xCe_x)₂O₇ are increased. Oxygen-ion diffusivity of La₂(Zr₁?_xCe_x)₂O₇ is two orders of magnitude less than that of classical 8YSZ. Among La₂(Zr₁?_xCe_x)₂O₇ compounds, La₂(Zr_0.7Ce_0.3)₂O₇ and La₂(Zr_0.5Ce_0.5)₂O₇ exhibit relatively low oxygen diffusivities. The composition La₂(Zr_0.5Ce_0.5)₂O₇ presents the lowest thermal conductivity due to the strongest phonon scattering and also the highest fracture toughness due to the solid-solution toughening. The highest sintering resistance is achieved by the composition La₂(Zr_0.7Ce_0.3)₂O₇ because of its ordered pyrochlore structure and high atomic mass of Ce. Based on these results, the compositions La₂(Zr_0.5Ce_0.5)₂O₇ and La₂(Zr_0.7Ce_0.3)₂O₇ are alternatives for classical 8YSZ for TBC materials operating at ultrahigh temperatures.     

Characterisation of the microstructure and thermal properties of Nd2Zr2O7 and Nd2Zr2O7/YSZ thermal barrier coatings

The microstructure of following thermal barrier coatings (TBC) was characterised in this paper: monolayer coatings Nd₂Zr₂O₇ and 8YSZ; a double ceramic layered (DCL) coating. Coatings were characterised by thicknesses that did not exceed 300 μm and porosities of approx. 5%. The chemical and phase composition analysis of the DCL layers revealed an external Nd₂Zr₂O₇ ceramic layer approx. 80 μm thick, a transitional zone approx. 120 μm thick and an internal 8YSZ layer 100 μm thick. For the case of the monolayer coating, the Nd₂Zr₂O₇ pyrochlore phase was the only one-phase component. The surface topography of both TBC systems was typical for plasma sprayed coatings, and compressive stress state had a value of approx. 5–10 MPa. Measurements of the thermal parameters, i.e., thermal diffusivity, point to considerably better insulative properties for both new types of layers when compared to the standard 8YSZ layers.     

Y3Ce7Ta2O23.5 and Yb3Ce7Ta2O23.5—Two kinds of novel ceramics for thermal barrier coatings

For the development of ceramic candidates for thermal barrier coatings, two kinds of new ceramics, Y₃Ce₇Ta₂O_23.5 and Yb₃Ce₇Ta₂O_23.5, were synthesized by sintering at 1873?K for 10?h. The obtained samples were composed of a single fluorite-type phase, and their relative densities are greater than 90%. Because of phonon scattering caused by the complex lattice, the large number of oxygen vacancies, and substituted atoms, the thermal conductivity is lower than that of 8YSZ. The coefficients of thermal expansion (CTEs) of these two products are located in the range of 10.22–12.57?×?10^?6/K and 9.62–12.66?×?10^?6/K, respectively, from 323?K to 1473?K, and they also exhibit excellent phase stability up to 1473?K. However, their thermal conductivities and CTEs are lower than those of RE₂Ce₂O₇ (RE?=?La, Nd, or Sm).     

Effect of La2O3 addition and sintering mode on the mechanical properties and microstructural evolution on an 8YSZ ceramic alloy

In this research, the influence of La₂O₃ addition on the microstructure, phase stability and mechanical properties of 8?mol% yttria stabilized zirconia (8YSZ) was studied. 8YSZ with La₂O₃ (9, 12 and 15?wt%) ceramics were fabricated by microwave and conventional sintering at 1400?°C/ 20?min and 1400?°C/ 5?h, respectively. Irrespective of the sintering technique, the relative sintered density was found to decrease with increasing amount of La₂O₃. The grain growth of 8YSZ was enhanced significantly by the addition of La₂O₃. The XRD results demonstrated that addition of La₂O₃ up to 15?wt% did not disrupt the cubic 8YSZ phase regardless of sintering technique; additionally evolution of pyrochlore phase, La₂Zr₂O₇ was observed in all sintered specimens. Vickers hardness of 8YSZ ceramic compacts were also found to decrease with increasing amount of La₂O₃.     

Influence of Gd2O3 addition on thermophysical properties of La2Ce2O7 ceramics for thermal barrier coatings

In order to develop new candidate ceramic materials for thermal barrier coatings (La_1?xGd_x)₂Ce₂O₇ ceramics were prepared by pressureless-sintering at 1600 °C for 10 h in air. The phase structure, micro-morphology and thermophysical properties of (La_1?xGd_x)₂Ce₂O₇ ceramics were investigated, respectively. XRD results revealed that pure (La_1?xGd_x)₂Ce₂O₇ ceramics with defect fluorite structure were synthesized and SEM showed that their microstructures were dense and no other phases existed among the particles. With the increasing temperature, their thermal expansion coefficients increased, while the thermal conductivities decreased. The thermophysical results indicated that thermal expansion coefficients of these ceramics were higher than that of 8YSZ, and their thermal conductivities were much lower than that of 8YSZ. The lower thermal conductivities of these ceramics were mainly attributed to more oxygen vacancies and substitution atoms. These results imply that the (La_1?xGd_x)₂Ce₂O₇ ceramics can be explored as candidate materials for the ceramic layer in TBC system.     

Influence of the intermixed interfacial layers on the thermal cycling behaviour of atmospheric plasma sprayed lanthanum zirconate based coatings

In application as a thermal barrier coating (TBC), yttria stabilised zirconia (YSZ) approaches some limits of performance. To further enhance the efficiency of gas turbines, higher temperature capability and a longer lifetime of the coating are needed for the next generation of TBCs. Pyrochlore oxides of general composition, A₂B₂O₇, where A is a 3⁺ cation (La to Lu) and B is a 4⁺ cation (Zr, Hf, Ti, etc.) have high melting point, fair coefficient of thermal expansion, and low thermal conductivity which make them suitable for applications as high temperature thermal barrier coatings. Among those oxide materials lanthanum zirconate (LZ/La₂Zr₂O₇) offers very attractive properties. This work describes the fabrication, microstructure and high temperature (1280 °C) thermal cycling behaviour of lanthanum zirconate coatings with five different coating architectures, deposited using atmospheric plasma spray process. The coating architecture which had five layers with two intermixed interlayers had much longer life time than other considered architectures. The coatings were characterised using X-ray diffraction, energy dispersive spectrometry, optical and scanning electron microscopy, before and after thermal cycling tests, to study the coating failure mechanisms.     

Low–thermal–conductivity and high–toughness CeO2–Gd2O3 co–stabilized zirconia ceramic for potential thermal barrier coating applications

Yttria partially stabilized zirconia (～4.0?mol% Y₂O₃–ZrO₂, 4YSZ) has been widely employed as thermal barrier coatings (TBCs) to protect the high–temperature components of gas–turbine engines. The phase stability problem existing in the conventional 4YSZ has limited it to application below 1200?°C. Here we report an excellent zirconia system co–doped with 16?mol% CeO₂ and 4?mol% Gd₂O₃ (16Ce–4Gd) presenting nontransformable feature up to 1500?°C, in which no detrimental monoclinic (m) ZrO₂ phase formed on partitioning. It also exhibits a high fracture toughness of ～46?J m^?2 and shows high sintering resistance. Besides, the thermal conductivity and thermal expansion coefficient of 16Ce–4Gd are more competent for TBCs applications as compared to the 4YSZ. The combination of properties suggests that the 16Ce–4Gd system could be of potential use as a thermal barrier coating at 1500?°C.     

The morphology,thermal property,and failure mechanism of GdNdZrO thermal barrier coatings by EB-PVD

Nowadays, the Gd₂Zr₂O₇ thermal barrier coatings (TBCs) have been evaluated as a promising alternative to yttria-stabilized zirconia (YSZ). Thus, this investigation focuses on the thermal property, morphology, and failure mechanism of double ceramic layers (DCLs) GdNdZrO/YSZ advanced TBCs. The GdNdZrO coatings with columnar morphology have been deposited on NiCoCrAlYHf bond coating using an electron beam physical vapor deposition method. Material characterizations mainly include X-ray diffraction, scanning electron microscope, and transmission electron microscopy. The thermal conductivity of GdNdZrO ceramic material is 0.494 W/mK at 1200°C. The thermal shock life of GdNdZrO/YSZ TBCs shows an average shock life of 5235 cycles. The TBC degradation occurs on the crack area within thermally grown oxide layer leading to the interface instability. The interface broken might play an important role in the failure mechanism of TBCs.