Characterization of Ln 4 Al 2 O 9 ( Ln = Y , Sm , Eu , Gd , Tb ) rare-earth aluminates as new high-temperature barriers

A family of cuspidine-type rare-earth aluminates with the general formula Ln4Al2O9 (Ln= Y, Sm, Eu, Gd, Tb) has been prepared as a strategy to improve the thermal barrier coating (TBC) fulfilment. Varying trivalent lanthanides is applied to tailor the properties of oxides as ceramic top coats, for high temperature applications. After different heat treatments, X-ray diffraction (XRD) results concluded that Eu4Al2O9 has the highest structural stability at 1200 and 1300 oC. Moreover, the Y4Al2O9 has a long lifetime at 1000 oC and is stable at 1100 oC. Sm4Al2O9 and Gd4Al2O9 showed higher stability at 1200 oC than that of Tb4Al2O9. However, terbium aluminate exhibited at 300-1000 oC the highest thermal expansion coefficient. For five compositions thermal diffusivity measurements indicated favourable values at 600 oC, which are lower than that of YSZ.

[1]  Vijay Kumar,et al.  Processing and design methodologies for advanced and novel thermal barrier coatings for engineering applications , 2016 .

[2]  Nitin P. Padture,et al.  Advanced structural ceramics in aerospace propulsion. , 2016, Nature materials.

[3]  R. Razavi,et al.  Effect of scandia content on the thermal shock behavior of SYSZ thermal sprayed barrier coatings , 2016 .

[4]  Yulia Fedorova,et al.  Design of functionally graded multilayer thermal barrier coatings for gas turbine application , 2016 .

[5]  F. Ye,et al.  Phase stability and thermal conductivity of RE2O3 (RE=La, Nd, Gd, Yb) and Yb2O3 co-doped Y2O3 stabilized ZrO2 ceramics , 2016 .

[6]  R. Razavi,et al.  Comparison of hot corrosion behavior of nanostructured ScYSZ and YSZ thermal barrier coatings , 2016 .

[7]  Xueying Wang,et al.  A novel thermal barrier coating for high-temperature applications , 2016 .

[8]  Sumana Ghosh.  Thermal Barrier Ceramic Coatings — A Review , 2015 .

[9]  David L. Poerschke,et al.  Effects of cation substitution and temperature on the interaction between thermal barrier oxides and molten CMAS , 2015 .

[10]  Xizhi Fan,et al.  Y4Al2O9 ceramics as a novel thermal barrier coating material for high-temperature applications , 2014 .

[11]  K. Ogawa,et al.  Thermal Shock and Cycling Behavior of Thermal Barrier Coatings (TBCs) Used in Gas Turbines , 2013 .

[12]  Hui Peng,et al.  Influence of partial substitution of Sc2O3 with Gd2O3 on the phase stability and thermal conductivity of Sc2O3-doped ZrO2 , 2013 .

[13]  P. Slater,et al.  Synthesis and characterization of oxyanion (phosphate, sulphate) doped Ba2Sc2−yGayO5 , 2013 .

[14]  F. Ansart,et al.  Sol–gel processing and characterization of (RE-Y)-zirconia powders for thermal barrier coatings , 2011 .

[15]  E. R. Losilla,et al.  Stability and oxide ion conductivity in rare-earth aluminium cuspidines , 2006 .

[16]  F. Tietz,et al.  Zirconates as New Materials for Thermal Barrier Coatings. , 2000 .

[17]  H. Yamane,et al.  High-Temperature Neutron Diffraction Study of Y4Al2O9☆ , 1998 .

[18]  C. Jacobsen,et al.  Formation of New Compounds Ln4Al2O9 in the Ln2O3.Al2O3 System (Ln = La, Pr, Tb) , 1996 .

[19]  Liu Yanxu,et al.  Thermal properties of La3TaO7 and La2AlTaO7 oxides , 2017 .

[20]  F. Ye,et al.  Improved Toughness and Thermal Expansion of Non-stoichiometry Gd2 − xZr2 + xO7 + x/2 Ceramics for Thermal Barrier Coating Application , 2016 .

[21]  H. Elsayed,et al.  In-situ sintering reaction of Al2O3–LaAl11O18–ZrO2 composite , 2016 .