Yttrium tantalate(YTa04)is the next generation of higher service temperature thermal barrier coatings(TBCs)materials due to its smaller volume effect in phase change,lower thermal conductivity and unique ferroelastic domain structure.However,the low fracture toughness limits its application.We first char-acterized the diffraction patterns of variants,and two variants(M1 and M2)observed in transmission electron microscopy(TEM)results were determined from four possible variants by mechanical deriva-tion.The role of Zr4+doping in ferroelastic toughening was explained in detail.With the increase of Zr4+doping concentration,the monoclinic angle β and the domain rotation angle α decrease,respectively.The spontaneous strain component and the principal strain in the main space also have a similar decreasing trend.The decrease of the ferroelastic domain inversion energy barrier is beneficial to the improvement of fracture toughness.Combining the results of Vickers indentation,we found that Zr4+could be enriched at the domain boundary to inhibit the generation of cracks.An appropriate amount of Zr4+is conducive to the improvement of fracture toughness,and the excessive Zr4+will reduce the fracture toughness due to the generation of by-product t-ZrO2.So,the optimal composition is Y0.44Ta0.44Zr0.1202 and the best fracture toughness(2.9-3.8MPa m1/2)is equivalent to the commercial 8YSZ.This result will promote the application of a new generation of TBCs.

Cheng Luo;Cong Li;Ke Cao;Junbao Li;Junhui Luo;Qinghua Zhang;QianQian Zhou;Fan Zhang;Lin Gu;Li Yang;Yichun Zhou

School of Materials Science and Engineering,Xiangtan University,Xiangtan 411105,China;School of Advanced Materials and Nanotechnology,Xidian University,Xi'an 710126,China;Frontier Research Center of Thin Films and Coatings for Device Applications,Academy of Advanced Interdisciplinary Research,Xidian University,Xi'an 710126,China;College of Engineering,BIC-ESAT,Peking University,Beijing 100871,China;Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China

材料科学技术（英文版）

[1]Cheng Luo;Cong Li;Ke Cao;Junbao Li;Junhui Luo;Qinghua Zhang;QianQian Zhou;Fan Zhang;Lin Gu;Li Yang;Yichun Zhou-.Ferroelastic domain identification and toughening mechanism for yttrium tantalate-zirconium oxide)[J].材料科学技术（英文版）,2022(32):78-88

Ferroelastic,tantalate,YTa04,Zr4+doping,Zr4+could,Zr4+is,Zr4+will,44Ta0,44Zr0

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