Evolutions of mechanical and thermal properties of TmNbO_(4)/Tm_(3)NbO_(7) composites as protective coating materials  

作　　者：Jiankun Wang Lin Chen Baihui Li Hao Xu Xiang Jiang Jing-Feng Li Jing Feng 

机构地区：[1]Faculty of Materials Science and Engineering,Kunming University of Science and Technology,Kunming 650093,China [2]Southwest United Graduate School,Kunming 650092,China [3]State Key Laboratory of New Ceramics and Fine Processing,School of Materials Science and Engineering,Tsinghua University,Beijing 100084,China

出　　处：《Journal of Advanced Ceramics》2024年第11期1771-1785,共15页先进陶瓷（英文）

基　　金：support from Yunnan Major Scientific and Technological Projects(No.202302AG050010);the General Project in Yunnan Province(Nos.202201AT070192 and 202101BE070001-011);the Open Project of Yunnan Precious Metals Laboratory(No.2023050240);the Yunnan Fundamental Research Projects(No.202201BE070001-008);Project of Innovation Team in Yunnan Province(No.202305AS350018).

摘　　要：High fracture toughness,low thermal conductivity,and thermal expansion coefficient(TEC)matching substrate are essential for thermal barrier coatings(TBCs)and abradable seal coatings(ASCs).In this work,TmNbO_(4)/Tm_(3)NbO_(7) composites are designed and synthesized to increase their fracture toughness(KIC)and thermal insulation performance.Compared with those of TmNbO_(4)(KIC=2.2±0.1 MPa·m^(1/2))and Tm_(3)NbO_(7)(KIC=1.7±0.2 MPa·m^(1/2)),the increments in fracture toughness are as high as 50.0%and 91.1%,respectively.The highest toughness reaches 3.3±0.4 MPa·m^(1/2),which is attributed to the superior combination of grains between TmNbO_(4) and Tm_(3)NbO_(7),as well as the simultaneous effects of microcracks and crack bridging and bifurcation.Accurate estimation of the effect of the interfacial thermal resistance on the thermal conductivity at low temperatures was achieved using the minimum interfacial thermal resistance model.A novel method is proposed to inhibit radiative heat transfer by utilizing oxides with glass-like thermal conductivity to suppress thermal radiation.Consequently,the TmNbO_(4)/Tm_(3)NbO_(7) composite maintains a low thermal conductivity(1.19–2.02 W·m^(−1)·K^(−1))at 1000°C.The high TECs(10.4×10^(−6)–11.8×10^(−6)·K^(−1) at 1500°C)and excellent high-temperature stability ensure that the designed TmNbO_(4)/Tm_(3)NbO_(7) composites can be used at temperatures reaching 1500°C.Accordingly,simultaneous enhancement of fracture toughness and thermal insulation in TmNbO_(4)/Tm_(3)NbO_(7) composites is effective,and the revealed mechanisms are useful for various materials.

关 键 词：thermal barrier coatings(TBCs) toughening mechanisms COMPOSITES thermal conductivity thermal expansion thermal radiation 

分 类 号：TB30[一般工业技术—材料科学与工程]