Thermal and Mechanical Properties Optimization of ABO4 Type EuNbO4 By the B-Site Substitution of Ta  

作　　者：Lin Chen Jing Feng 

机构地区：[1]Faculty of Material Science and Engineering,Kunming University of Science and Technology,Kunming 650093,China

出　　处：《Engineering》2020年第2期178-185,共8页工程（英文）

基　　金：under the support of the Natural Science Foundation of China(51762028 and 91960103);the Materials Genome Engineering of Rare and Precious Metal of Yunnan Province(2018ZE019).

摘　　要：Ferroelastic ABO4 type RETaO4 and RENbO4 ceramics(where RE stands for rare earth)are being investigated as promising thermal barrier coatings(TBCs),and the mechanical properties of RETaO4 have been found to be better than those of RENbO4.In this work,B-site substitution of tantalum(Ta)is used to optimize the thermal and mechanical properties of EuNbO4 fabricated through a solid-state reaction(SSR).The crystal structure is clarified by means of X-ray diffraction(XRD)and Raman spectroscopy;and the surface microstructure is surveyed via scanning electronic microscope(SEM).The Young’s modulus and the thermal expansion coefficient(TEC)of EuNbO4 are effectively increased;with respective maximum values of 169 GPa and 11.2×10^-6 K^-1(at 1200℃).The thermal conductivity is reduced to 1.52 W·K^-1·m^-1(at 700℃),and the thermal radiation resistance is improved.The relationship between the phonon thermal diffusivity and temperature was established in order to determine the intrinsic phonon thermal conductivity by eliminating the thermal radiation effects.The results indicate that the thermal and mechanical properties of EuNbO4 can be effectually optimized via the B-site substitution of Ta,and that this proposed material can be applied as a high-temperature structural ceramic in future.

关 键 词：THERMAL barrier coatings RARE earth NIOBATES SUBSTITUTION THERMAL conductivity THERMAL expansion COEFFICIENTS Young’s MODULUS 

分 类 号：TQ174.1[化学工程—陶瓷工业]