新型热障涂层材料Y_2Hf_2O_7的热性能  

Thermal Property of Y_2Hf_2O_7 Ceramic for Thermal Barrier Coatings

作　　者：杜仲[1] 王全胜[1] 马壮[1] 李云凯[1] 柳彦博[1] 

机构地区：[1]北京理工大学,北京100081

出　　处：《稀有金属材料与工程》2011年第S1期268-270,共3页Rare Metal Materials and Engineering

摘　　要：以HfO2和Y2O3为原料,采用固相法制备出Y2Hf2O7陶瓷粉体,经过造粒处理后通过等静压、高温烧结等工艺制备陶瓷试样块体。利用热膨胀仪测量Y2Hf2O7材料的热膨胀系数,采用激光脉冲法测量热扩散率,通过计算得到Y2Hf2O7材料的热导率。结果表明,Y2Hf2O7的热膨胀系数在400~1300℃范围下与YSZ材料相当;其热导率在200~1200℃范围内远低于传统的YSZ热障涂层材料。这是因为无机非金属材料传热机理为声子导热,且主要由声子平均自由程控制,而Y2Hf2O7较YSZ具有更多的氧空位,会导致声子散射增强,降低热导率。因此,Y2Hf2O7较YSZ具有更优良的综合热性能。The Y2Hf2O7 ceramic powder for thermal barrier coatings was prepared by solid state sintering; the phase structure, thermal expansion coefficient and thermal conductivity of the material were investigated. XRD results revealed that Y2Hf2O7 is single phase fluorite structure. With the temperature increasing, the thermal expansion coefficient (TEC) of the ceramic increased slowly, and the thermal conductivity decreased slightly at the same time. The thermophysical results indicated that the thermal conductivity of the Y2Hf2O7 ceramic was much lower than that of YSZ. The lower thermal conductivity of Y2Hf2O7 was mainly attributed to more oxygen vacancies and larger atomic weight of substitutional atom. These results imply that Y2Hf2O7 has better integrated thermal property than YSZ.

关 键 词：Y2Hf2O7 热膨胀系数 热导率 声子导热 

分 类 号：TQ174.1[化学工程—陶瓷工业]