Fe2O3对原位制备SiCw/SiC太阳能储热陶瓷的结构与性能的影响  

Fe2O3 on In-situ Synthesized SiCw/SiC Composite Ceramics for Solar Thermal Energy Storage

作　　者：徐晓虹[1] 田江洲 吴建锋[1] 张乾坤[1] 金昊[1] 杜怿鑫 XU Xiao-Hong;TIAN Jiang-Zhou;WU Jian-Feng;ZHANG Qian-Kun;JIN Hao;DU Yi-Xin(School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China)

机构地区：[1]武汉理工大学材料科学与工程学院

出　　处：《无机材料学报》2019年第10期1103-1108,共6页Journal of Inorganic Materials

基　　金：国家重点研发计划(2018YFB1501002)~~

摘　　要：为调控SiCw/SiC复相陶瓷中原位生长SiC晶须的生长发育和形貌,以提高SiC复相储热陶瓷的性能,在CF0配方(SiC 69.31wt%, AlN 20.30wt%, Si 10.39wt%)的基础上添加0.5wt%~2.0wt%Fe2O3作为催化剂。研究了Fe2O3对晶须形貌、生长机制及SiC复相陶瓷结构与性能的影响。研究结果表明,引入Fe2O3后晶须生长机制由气–固机理转变为气–液–固机理。Fe2O3添加量通过调节C元素在Fe-Si熔球中的溶解度,与烧成温度共同调控晶须形貌。经1500℃烧成的CF4(2.0wt%Fe2O3)样品性能最佳,晶须直径50~100 nm,长度1~6μm,其体积密度、抗折强度、比热容分别为2.19 g/cm^3、45.08 MPa、0.95 J/(g·K)(25℃),热导率达18.15 W/(m·K)(25℃),相比于未添加Fe2O3的样品增加了169%。气-液-固机理生长的SiC晶须缺陷少、直径大,可有效降低晶须–基体传输势垒,具有更好的热学性能。In order to improve solar thermal storage properties of the SiCw/SiC composite ceramics, in-situ growth and morphology of SiC whiskers(SiCw) were controlled by adding catalyst Fe2O3(0.5 wt%–2.0 wt%) on the basis of formula CF0(SiC 69.21 wt%, AlN 20.30 wt%, Si 10.39 wt%). Effect of Fe2O3 on morphology of SiCw as well as growth mechanism and properties of SiC composite ceramics were analyzed. Results indicated that SiCw growth mechanism changed from vapor–solid to vapor–liquid–solid after adding Fe2O3. The addition of Fe2O3 via adjusting solubility of C element into Fe-Si droplets, as well as firing temperature jointly controlled morphology of SiCw. The sample CF4(Fe2O3 2.0 wt%) fired at 1500 ℃ with whiskers diameter of 50–100 nm and 1–6 μm in length obtained optimal performance, the bulk density, bending strength, heat capacity and thermal conductivity were 2.19 g/cm^3, 45.08 MPa, 0.95 J/(g·K)(25 ℃), 18.15 W/(m·K)(25 ℃), respectively. The value of thermal conductivity increased by 169% compared to the sample without Fe2O3. The few defects and large-diameter of whisker grown by vapor–liquid–solid mechanism could improve thermal properties by reducing the matrix-whisker thermal barrier.

关 键 词：FE2O3 SIC晶须 SiCw/SiC复相陶瓷 太阳能储热 

分 类 号：TQ174[化学工程—陶瓷工业]