摘要
以中间相碳微球(MCMB)为造孔剂制备出高显气孔率的莫来石晶须框架(MWF),通过XRD、SEM和激光导热仪研究了MCMB对MWF的相组成、微观形貌以及热导率的影响。结果表明:以AlF3催化1300℃保温3 h煅烧时,MCMB引入量可实现MWF体积密度、显气孔率以及线膨胀率分别在0.25~0.92 g·cm^-3、67.3%~90.9%、-7.87%~14.18%范围调控,MCMB引入量与MWF体积密度呈线性关系,与线性膨胀呈指数关系;孔结构由晶须框架搭建的复杂曲折亚微米孔和分散的球状宏孔组成;热导系数随温度升高而略增,其室温导热符合Maxwell-Eucken1导热模型。
Mullite whisker framework(MWF)with high apparent porosity was prepared by using mesocarbon microbeads(MCMB)as pore-former.The effect of MCMB on phase composition,microstructure and thermal conductivity of MWF were studied by XRD,SEM and flash thermal diffusivity instrument.The results show that the bulk density,apparent porosity and linear expansion rate at 0.25~0.92 g·cm^-3,67.3%~90.9%and-7.87%~14.18%respectively can be well controlled by the content of MCMB when MMW calcined at 1300℃for 3 h.The bulk density of WMF displays linear improvement with content of MCMB,but linear expansion rate exhibits exponential growth.The pore mostly consists of complex tortuous submicron pores among mullite whiskers isoloacted spherical macrospores from MCMB.Thermal conductivity coefficient of MWF slightly increases as the temperature rises,and the thermal conductivity at room temperature meets the Maxwell-Eucken1 thermal conductivity model.
作者
李红伟
高莹
曾德军
LI Hongwei;GAO Ying;ZENG Dejun(School of Materials Science and Engineering,Chang'an University,X i'an 710054,China)
出处
《中国陶瓷》
CAS
CSCD
北大核心
2019年第12期27-32,共6页
China Ceramics
基金
国家自然科学基金(51202015)
陕西省自然科学基金(2018GQ5120)
长安大学中央高校基金(300102318107)
关键词
莫来石晶须
中间相碳微球
微孔形貌
热导率
Mullite whiskers
Mesocarbon microbeads
Pore Morphology
Thermal Conductivity