Mullite whiskers prepared by molten salt method using Si powders  

作　　者：Wei WANG Hongwei LI Yajie GUO Qiang SUN Chen CHEN 

机构地区：[1]Department of Chemical Engineering,College of Environment Science and Engineering,Chang’an University,Xi’an 710054,China [2]College of Materials Science and Engineering,Chang’an University,Xi’an 710061,China

出　　处：《Journal of Advanced Ceramics》2012年第4期283-289,共7页先进陶瓷（英文）

基　　金：the Fundamental Research Funds for the Central Universities(CHD2009JC143);the Open Fund of State Key Laboratory for Mechanical Behavior of Materials(201011004).

摘　　要：Mullite whiskers were prepared from Si powders in molten Al2(SO4)3-Na2SO4 mixture salts with different Al/Si molar ratio(R)of raw materials.The resulting mullite whiskers,had been investigated using X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive spectrometer(EDS)and infrared spectroscopy analysis(FT-IR).Mullite phase was obtained in molten salts when the temperature reached at 850℃.SEM and EDS results revealed that two kinds of microstructures were formed in the final product,Al-rich mullite pellets and clusters of tiny mullite crystals,and the content of Al-rich mullite pellets increased with the higher Al/Si molar ratio(R)adopted in raw materials.A new oxidation-dissolution mechanism was proposed to explain mullite whiskers growth.According to thermodynamic analysis,mullite phase might be spontaneously formed as the temperature reached the decomposition temperature of aluminum sulfate(1023 K).

关 键 词：chemical preparation WHISKERS MULLITE infrared spectroscopy 

分 类 号：TB3[一般工业技术—材料科学与工程]