温度对Al_2O_3-C材料中β-Sialon晶须形成的影响研究

Effect of Temperature on Formation of β-Sialon Whiskers in Al_2O_3-C Materials

本文研究了温度对Al2O3-C耐火材料中β-Si3Al3O3N5晶须形成的影响规律。研究发现:在弱还原性气氛下,Al2O3-Si-Al-C稳定存在的非氧化物物相为Al4C3、AlN、SiC和β-Sialon相。其中,催化作用下,Al2O3-C耐火材料中的金属Al在1000℃时转化为AlN,金属Si在1200℃时转化成SiC,在1400℃时有β-Sialon相生成;而无催化剂存在时,生成的物相仅为SiC和AlN相。催化作用下,AlN形貌呈短柱状;SiC呈晶须状,直径为亚微米级,且晶须有液点存在;β-Sialon相呈纳米晶须状。SiC和β-Sialon晶须的生长都符合气-液-固机理。

The effect of temperature on the synthesis of β-Si3Al3O3N5 whiskers have been researched in this paper.The results show that at the reducing atmosphere,the stable phases of Al4C3,AlN,SiC and β-Sialon existed in the system of Al2O3-Si-Al-C.Under the action of transition metal Ni as catalyst,metal of Al and Si in Al2O3-C refractories is respectively transferred into AlN and SiC.The corresponding temperature is respectively about 1000 ℃ and 1200 ℃.At 1400 ℃,the phase of β-Sialon is generated.Without any catalyst,only phases of SiC and AlN can be formed.Short column of AlN as well as whiskers of SiC and β-Sialon could be synthesized when the catalyst exists.The diameter of SiC whiskers and β-Sialon whisker is respectively about submicro and nano meter.The liquid drops in SiC and βSialon whiskers show the vapor-liquid-solid growth model.