先驱体浸渍-裂解法制备高密度再结晶碳化硅  

DENSIFICATION OF RECRYSTALLIZED SILICON CARBIDE PREPARED BY PRECURSOR IMPREGNATION AND PYROLYSIS PROCESS

作　　者：郭文明[1] 肖汉宁[1] 雷海波[1] 谢文[1] 

机构地区：[1]湖南大学材料科学与工程学院,长沙410082

出　　处：《硅酸盐学报》2010年第8期1514-1518,共5页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(50972042)资助项目

摘　　要：分别采用聚碳硅烷(polycarbosilane,PCS)/二甲苯(xylene)溶液和SiC/PCS/xylene浆料浸渍-裂解(precursor impregnation and pyrolysis,PIP)法制备高密度再结晶碳化硅(recrystallized SiC,RSiC)。测量了RSiC的体积密度和抗弯强度。用扫描电镜观察了RSiC样品的显微结构。结果表明:采用PCS/xylene溶液浸渍的裂解产物均匀分布在RSiC的孔隙中,经6次PIP循环后,RSiC的密度从2.74g/cm3提高到约2.90g/cm3,抗弯强度与初始样品相比提高了28.1%。采用SiC/PCS/xylene浆料浸渍后的产物在基体中呈梯度分布,基体表层孔隙填充致密,有利于提高RSiC的抗氧化能力。仅3次PIP循环后,RSiC的密度就可达2.90g/cm3,抗弯强度也可提高37.0%。The dense recrystallized SiC （RSiC） materials were prepared by a precursor impregnation and pyrolysis （PIP） process us-ing polycarbosilane （PCS）/xylene solution and SiC/PCS/xylene slurry as impregnated agents,respectively. The density and bending strength of RSiC were measured,and its microstructures were observed by scanning electron microscopy. The results show that the pyrolysis products via PCS/xylene solution are distributed homogeneously in the pores of RSiC,and with 6 PIP cycles its density increases from the original density of 2.74 g/cm3 to about 2.90 g/cm3,as a result,its bending strength increases by 28.1% compared to that of original RSiC. However,the pyrolysis products via SiC/PCS/xylene slurry have a gradient distribution,namely condensation in exterior and loose distribution in interior,which might improve the oxidation resistance of RSiC. With only 3 PIP cycles via SiC/PCS/xylene slurry,the density of ceramic reaches to 2.90 g/cm3,and its bending strength should be increased by 37.0% accordingly.

关 键 词：再结晶碳化硅 浸渍-裂解法 聚碳硅烷 致密化 

分 类 号：O482.3[理学—固体物理]