摘要
利用凝胶注模成型方法在6 T的纵向强磁场中制备出素坯,经磁场外无压烧结获得a轴或b轴取向的氮化硅陶瓷,研究了浆料在磁场中的聚合开始时间对氮化硅陶瓷织构度发展的影响,进而分析了烧结温度对烧结体织构化和各向异性线收缩的影响。研究表明:聚合开始时间从6 min增加到15 min,得到的织构化氮化硅陶瓷的取向因子从0.47增加到0.72,随着时间的继续延长,样品的织构度没有进一步增加。随着烧结温度的增加,氮化硅陶瓷的织构度不断增大,样品的各向异性线收缩现象越来越明显。利用凝胶注模工艺在强磁场中制备织构化陶瓷材料,选择合适的凝胶聚合开始时间对于获得高织构度的陶瓷是十分必要。
The a or b-axis textured Si_3N_4 ceramics were prepared by a gel-casting method in the magnetic field of 6 T and subsequently pressureless sintering. The effect of the initial time of polymerization on texture formation of Si_3N_4 ceramics was analyzed. And the effect of sintering temperature on the degree of texture and linear shrinkage anisotropy in samples was studied. The results show that the lotgering orientation factor of textured Si_3N_4 ceramics increases from 0.47 in 6 min to 0.72 in 15 min when the initial time of polymerization increases. With the further increasing of this time, the degree of texture in sample does not increase. The increasing of sintering temperature promotes the increasing of texture in samples, and consequently shrinkage anisotropy phenomenon of the sample is gradually obvious. During the process of preparing textured ceramics together with the gel-casting method in a strong magnetic field, it is necessary for obtaining the high degree of texture to choose the suitable initial time of polymerization.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2015年第S1期286-290,共5页
Rare Metal Materials and Engineering
基金
国家自然科学基金重点项目(50902140)
上海市科委项目(13DZ1108200
135211011020)
关键词
聚合开始时间
凝胶注模成型
强磁场
氮化硅
织构化
the initial time of polymerization
gel-casting method
strong magnetic field
silicon nitride
texture
