摘要
在酸洗处理工艺有效改善氮化硅浆料流动性的研究基础上 ,本工作通过动态振荡测量的方法探讨了酸洗处理前后氮化硅浆料粘弹性的变化规律 .结果表明 :随着氮化硅浆料固相含量的提高 ,线性粘弹区的范围逐渐减小 ,相应的弹性储能模量G′值逐渐增大 .经酸洗处理的浆料的线性粘弹区扩大 ,相应的弹性储能模量G′值大幅度减小 .随着浆料固相含量的提高 ,体系的粘弹效应逐渐增大 ,特征频率ωc 逐渐减小 ,体系由粘性逐渐转化为弹性 .酸洗处理的氮化硅浆料在相对较高的固相含量时实现粘性到弹性的转变 .并借助结构弛豫时间tr的概念解释了浆料的粘弹模量对振荡频率的依赖关系 .
On the base of fluidity improvement, the effects of acid leaching on the viscoelastic properties of aqueous silicon nitride suspensions were investigated under oscillatory shear conditions. The experimental results indicate that the linear viscoelastic region narrows and the corresponding elastic storage modulus G ′ increases continuously with increasing solid concentration. After acid leaching, the linear viscoelastic region broadens and the corresponding G ′ decreases sharply. With increasing solids concentration, the magnitude of the viscoelastic response increases, the characteristic frequency ω c shifts toward lower frequencies and the suspension transforms from more viscous into more elastic. Moreover, the transformation takes place at higher solid concentrations after acid leaching. The frequency dependence of the viscoelastic properties of suspensions can be understood on the concept of the structural relaxation time t r.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2000年第4期361-364,共4页
Journal of The Chinese Ceramic Society
关键词
酸洗
氮化硅
浆料
粘弹性
陶瓷
acid leaching
silicon nitride
suspensions
viscoelasticity
