LiAlO2为烧结助剂低温无压烧结制备致密Si3N4陶瓷  

Preparation of dense Si 3N 4 ceramics by low temperature pressureless sintering with LiAlO 2 as sintering aid

作　　者：郭昂 王战民[1] 赵世贤[1] 李凌锋 Guo Ang;Wang Zhanmin;Zhao Shixian;Li Lingfeng(State Key Laboratory of Advanced Refractories,Sinosteel Luoyang Institute of Refractories Research Co.,Ltd.,Luoyang 471039,Henan,China)

机构地区：[1]中钢集团洛阳耐火材料研究院有限公司先进耐火材料国家重点实验室,河南洛阳471039

出　　处：《耐火材料》2020年第3期191-195,共5页Refractories

基　　金：国家重点研发计划(2017YFB0310300)。

摘　　要：以高α相含量的Si3N4粉体为主要原料,LiAlO2作为烧结助剂,在1650℃无压烧结制备Si3N4陶瓷。研究LiAlO2烧结助剂含量(质量分数分别为6%、9%、12%、15%、18%)及保温时间(1、4、7、10 h)对Si3N4陶瓷试样的线收缩率、质量损失率、相对密度、相组成以及显微结构的影响。结果表明:LiAlO2能够显著降低Si3N4陶瓷的致密化温度。随着LiAlO2含量的增加,试样的相对密度先增大后减小,烧结助剂含量为12%(w)时相对密度达到97%以上。而β-Si3N4转化率随着LiAlO2含量的增加而升高。LiAlO2含量为12%(w),保温时间为4 h时,试样的相对密度达到最高。随着保温时间继续延长,相对密度略有降低。但β-Si3N4转化率则随着保温时间延长而不断升高。Si 3N 4 ceramics were prepared by pressureless sintering at 1650℃with highαphase content Si 3N 4 powder as the main raw material and LiAlO 2 as the sintering aid.The effects of the LiAlO 2 content(6%,9%,12%,15%,and 18%,by mass)and the soaking time(1,4,7,and 10 h)on the linear shrinkage,the mass loss and the relative density,the phase composition and the microstructure of the Si 3N 4 ceramics were analyzed.The results show that LiAlO 2 can play a significant role in reducing the densification temperature of the Si 3N 4 ceramics;with the increase of the LiAlO 2 content,the relative density of the specimens increases firstly and then declines,reaching 97%at the LiAlO 2 content of 12%;the conversion rate ofβ-Si 3N 4 increases with the increasing content of LiAlO 2;when the soaking time is 4 h and the LiAlO 2 content is 12%,the relative density of the specimens is the highest;the relative density decreases slightly with the further prolonging of the soaking time,but the conversion ofβ-Si 3N 4 increases with the prolonging of the soaking time.

关 键 词：SI3N4陶瓷 低温无压烧结 LiAlO2助烧剂 致密化 β-Si3N4转化率 

分 类 号：TQ175[化学工程—硅酸盐工业]