透辉石AlTiB增韧补强氧化铝基陶瓷材料烧结动力学和烧结机制.pdf

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第27卷第4期
粉末冶金技术
2009年8月
Powder Metallurgy Technology
1ug.2009
透辉石/ ATIB増韧补强氧化铝基陶瓷材料
烧结动力学和烧结机制
刘长霞“?孙军龙”张希华2王保卫)
1)(鲁东大学先进制造与自动化技术重点实验室,山东烟台264025)
2)(山东大学材料科学与工程学院,济南250061)
摘要:研究了透辉石∥AITB増韧补强A2O3基陶瓷材料的无压烧结致密化过程,通过绘制g(△L/L。)gt
图,用最小二乘法计算了透辉石/AITB增韧补强A2O3基陶瓷材料的表观激活能。计算结果表明:纯Al2O
致密化机制为扩散机制控制;透辉石/ ATIB增韧补强Al2O基陶瓷材料在烧结初期的致密化机制为液相流动
和颗粒重排,在中、后期致密化机制转为扩散机制控制。根据烧结温度和保温时间对复合材料线收缩率的影
响,建立了透辉石/ ATIB增韧补强Al203基陶瓷材料的烧结动力学方程;纯A203陶瓷材料的烧结特征指数n
约为2.5,其烧结过程中的物质迁移机制由体扩散控制;透辉石/ ATIB增韧补强A203基陶瓷材料的烧结特
征指数n值介于2.5与3.0之间,其在烧结中、后期的物质迁移机制既有体扩散,也有品界扩散。
关键词:氧化铝;铝钛硼;烧结动力学;烧结机制
Sintering kinetics and mechanisms of alumina matrix ceramic
materials toughened by diopside and AITIB
Liu Chang
Sun Junlong, Zhang Xih
Wang Baowei
1)(Key Laoratory of Advaneed Manufacturing and Automation Technology, Ludong University, Yantai 264025, China
2)(School of Materials Science and Engineering. Shandong University, Ji'nan 250061, China)
Abstract Sintering densification proecss of alumina matrix ceramic materials toughened by diopside and AITIB were
studied in this paper. The apparent activated energy was calculated by using the method of least squares. Results
show that the densification of pure alumina may e controlled by diffusion mechanisms, and that of alumina matrix
ceramic materials toughened by diopside and ALTIB may be the flow of liquid phases and rearrangement of grains i
initial stages of the sintering process. However, the densification mechanism turns to diffusion control in the later
sintering process. The sintering kinetic equations were deduced according to the influences of sintering temperature
and holding time on linear shrinkage rate of the new fabricated composites. The sintering mechanisms were analyzed
by comparing the characteristic exponent n. It is indicated that the main sintering mechanism of pure alumina may be
volume diffusion (2=2. 5), and that of alumina matrix ceramic materials toughened by diopside and AITIB may be
volume diffusion and grain boundary diffusion(2. 5 Key words: alumina; ALTIB; sintering kinetic; sintering mechanism
陶瓷制品的烧结,是其制备过程中的一个重要能的一个过程。对陶瓷烧结理论的研究已有近百年
环节,是其在高温下通过一系列内部物理化学过程,的历史,自从 Kuczynski开创烧结理论以来,多种
获得一定密度、微观结构、抗弯强度和断裂韧度等性烧结理论与模型相继被提出2-“1。Al2O,陶瓷是
*鲁东大学引进人オ基金(LY20074303)和(ILY20074302);山东省自然科学基金(Y2007F29
**刘长霞(1978-),女,讲师。Email:hester5371@yahoo.com.cn
收稿日期:2008-05-08