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  

Sintering kinetics and mechanisms of alumina matrix ceramic materials toughened by diopside and AlTiB

作　　者：刘长霞[1] 孙军龙[1] 张希华[2] 王保卫[1] 

机构地区：[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

出　　处：《粉末冶金技术》2009年第4期251-254,258,共5页Powder Metallurgy Technology

基　　金：鲁东大学引进人才基金(LY20074303)和(LY20074302);山东省自然科学基金(Y2007F29)

摘　　要：研究了透辉石/AlTiB增韧补强Al2O3基陶瓷材料的无压烧结致密化过程,通过绘制lg(ΔL/L0)-lgt图,用最小二乘法计算了透辉石/AlTiB增韧补强Al2O3基陶瓷材料的表观激活能。计算结果表明:纯Al2O3致密化机制为扩散机制控制;透辉石/AlTiB增韧补强Al2O3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/AlTiB增韧补强Al2O3基陶瓷材料的烧结动力学方程;纯Al2O3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/AlTiB增韧补强Al2O3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,也有晶界扩散。Sintering densification process 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 be controlled by diffusion mechanisms, and that of alumina matrix ceramic materials toughened by diopside and AITiB may be the flow of liquid phases and rearrangement of grains in 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 （ n = 2.5） , and that of alumina matrix ceramic materials toughened by diopside and AITiB may be volume diffusion and grain boundary diffusion （2.5 〈n 〈3.0）.

关 键 词：氧化铝 铝钛硼 烧结动力学 烧结机制 

分 类 号：TQ174.758[化学工程—陶瓷工业] TG146.21[化学工程—硅酸盐工业]