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目的 研究 GI- 型渗透陶瓷氧化铝坯体和烧结体的孔隙特征 ,分析其氧化铝多孔结构的形成机理和在渗透陶瓷增强补韧中的作用。方法 用 BI- XDC粒度分析仪分析氧化铝粉体粒度的质量组成 ,压汞法测试氧化铝坯体和 112 5℃烧结的氧化铝烧结体的开孔孔隙分布特征 ,扫描电镜观察氧化铝烧结前后的微观结构。结果 氧化铝粉体细颗粒分布在 0 .0 9～ 0 .1μm,0 .2～ 0 .5 μm,粗颗粒主要分布在 1.5～ 4.5 μm,在质量上以粗颗粒为主。氧化铝坯体中孔隙在烧结后增大。坯体中孔隙半径集中在 0 .2 5 31μm,烧结体中孔隙半径集中在 0 .30 81μm;平均半径由 0 .0 95 6 μm变为 0 .110 2 μm。扫描电镜观察烧结后的氧化铝中的小颗粒相互部分融合 ,而大颗粒无此现象。结论 氧化铝粒度组成有利于形成多孔可渗透氧化铝结构。这种多孔结构既是 GI- 型渗透陶瓷的形态骨架 ,也是力学骨架 ,是提高渗透陶瓷复合体力学性能的关键。
OBJECTIVE To study the pore characteristics of GI-type infiltrated ceramic alumina bodies and sintered bodies, and to analyze the formation mechanism of the porous structure of alumina and its role in strengthening toughening of infiltrated ceramics. Methods The particle size of alumina powder was analyzed by BI-XDC particle size analyzer. The pore distribution of the alumina billet and the sintered alumina sintered at 112 ℃ were tested by mercury intrusion technique. The distribution of pore before and after alumina sintering The microstructure. Results The fine particles of alumina powder were distributed in the range of 0. 0 ~ 0 ~ 1 μm and 0 ~ 2 ~ 0. 5 μm. The coarse particles were mainly distributed in 1.5 ~ 4.5 μm. The pores in the alumina body increase after sintering. The radius of the pores in the green body is concentrated at 0.525 μm, the pore radius in the sintered body is concentrated at 0.30811 μm, and the average radius is changed from 0.0956 μm to 0.1110 2 μm. Scanning electron microscopy showed that the small particles in the sintered alumina partially fuse with each other, whereas the large particles do not. Conclusion The alumina particle size composition favors the formation of a porous, permeable alumina structure. This porous structure is not only the morphological framework but also the mechanics framework of GI-type infiltrated ceramic, which is the key to improve the mechanical properties of infiltrated ceramic composites.