Wang H, Chao Y, Liao Y, Liang X, Zhu Z, Gao W
Department of Prosthodontics, School of Stomatology, WCUMS, Chengdu 610041, China.
Hua Xi Yi Ke Da Xue Xue Bao. 2001 Jun;32(2):264-6, 273.
This study was conducted to elucidate the mechanism of formation of porous structure by investigating the porosity of the alumina adobe and sintered body of GI-II Infiltrate Ceramic, and its role in strengthening and toughening this kind of ceramic composite.
The alumina powder size-mass distribution was obtained by BI-XDC powder size analysis device; the open pore parameters of alumina adobe and sintered body were analyzed using the mercury pressure method. Their fracture surfaces were observed under scanning electronic microscope.
Fine powder had two main size groups of 0.09-0.1 micron and 0.2-0.5 micron, respectively, and coarse powder, with size between 1.5 to 4.5 microns, occupied the majority of powder mass. Alumina adobe's pores became larger after sintering. The median pore radii of adobe and sintered body were 0.2531 micron and 0.3081 micron, respectively; the average pore radii changed from 0.0956 micron to 0.1102 micron. Under scanning electronic microscope, fine alumina powders were fused partially together and their surfaces were blunted, but coarse powders did not show such phenomena.
The alumina size distribution contributes to the formation of porous structure of alumina sintered body. This porous structure is not only the shape skeleton but also the mechanical skeleton of GI-II Infiltrated Ceramic. It plays an important role in raising the mechanical properties of this kind of ceramic composite.
通过研究GI-II渗透陶瓷的氧化铝坯体和烧结体的孔隙率，阐明其多孔结构的形成机制及其在增强和增韧这种陶瓷复合材料中的作用。
采用BI-XDC粒度分析仪获得氧化铝粉末的粒度-质量分布；采用压汞法分析氧化铝坯体和烧结体的开孔参数。在扫描电子显微镜下观察其断口表面。
细粉主要有0.09 - 0.1微米和0.2 - 0.5微米两个尺寸组，粗粉尺寸在1.5至4.5微米之间，占粉末质量的大部分。氧化铝坯体烧结后孔隙变大。坯体和烧结体的中值孔径分别为0.2531微米和0.3081微米；平均孔径从0.0956微米变为0.1102微米。在扫描电子显微镜下，细氧化铝粉末部分熔合在一起，表面变钝，但粗粉未出现这种现象。
氧化铝粒度分布有助于氧化铝烧结体多孔结构的形成。这种多孔结构不仅是GI-II渗透陶瓷的形状骨架，也是其力学骨架。它在提高这种陶瓷复合材料的力学性能方面起着重要作用。
