Cyclic cold isostatic pressing and improved particle packing of coarse grained oxide ceramics for refractory applications
Cyclic cold isostatic pressing and improved particle packing of coarse grained oxide ceramics for refractory applications
复制标题
DOI：
10.1016/j.ceramint.2018.02.106
复制
发表时间：
2018-06
影响因子：
5.2
通讯作者：
S. Schafföner;J. Fruhstorfer;Susann Ludwig;C. Aneziris
中科院分区：
文献类型：
--
作者：
S. Schafföner;J. Fruhstorfer;Susann Ludwig;C. Aneziris
本研究以循环加压或最大压力循环方式，探讨粗粒氧化铝耐火材料之冷等静压成型。此外，还分析了最大压力和粒度分布对材料物理、力学和热机械性能的影响。循环压力增加导致表观密度略高，表观孔隙度略低。在最大压力下的循环在一定程度上降低了中值孔径。值得注意的是，优化的粒度分布导致较低的表观孔隙率，较低的中值孔径和较高的杨氏模量之前和之后的热冲击与稍微较低的相对降低的杨氏模量。较高的压制压力，降低显气孔率不影响杨氏模量。因此，显然，优化的粒度分布改善了与较小的中值孔径相关的颗粒堆积。这种较小的孔径增加了相对于总孔隙率的孔的数量，其然后充当裂纹起始点和裂纹偏转点，在热冲击的情况下限制扩展裂纹的长度。因此，定制的孔径分布是一个有前途的起点，以改善耐火材料的热机械性能。
This study investigated the cold isostatic pressing of coarse grained alumina refractories applying either a cyclic pressure increase or a cycling at maximum pressure. Additionally the effects of the maximum pressure and the particle size distribution on physical, mechanical and thermomechanical properties were analyzed. The cyclic pressure increase resulted in a slightly higher apparent density and lower apparent porosity. A cycling at maximum pressure decreased the median pore size to some extent. Remarkably, an optimized particle size distribution resulted in a lower apparent porosity, lower median pore size and in a higher Young's modulus before and after thermal shock together with a slightly lower relative decrease of the Young's modulus. A higher pressing pressure which decreased the apparent porosity did not affect the Young's modulus. Thus, apparently the optimized particle size distribution improved the particle packing which was associated with a smaller median pore size. This smaller pore size increased the number of pores relative to the total porosity, which then acted as points of crack initiation and crack deflection limiting the length of propagating cracks in case of thermal shock. Thus, tailoring the pore size distribution is a promising starting point to improve the thermomechanical properties of refractories.