多孔莫来石陶瓷制备与性能研究

Preparation and properties of porous mullite ceramics

为了改善多孔莫来石陶瓷结构与力学性能,以d 50=11.48μm的氧化铝微粉和d 50=26.84μm的分析纯SiO 2为原料,分别添加V2O5、含锆陶瓷纤维及炭黑,通过固相烧结法制得了莫来石多孔陶瓷。采用XRD、SEM等研究了温度、催化剂含量、陶瓷纤维以及炭黑的引入对莫来石多孔陶瓷结构与性能的影响。结果表明:V2O5的添加促进了莫来石的生长,降低了试样的体积密度;引入含锆陶瓷纤维,在V2O5液相的辅助作用下,形成了陶瓷纤维-莫来石晶须多级结构,显著提高了试样的耐压强度;炭黑的氧化为莫来石晶须提供了生长空间,有助于增大试样气孔率,降低体积密度。

In order to improve the structure and mechanical properties,porous mullite ceramics were prepared by solid phase sintering using alumina fine powder(d 50=11.48μm)and analytically pure SiO 2(d 50=26.84μm)as raw materials,and adding V 2O 5,zirconium-containing ceramic fibers and carbon black,respectively.The effects of the temperature,the catalytic agent content,the ceramic fiber and carbon black addition on the structure and properties of porous mullite ceramics were investigated by XRD and SEM.The results show that the addition of V 2O 5 promotes the growth of mullite and reduces the bulk density of the specimens;the introduction of the zirconium-containing ceramic fibers helps to form ceramic fiber-mullite whisker multi-stage structure with the aid of V 2O 5 liquid phase,significantly improving the compressive strength of the specimens;the oxidation of carbon black provides growth space for the mullite whiskers,which helps to increase the porosity and reduce the bulk density of the specimens.