porous Si3N4 ceramics, Si3N4 poly-hollow microspheres (PHMs), solid loading, aqueous gelcasting, mechanical properties
Porous Si3N4 ceramics were prepared by aqueous gelcasting using Si3N4 poly-hollow microspheres (PHMs) as pore-forming agent. The effects of solid loading of Si3N4 slurry and Si3N4 PHM content on the properties of porous Si3N4 ceramics were investigated. Only β-Si3N4 phase is observed in porous Si3N4 ceramics, and Si3N4 PHMs distribute uniformly both in Si3N4 green samples and porous Si3N4 ceramics. Results show that solid loading of Si3N4 slurry and Si3N4 PHM content could considerably influence the properties of porous Si3N4 ceramics. With the increase of solid loading of Si3N4 slurry (decrease of Si3N4 PHM content), the distributing state of Si3N4 PHMs changes from contacting with each other to just embedding in the matrix, thus their porosity decreases, while their shrinkage, flexural strength, and fracture toughness increase.
Tsinghua University Press
Jia-Min WU, Xiao-Yan ZHANG, Jie XU et al. Preparation of porous Si3N4 ceramics via tailoring solid loading of Si3N4 slurry and Si3N4 poly-hollow microsphere content. Journal of Advanced Ceramics 2015, 4(4): 260-266.