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Open Access Research Article Issue
Phase evolution and properties of novel Al2O3-based poly-hollow microsphere (PHM) ceramics
Journal of Advanced Ceramics 2016, 5 (2): 176-182
Published: 01 June 2016
Downloads:37

In this paper, novel Al2O3-based poly-hollow microsphere (PHM) ceramics were prepared using Si3N4 and Al2O3 PHMs as pore-forming agents. The effect of Si3N4 and Al2O3 PHMs with different percentages on properties of Al2O3-based PHM ceramics was investigated. Through adjusting percentage of Al2O3 PHMs, Al2O3-based PHM ceramics with enhanced properties are achieved. X-ray diffraction (XRD) results show that main phases of Al2O3-based PHM ceramics vary from β-SiAlON (z value increases from 2.9 to 4) to Al2O3 with the increase of percentage of Al2O3 PHMs from 10% to 100%. The different phase compositions result in different properties of Al2O3-based PHM ceramics. With the increase of percentage of Al2O3 PHMs, porosity of Al2O3-based PHM ceramics gradually decreases, while their shrinkage, flexural strength, and fracture toughness firstly decrease and then increase. Using different kinds of ceramic PHMs as pore-forming agents, various novel and high-performance porous ceramics could be prepared via optimizing percentage of ceramic PHMs in the future.

Open Access Research Article Issue
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
Published: 21 September 2015
Downloads:18

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.

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