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Studies on processing of layered oxide‐bonded porous sic ceramic filter materials
Author(s) -
Dey Atanu,
Kayal Nijhuma,
Chakrabarti Omprakash,
Fortes Nilo M.,
Innocentini Murilo D. M.,
Molla Atiar R.,
Sinha Prasanta,
Dalui Srikanta
Publication year - 2021
Publication title -
international journal of applied ceramic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 57
eISSN - 1744-7402
pISSN - 1546-542X
DOI - 10.1111/ijac.13717
Subject(s) - materials science , mullite , porosity , composite material , ceramic , sintering , microstructure , oxide , metallurgy
Oxide‐bonded porous SiC ceramic filter supports were prepared using SiC powder ( d 50 = 212 µm), Al 2 O 3 , and clay as bond forming additives and graphite as pore former following reaction bonding of powder compacts at 1400°C in air. Reaction bonding characteristics, phase composition, porosity, pore size, mechanical strength, and microstructure of porous SiC ceramic supports were investigated. Mullite bond phase formation kinetics was studied following the Johnson–Mehl–Avrami–Kolmogorov (JMAK) model using non‐isothermal differential thermal analysis (DTA) data. Compared to porous SiC ceramic filter supports having no needle‐like mullite bond phase, materials processed by the mullite bonding technique exhibited higher average strength (22.1%) and elastic modulus (5.4%) at a similar porosity level of ~38%, with upper and lower bounds of their strength, modulus, and porosity being 39.1 MPa, 40.2 GPa, and 36.3% and 34.2 MPa, 31.3 GPa, and 33.0%, respectively. Spray coating method was applied for preparation of oxidation‐bonded SiC filtration layer having thickness of ~150 µm and pore size of ~5–20 µm over the porous SiC support compacts using aqueous slurry made of fine SiC powder ( d 50 = 15 µm) followed by sintering. The layered ceramics thus prepared are potential materials for gas filter applications.