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Effects of Grain Grading on Microstructures and Mechanical Behaviors of Pressureless Solid‐State‐Sintered SiC
Author(s) -
Wu Haibo,
Yan Yongjie,
Liu Guilin,
Liu Xuejian,
Zhu Yunzhou,
Huang Zhengren,
Jiang Dongliang,
Li Yinsheng
Publication year - 2015
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.12409
Subject(s) - materials science , sintering , shrinkage , microstructure , pressureless sintering , ceramic , grain growth , fracture toughness , composite material , solid state , metallurgy , engineering physics , engineering
S‐SiC ceramics with >96% of densification degree were derived from 0.8‐ to 8.6‐μm graded powders for the first time after sintered at 2210°C. Grain grading generated a 21.8% increase in green density and a 40.8% decrease in sintering shrinkage (low to 12.2%). The introduction of micrometer‐sized coarse particles suppressed abnormal grain growth owing to their pinning effect, thus resulting in equiaxial grains. Dramatically improved fracture toughness peaked to 3.77 MPa·m 1/2 at 50 wt% of added coarse powder. Sintering mechanism of graded powders can be deduced as the bonding of coarse SiC particle through solid‐state sintering of fine powder.