Author: Wu Haibo Yan Yongjie Liu Guilin Liu Xuejian Zhu Yunzhou Huang Zhengren Jiang Dongliang Li Yinsheng
Publisher: Blackwell Publishing
E-ISSN: 1744-7402|12|5|976-984
ISSN: 1546-542X
Source: International Journal of Applied Ceramic Technology, Vol.12, Iss.5, 2015-09, pp. : 976-984
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Abstract
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·m1/2 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.