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In situ toughened two‐phase B 12 (C, Si, B) 3 –SiC ceramics fabricated via liquid silicon infiltration
Author(s) -
Sun Mengyong,
Bai Yuhang,
Li Mingxing,
Fan Shangwu,
Cheng Laifei
Publication year - 2019
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.16023
Subject(s) - materials science , ceramic , composite material , fracture toughness , in situ , silicon , toughening , toughness , infiltration (hvac) , metallurgy , physics , meteorology
In situ toughened B 12 (C, Si, B) 3 –SiC ceramics were successfully fabricated via the liquid silicon infiltration process. Two types of B 12 (C, Si, B) 3 phases, with high and low Si contents, respectively, and plate‐like SiC particles were formed by the reaction between B 4 C and Si. The in situ toughening mechanism involved two effects: the multiple crack deflections caused by the increased grain boundaries, and the pullout and rupture of a significant amount of plate‐like SiC particles. Block ceramics with a high fracture toughness of 6.5 ± 0.5 MPa·m 1/2 were fabricated via the in situ toughening mechanism. A strong interface bond was present between the high‐ and low‐B 4 C‐content layers in the laminated ceramics, which led to residual compressive stress inside the materials. As a result, the laminated structural design enhanced the fracture toughness to 7.5 ± 0.5 MPa·m 1/2 .