In situ toughened two‐phase B12(C, Si, B)3–SiC ceramics fabricated via liquid silicon infiltration. Issue 4 (6th September 2018)

• Record Type: Journal Article
• Authors: Sun, Mengyong; Bai, Yuhang; Li, Mingxing; Fan, Shangwu; Cheng, Laifei
• Is Part Of: Journal of the American Ceramic Society. Volume 102:Issue 4(2019)
• Page Start: 2094
• Page End: 2103
• Publication Date: 2018-09-06
• Subjects: boron carbide -- in situ toughening -- layered ceramics -- Nanoparticles -- silicon carbide; Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.16023
• Languages: English
• ISSNs: 0002-7820

Abstract

Abstract: In situ toughened B12 (C, Si, B)3 –SiC ceramics were successfully fabricated via the liquid silicon infiltration process. Two types of B12 (C, Si, B)3 phases, with high and low Si contents, respectively, and plate‐like SiC particles were formed by the reaction between B4 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‐B4 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 .