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Effects of aggregate/matrix‐phase ratio on the in‐situ synthesis of SiC whiskers and properties of reaction‐bonded SiC
Author(s) -
Li Yage,
Lao Xinbin,
Wang Tao,
Liu Jianmin,
Jiang Feng,
Feng Guo,
Jiang Weihui,
Tang Huidong
Publication year - 2020
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.13573
Subject(s) - materials science , whiskers , composite material , scanning electron microscope , phase (matter) , graphite , transmission electron microscopy , microstructure , nanotechnology , chemistry , organic chemistry
Reaction‐bonded silicon carbide (RBSC) materials were synthesized by a carbon‐buried firing method, using α‐SiC powders with different sizes as aggregates, while silicon and graphite powders as matrix‐phase materials for in‐situ synthesis of β‐SiC. The effect of the mass ratio of α‐SiC aggregate to β‐SiC matrix‐phase on the in‐situ synthesis of β‐SiC whiskers was investigated and the optimum mass ratio was determined according to the properties of RBSC materials. The phase compositions, microstructure, and properties of the RBSC materials were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscope (TEM), respectively. The results showed that the decreasing aggregate/matrix‐phase ratio could increase the yield and aspect ratio of β‐SiC whiskers by improving the amount of pores and SiO 2 content. The β‐SiC whiskers with stacking faults grew along [111] direction. The in‐situ formed β‐SiC whiskers and SiO 2 in the matrix‐phase enhanced the hot modulus of rupture (HMOR) of the RBSC materials, and the sample with the aggregate/matrix‐phase ratio of 70:30 showed the highest cold modulus of rupture (CMOR) of 53.3 MPa, high HMOR of 43.3 MPa, and medium water absorption of 13.8%.