TY - JOUR
T1 - Microstructure and mechanical properties of Si3N4f/BN/Si3N4 composites by joint processes of PIP and CVI
AU - Zhou, Jie
AU - Ye, Fang
AU - Cheng, Laifei
AU - Wei, Yucong
AU - Li, Mingxing
AU - Meng, Nan
AU - Cui, Xuefeng
N1 - Publisher Copyright:
© 2022
PY - 2022/6/2
Y1 - 2022/6/2
N2 - The three-dimensional silicon nitride (Si3N4) fiber-reinforced silicon nitride matrix (3D Si3N4f/BN/Si3N4) composites with boron nitride (BN) interphase were fabricated by joint processes of precursor infiltration and pyrolysis (PIP) and chemical vapor infiltration (CVI). The fracture morphologies and mechanical properties of Si3N4f/BN/Si3N4 composites with different PIP and CVI Si3N4 matrix content were studied. The composites with 50 vol% PIP matrix and 50 vol.% CVI matrix show the most optimal mechanical properties, especially the highest fracture toughness reported so far, whose flexural strength and fracture toughness are 198 ± 15 MPa and 7.5 ± 0.9 MPa·m1/2, respectively. Meanwhile, the fracture characteristics were analyzed, and the strengthening and toughening mechanisms dominated by the fibers and high/low modulus matrices, corresponding to CVI/PIP matrices respectively, were also discussed. It is concluded that the multi-step fiber pull-out is conducive to improving both the strength and toughness, where the strengthening and toughening mechanisms include: (Ⅰ) relieving stress and resisting crack propagation by high/low modulus matrices; (Ⅱ) strengthening by short debonded fibers and toughening by long debonded fibers.
AB - The three-dimensional silicon nitride (Si3N4) fiber-reinforced silicon nitride matrix (3D Si3N4f/BN/Si3N4) composites with boron nitride (BN) interphase were fabricated by joint processes of precursor infiltration and pyrolysis (PIP) and chemical vapor infiltration (CVI). The fracture morphologies and mechanical properties of Si3N4f/BN/Si3N4 composites with different PIP and CVI Si3N4 matrix content were studied. The composites with 50 vol% PIP matrix and 50 vol.% CVI matrix show the most optimal mechanical properties, especially the highest fracture toughness reported so far, whose flexural strength and fracture toughness are 198 ± 15 MPa and 7.5 ± 0.9 MPa·m1/2, respectively. Meanwhile, the fracture characteristics were analyzed, and the strengthening and toughening mechanisms dominated by the fibers and high/low modulus matrices, corresponding to CVI/PIP matrices respectively, were also discussed. It is concluded that the multi-step fiber pull-out is conducive to improving both the strength and toughness, where the strengthening and toughening mechanisms include: (Ⅰ) relieving stress and resisting crack propagation by high/low modulus matrices; (Ⅱ) strengthening by short debonded fibers and toughening by long debonded fibers.
KW - CVI
KW - High/low modulus matrices
KW - Mechanical properties
KW - PIP
KW - SiN/BN/SiN composites
UR - http://www.scopus.com/inward/record.url?scp=85129053983&partnerID=8YFLogxK
U2 - 10.1016/j.msea.2022.142988
DO - 10.1016/j.msea.2022.142988
M3 - 文章
AN - SCOPUS:85129053983
SN - 0921-5093
VL - 844
JO - Materials Science and Engineering: A
JF - Materials Science and Engineering: A
M1 - 142988
ER -