Microstructure of Directionally Modified SiC Whisker C/SiC Composites Prepared With LA-CVI Technique

Jing Wang, Yongsheng Liu, Chenhao Wang, Yunhai Zhang, He Li, Laifei Cheng

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

Poor thermal conductivity of continuous fiber-reinforced silicon carbide (SiC) ceramic matrix (C/SiC) composites has become a huge obstacle to be widely used as thermal protection systems and hot structures for hypersonic vehicles. Herein, a high thermal conductivity of C/SiC composites modified with SiC whiskers (SiCw) was constructed by laser-assisted chemical vapor infiltration (LA-CVI). The inserted SiCw into the C/SiC composites were served as the second phase, yielding a unique three-dimensional network structure. Density, mechanical properties, and thermal conductivity of the prepared composites were systematically investigated. Results show that the bending strength (600 MPa) of the LA-CVI-C/SiC-SiCw composites is 27.6% higher than that of CVI-C/SiC composites (470 MPa). With the fiber debonded, fractured, and pulled out hierarchically, the failure crack propagated express Step-extension. Besides, the thermal conductivity (45.13 Wm−1K−1) of LA-CVI-C/SiC-SiCw composites is a factor 4 to 5 higher than that of CVI-C/SiC composites (10 Wm−1K−1). This work provides not only a facile method to construct high thermal conductivity C/SiC composites but an effective way to overcome the difficulties of improving the thermal conductivity of ceramic matrix composites (CMCs).

Original languageEnglish
Article number155
JournalFrontiers in Materials
Volume7
DOIs
StatePublished - 16 Jun 2020

Keywords

  • density
  • LA-CVI process
  • mechanical properties
  • microstructures
  • SiCw reinforced C/SiC composites
  • thermal conductivity

Fingerprint

Dive into the research topics of 'Microstructure of Directionally Modified SiC Whisker C/SiC Composites Prepared With LA-CVI Technique'. Together they form a unique fingerprint.

Cite this