Indexed by:期刊论文

Date of Publication:2017-07-01

Journal:CERAMICS INTERNATIONAL

Included Journals:SCIE、EI、Scopus

Volume:43

Issue:10

Page Number:7454-7460

ISSN No.:0272-8842

Key Words:UHTCs; sZrB(2)-based composite; Fiber-reinforced composite; Carbon nanotubes; Fracture properties; Toughening mechanism

Abstract:Multi-walled carbon nanotubes (MWCNTs) were used to optimize the microstructure and improve the fracture properties of hot-pressed carbon fiber-reinforced ZrB2-based ultra-high temperature ceramic composites. Microstructure analysis indicated that the introduction of MWCNTs effectively reduced the carbon fiber degradation and prevented fiber-matrix interfacial reaction during processing. Due to the presence of MWCNTs, the matrix contained fine ZrB2 grains and in-situ formed nano-sized SiC/ZrC grains. The fracture properties were evaluated using the single edge-notched beam (SENB) test. The fracture toughness and work of fracture of the Cf/ZrB2-based composite with MWCNTs were 7.0 +/- 0.4 MPa m(1/2) and 379 +/- 34 J/m(2), respectively, representing increases of 59% and 87% compared to those without MWCNTs. The excellent fracture properties are attributed to the moderate interfacial bonding between the fibers and matrix, which favour the toughening mechanisms, such as fiber bridging, fiber pull-out and crack deflection at interfaces.