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High fracture toughness of HfC through nano‐scale templating and novel sintering aids
Author(s) -
Hao Wei,
Ni Na,
Guo Fangwei,
Cao Fangcheng,
Jiang Juan,
Zhao Xiaofeng,
Xiao Ping
Publication year - 2019
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.15956
Subject(s) - materials science , sintering , fracture toughness , ceramic , microstructure , composite material , toughness , composite number , carbide , carbon fibers , carbonization , nano , nanoscopic scale , nanotechnology , scanning electron microscope
An approach to improve the sintering ability and the fracture toughness of hafnium carbide (HfC) ceramic by designing a unique composite structure is reported. The uniform and ultra‐fine HfC nanoparticles (~300 nm) are synthesized at 1450°C by vacuum carbonization reaction with the glucose‐derived hydrothermal precursor as a carbon source and template. HfC ceramic sintered with a SiCN sintering aid of 15 vol. % possesses a beneficial three‐dimensional network microstructure composed of inter‐penetrating phases of carbon, SiC and HfC with varied stoichiometry at multi‐length scales. The obtained HfC exhibits a higher fracture toughness of 5.5 MPa m 1/2 , which can be attributed to the unique composite structure able to promote stress releases in the crack tip and enhance the resistance to crack propagation.