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In Situ Synthesis and Microstructures of Tungsten Carbide‐Nanoparticle‐Reinforced Silicon Nitride‐Matrix Composites
Author(s) -
Iizuka Tateoki,
Kita Hideki,
Hyuga Hideki,
Hirai Takene,
Osumi Kazuo
Publication year - 2004
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/j.1551-2916.2004.00337.x
Subject(s) - sintering , materials science , tungsten , composite material , composite number , tungsten carbide , nanoparticle , flexural strength , microstructure , carbon fibers , grain boundary , silicon carbide , silicon nitride , metallurgy , nanotechnology , layer (electronics)
A W 2 C‐nanoparticle‐reinforced Si 3 N 4 ‐matrix composite was fabricated by sintering porous Si 3 N 4 that had been infiltrated with a tungsten solution. During the sintering procedure, nanometer‐sized W 2 C particles grew in situ from the reaction between the tungsten and carbon sources considered to originate mainly from residual binder. The W 2 C particles resided in the grain‐boundary junctions of the Si 3 N 4 , had an average diameter of ∼60 nm, and were polyhedral in shape. Because the residual carbon, which normally would obstruct sintering, reacted with the tungsten to form W 2 C particles in the composite, the sinterability of the Si 3 N 4 was improved, and a W 2 C–Si 3 N 4 composite with almost full density was obtained. The flexural strength of the W 2 C–Si 3 N 4 composite was 1212 MPa, ∼34% higher than that of standard sintered Si 3 N 4 .