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Architectural design and cryogenic synthesis of Si 3 N 4 @(TiN–Si 3 N 4 ) for high conductivity
Author(s) -
Yang Mei,
Lv Mingli,
Wang Qi,
Zhu Hongmin
Publication year - 2018
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.15165
Subject(s) - tin , materials science , electrical resistivity and conductivity , spark plasma sintering , electrical conductor , conductivity , amorphous solid , relative density , sintering , analytical chemistry (journal) , chemical engineering , composite material , metallurgy , crystallography , chemistry , chromatography , electrical engineering , engineering
Si 3 N 4 @(TiN–Si 3 N 4 ) composites with heteroshelled structure were designed for enhanced conductivity and successfully synthesized through the simultaneous reduction and in‐situ cocoating process in liquid ammonia at around −40°C. The heteroshells were composed of nanosized TiN and Si 3 N 4 particles, which were amorphous with the size ranging from 10 to 40 nm. Using spark plasma sintering, dense bulk composite with >98.1% relative density of theoretical value were obtained and their electrical conductivity were increased to an adequate value (6.62 × 10 2 S·cm −1 ) for electrical discharge machining by compositing 15 vol% TiN to Si 3 N 4 , which is superior to the previous reports. The excellent electric performance could be attributed to the heteroshelled structure which guarantees the conductive network can be formed and kept with minimal TiN content. The nanosized Si 3 N 4 powders in the shells reduce the content of conductive powders and limit the growth of TiN particles.