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Effect of Internal Current Flow During the Sintering of Zirconium Diboride by Field Assisted Sintering Technology
Author(s) -
Gonzalez–Julian Jesus,
Jähnert Kevin,
Speer Kerstin,
Liu Limeng,
Räthel Jan,
Knapp Michael,
Ehrenberg Helmut,
Bram Martin,
Guillon Olivier
Publication year - 2016
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.13931
Subject(s) - sintering , materials science , spark plasma sintering , zirconium diboride , graphite , microstructure , metallurgy , boron nitride , composite material , grain growth , ceramic , electrical resistivity and conductivity , zirconium , powder metallurgy , electrical engineering , engineering
Effect of electric current on sintering behavior and microstructure evolution of zirconium diboride (ZrB 2 ) was investigated using three different configurations of Field Assisted Sintering Technology/Spark Plasma Sintering. The current flow through the ZrB 2 compact was controlled by modifying the interface between the graphite punches and the electrical conductive powder. Boron nitride discs, graphite foils or direct contact with the graphite punches were the three different interfaces used in order to deflect, conduct or promote, respectively, the current during the sintering process of the electrically conductive ZrB 2 ceramics. The current flow during the sintering process triggered the elimination/reduction in B 2 O 3 , leading to faster diffusion rates at high temperatures and limiting the formation of B 4 C secondary phase. This allows to control the final density, grain size (from 19.6 to 43.2 μm) and secondary phase formation (from 5.95 to 11.61 vol%) as well as the electrical resistivity (from 7.7 to 9.4 μΩ·cm) of the specimens.