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Low‐Temperature Densification of Zirconium Diboride Ceramics by Reactive Hot Pressing
Author(s) -
Chamberlain Adam L.,
Fahrenholtz William G.,
Hilmas Gregory E.
Publication year - 2006
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.1551-2916.2006.01299.x
Subject(s) - zirconium diboride , materials science , hot pressing , zirconium carbide , boron carbide , zirconium , ceramic , silicon carbide , composite material , titanium diboride , vickers hardness test , crystallite , metallurgy , relative density , sintering , boron , microstructure , chemistry , organic chemistry
Zirconium diboride–silicon carbide ceramics with relative densities in excess of 95% were produced by reactive hot pressing (RHP) at temperatures as low as 1650°C. The ZrB 2 matrix was formed by reacting elemental zirconium and boron. Attrition milling of the starting powders produced nanosized (<100 nm) Zr particulates that reacted with B below 600°C. The reaction resulted in the formation of nanoscale ZrB 2 crystallites that could be densified more than 250°C below the temperatures required for conventional ZrB 2 powder. Because of the low‐temperature densification, the resulting ZrB 2 grain sizes were as small as 0.5±0.30 μm for specimens densified at 1650°C and 1.5±1.2 μm for specimens densified at 1800°C. Vickers hardness, elastic modulus, and flexure strength of fully dense materials produced by RHP were 27, 510, and 800 MPa, respectively.