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Low‐Temperature Glass Bonding for Development of Silicon Carbide/Zirconium Tungsten Oxide Porous Ceramics with Near Zero Thermal Expansion Coefficient
Author(s) -
Poowancum Anurat,
Matsumaru Koji,
Ishizaki Kozo
Publication year - 2011
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.1551-2916.2011.04520.x
Subject(s) - thermal expansion , materials science , negative thermal expansion , sintering , ceramic , borosilicate glass , composite material , thermal decomposition , zirconium , silicon carbide , porosity , tungsten , metallurgy , chemistry , organic chemistry
Near zero thermal expanding porous ceramics are useful in many applications in advanced manufacturing techniques, especially electronics engineering. Zirconium tungsten oxide (ZrW 2 O 8 ) has been expected to be an excellent negative thermal expansion material for reducing thermal expansivity of composites. However, at 777°C ZrW 2 O 8 decomposes to ZrO 2 and WO 3 , which have positive thermal expansion coefficient and limit applications of ZrW 2 O 8 . Therefore, a low temperature sintering technique is required to use ZrW 2 O 8 in zero thermal expanding composite. This work develops a low temperature glassy bonding agent to fabricate near zero thermal expanding SiC/ZrW 2 O 8 porous ceramics. The results show ZrW 2 O 8 reacts with alkali and alkaline earth oxides at lower temperatures than the decomposition temperature of ZrW 2 O 8 . Nevertheless, ZrW 2 O 8 is inert with Al 2 O 3 , B 2 O 3 , and SiO 2 . By using borosilicate glass (B 2 O 3 –SiO 2 ) as a bonding agent, SiC/ZrW 2 O 8 porous ceramics are sintered at temperatures lower than the decomposition temperature of ZrW 2 O 8 and have near zero thermal expansion coefficient (−0.2 × 10 −6 K −1 ). No reaction is found between the glassy bonding agent and ZrW 2 O 8 or SiC.