A Si 3N 4 composite containing needle-like TiN particles (7vol%) was fabricated. Needle-like TiN particles several micrometers long were synthesized using NH 3 nitridation of TiO 2 nanofiber, which was obtained using hydrothermal treatment. A mixed powder of α-Si 3N 4 and the needle-like TiN particles with additives was hot pressed at 24MPa and 1850°C for 1h in N 2 atmosphere. Mechanical properties of the composite were compared with those of a composite containing rounded TiN particles and a monolithic β-Si 3N 4 ceramic. The Si 3N 4 matrix of the composites containing TiN was mainly a-phase, suggesting that the α-β phase transformation of Si 3N 4 was inhibited by the presence of TiN. Although fracture strength of the composites was lower, fracture toughness was comparable to that of monolithic β-Si 3N 4 ceramics. Hardness of the composites was about 19GPa and was greater than that of the monolithic β-Si 3N 4 ceramic.
|ジャーナル||Journal of the European Ceramic Society|
|出版ステータス||Published - 2012 6|
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