질화규소 세라믹스의 기계적 특성에 Y₃Al_(5)O_(12) 미치는 의 영향

Abstract

In the present work, silicon nitride was fabricated with Y₃Al_(5)O_(12) as sintering additive and its mechanical properties were investigated. Silicon nitride with 3, 5, 7wt% of Y₃Al_(5)O_(12) was prepared and sintered by a Hot Pressing (HP) technique at 1750, 1800℃ for 2 hours. The Process was fulfilled under different process pressures of 30, 45MPa respectively. Mechanical properties (density, strength, hardness, fracture toughness) were investigated as a function of Y₃Al_(5)O_(12) contents in Si₃N₄. Si₃N₄ -Y₃Al_(5)O_(12) ceramics showed similar mechanical properties compared with Si₃N₄-Y₂O₃-Al₂O₃ ceramics. But its high temperature strength was higher than Si₃N₄-Y₂O₃-Al₂O₃ ceramics considerably.