Lu2O3-SiO2계 소결조제를 포함하는 Silicon Nitride의 소결 특성 및 기계적 거동 |
이세훈, 조춘래, 박영조, 고재웅, 김해두 |
한국 기계연구원 부설 재료연구소 엔지니어링세라믹연구그룹 |
Densification and Mechanical Properties of Silicon Nitride Containing Lu2O3-SiO2 Additives |
Sea-Hoon Lee, Chun-Rae Jo, Young-Jo Park, Jae-Woong Ko, Hai-Doo Kim |
Engineering Ceramics Research Group, Korea Institute of Materials Science |
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ABSTRACT |
Gas pressure sintering (GPS) of reaction bonded silicon nitride (RBSN) was performed using $Lu_2O_3-SiO_2$ additive and the properties were compared with those of specimens prepared using high purity $Si_3N_4$ powder. The relative density of RBSN and compacted $Si_3N_4$ powder were 68.9 and 47.1%, and total linear shrinkage after sintering at $1900^{circ}C$ were 14.8 and 42.9%, respectively. High nitrogen partial pressure (5MPa) was required during sintering at $1900^{circ}C$ in order to prevent the decomposition of the nitride and to promote the formation of SiC. The relative density and 4-point bending strength of RBSN and $Si_3N_4$ powder compact were 97.7%, 954MPa and 98.2%, 792MPa, respectively, after sintering at $1900^{circ}C$. The sintered RBSN also showed high fracture toughness of 9.2MPam$^{1/2}$. |
Key words:
Additives, Densification, Gas pressure sintering, Silicon nitride, Strength |
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