SiC와 TiC 입자를 함유하는 Al2O3 입자복합체의 균열저항거동과 기계적 성질 |
나상웅, 이재형 |
영남대학교 재료금속공학부 |
R-Curve Behavior and Mechanical Properties of Al2O3 Composites Containing SiC and TiC Particles |
Sang-Woong Na, Jae-Hyung Lee |
School of Metallurgical and Materials Engineering, Yeungnam University |
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ABSTRACT |
Particulate composites of $Al_2O_3$/TiC/SiC, $Al_2O_3$/TiC and $Al_2O_3$/SiC have been fabricated by hot pressing and their R-curve behaviors and mechanical properties were investigated. $Al_2O_3$ containing 30 vol% TiC particles showed higher toughness by 8% than that for monolithic alumina and its fracture strength was increased significantly by approximately 30%. On the other hand, the addition of 30 vol% SiC of $3{mu}m$ in $Al_2O_3$ decreased the fracture strength slightly but induced a rising R-curve behavior owing to the strong crack bridging of SiC particles. In case of $Al_2O_3$/TiC/SiC, arising R-curve behavior was also observed and the fracture toughness reached 6.6 MPa${cdot}sqrt{m}$ at the crack length of $1000{mu}m$, which was lower than that of $Al_2O_3$/SiC, however, while the fracture strength was higher by about 20%. The fracture toughness seemed to be decreased as smaller TiC particles roughened the SiC interface and pullout of the SiC particles for crack bridging became less active. |
Key words:
Particulate composites, R-curve behavior, Fracture toughness, Particle bridging, Crack bridging |
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