Al2O3-SiC 복합재료의 미세조직 및 기계적 물성에 미치는 SiC 원료분말의 크기 영향 |
채기웅 |
호서대학교 신소재공학전공 |
Effect of SiC Particle Size on the Microstructure and Mechanical Properties Of Al2O3-SiC Composite |
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ABSTRACT |
The effect of SiC particle size on the microstructures and mechanical properties of A1$_2$O$_3$-SiC composite was investigated. Two types of SiC powders having average particle sizes of 0.15 ${mu}{textrm}{m}$ and 3 ${mu}{textrm}{m}$ were used. The grain growth in the specimen containing 0.15 ${mu}{textrm}{m}$ SiC was effectively inhibited due to the fine SiC particles. However, after the formation of some abnormal grains, fast and exaggerated grain growth occurred which led to the microstructure of large grains with irregular shape. Fracture strength decreased due to the abnormal large grains. On the other hand, for specimen containing 3 ${mu}{textrm}{m}$ SiC showed normal grain growth behavior from initial sintering stage. Large SiC particles, however, effectively inhibited exaggerated grain growth after nucleation of a few abnormal grains. As a consequence, microstructure consisted of homogeneous elongated grains. In the A1$_2$O$_3$-2.5SiC(0.15 ${mu}{textrm}{m}$)-2.5SIC(3 ${mu}{textrm}{m}$) composite fabricated by mixing the two types of SiC powder, abnormal grain growth occurred. However, the good fracture strength was maintained regardless of microstructural changes in this specimen. |
Key words:
Abnormal grain growth, Particle size, Composite, Fracture strength |
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