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Journal of the Korean Ceramic Society 1997;34(6): 591. |
| 용융 Al의 치환반응에 의한 $Al_2O_3/Al$ 복합체의 제조 |
| 정두화, 김용진1, 배원태2 |
포항산업과학연구원 내화재료연구팀
1(주) 창원 기술연구소
2경상대학교 무기재료공학과 |
| Fabrication of $Al_2O_3/Al$ Composites by Replacement Reaction of Molten Metal Al |
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| ABSTRACT |
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Al2O3/Al composites were produced by displacement reaction method, which was carried out by immersing the sintered silica preform, which was prepared from fused silica powder, in molten aluminum. Because the molten aluminum did not penetrate into the silica preform with higher than 20% of porosity when the displacement reaction was accomplished at 100$0^{circ}C$ for 10 hours in air atmosphere, the optimum range of sintering temperature of silica preform was from 135$0^{circ}C$ to 140$0^{circ}C$. The microstructure of this Al2O3/Al composites showed three-dimentionally co-continuous alumina, which provides wear resistance and high stiffness, and aluminium which acts as a toughnening phase. The grain size of the alumina in composites did not change with the particle size of the silica preform. The exact shape of the preform was retained and a net-shaped composite was produced. The representative Al2O3/Al composite prepared in this study showed 3.30mg/㎤ of bulk density, 350-430 MPa of flexural strength, 7.0 MPa.m1/2 of fracture toughness, and good machinability. |
| Key words:
Melt infiltration, Aluminium, Fused silica preform, $Al_2O_3/Al$ composite |
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