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Vol.44, No.6, 446 ~ 451, 2006
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| Title |
| Special Edition : Symposium on Nano and Biomaterials ; Microstructure and Mechanical Properties of Fibrous HAp-(t-ZrO2)/Al2O3-(m-ZrO2) Composites Fabricated by Multi-Extrusion Process |
| 이치우 Chi Woo Lee , 윤민호 Min Ho Youn , 송호연 Ho Yeon Song , 이병택 Byong Taek Lee |
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| Abstract |
| Core-shell structured HAp-(t-ZrO2)/Al2O3-(m-ZrO2) composites were fabricated using a multi extrusion process. The shell of Al2O3-(m-ZrO2) phases was selected due to their excellent biocompatibility and mechanical properties and the core was designed with t-ZrO2 dispersed HAp matrix, In the 3rd passed sample, core/shell and fibrous microstructures having 4㎛ in diameter and 1㎛ in thickness were clearly observed. In the composite sintered at 1200℃, many pores were observed in both HAp-(t-ZrO2) core and Al2O3-(m-ZrO2) shell regions. However at 1500℃, the shell regions showed dense microstructure. The values of relative density, hardness, bending strength and fracture toughness in the sample sintered at 1500℃ were higher than those of 1200℃ and their maximum values were at 1500℃ about 95%, 967Hv, 278 MPa and 4.2 MPam(1/2), respectively. The fracture morphology was appeared with homogeneously rough surface due to the crack deflection and phase transformation of t-ZrO2 particles. |
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| Key Words |
| Hydroxyapatite, HAp-(t-ZrO2)/Al2O3-(m-ZrO2) composite, Fibrous microstructure, Multi-extrusion |
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