| 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 |
| Authors |
이치우(Chi Woo Lee); 윤민호(Min Ho Youn); 송호연(Ho Yeon Song); 이병택(Byong Taek Lee) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
Hydroxyapatite; HAp-(t-ZrO2)/Al2O3-(m-ZrO2) composite; Fibrous microstructure; Multi-extrusion |
| 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. |