MECHANICAL PROPERTIES OF HYDROXYAPATITES SINTERED BY SPARK PLASMA SINTERING

摘要

Hydroxyapatite (HA) is superior in biocompatibility and bioactivity, as biomaterials. In this study, mechanical properties, three-point bending strength and Young's modulus of HA compacts sintered by Spark Plasma Sintering (SPS) were investigated. The structural changes in HA compacts were analyzed with scanning electron microscope (SEM) and X-ray diffraction (XRD). Six types of HA powder HAP-100, HAP-200, HAP-300, HAP-400, Spherical HAP and Spherical HAP-100 were manufactured by Taihei Chemical Industrial Co., Ltd. HAP-100 has an irregular grain with an average particle size(APS) of 38μm. HAP-200 has an irregular grain with an APS of 10 μm. HAP-300 and HAP-400 has a plate-like grain of an APS of 17 μm. Spherical HAP is a spherical particle of the average diameter of 19 μm. Spherical HAP-100 is a spherical particle of the average diameter of 40μm. HA were sintered at temperature of 1073, 1173, and 1273 K and at pressure of 22, 44 and 66 MPa. HAP-100 compact had the highest three-point bending strength and compressive strength, 111 MPa and 700 MPa respectively. HAP-300 compact had the highest Young's modulus, 103 GPa and 13 MPa m{sup}(1/2) respectively. Three-point bending strength, compressive strength, Young's modulus of HA sintered compacts decrease about exponentially with their porosity increase.