Toru Nonami

Study on Diopside Whiskers Precipitation Type Hydroxyapatite

A biomedical material for use as artificial bone and dental root is provided which takes the form of a sintered composite body comprising a Hydroxyapatite(HAP) and diopside whisker. The mixed powder of HAP and diopside was heated to make this composite material. The sintering of HAP and the precipitation of diopside whisker were examined, to find a method of making them occur simultaneously. Also, diopside was added to HAP and sintering at 1200°C for 2hr. was done. As a result of these investigations, diopside whisker of aspect ratio 101˜15 was formed. Moreover the intermediate layer of CaO-SiO 2 -P 2 O 5 -Mg O system was generated at the interface of HAP and whisker. The bending strength of this sintered body was 300MPa and fracture toughness was 3.2MPa ·m 1/2 . These values were higher by about 2times or 3times than those of matrix HAP respectively. The increase in bending strength was attributed to an increase in fracture toughness, caused by an increase in fracture surface energy.