Original Paper(Vol.60 No.3 pp.198-201)

Anelastic Behavior of Hydroxyapatite Ceramic

Masakuni OZAWA, Masayuki ICHIYANAGI and Suguru SUZIKI

Abstract:The relationship between anelastic property and chemical species (F, OH) in calcium-containing apatite structure was investigated by the dynamic elastic technique. The internal friction and dynamic modulus of two apatite-type ceramics of hydroxylapatite (HAP) and fluoroapatite (FAP) were measured by using a forced torsion apparatus. The internal friction (IF) amplitude of about 0.01 was observed for HAP in the temperature range of |50 to 100. However, no IF appeared for FAP, in which hydroxyl-group was replaced by fluorine. The modulus of HAP showed the decrease corresponding to the IF amplitude. The author discussed that the dynamic relaxation of hydroxyl-group was evolved with the anelastic phenomenon of the apatite-structured material.

Key Words:Hyodroxyapatite, Internal friction, Fluoroapatite, Phase transformation, Anelastic relaxation