Effect of carbonate contents on the thermal stability and mechanical properties of carbonated apatite artificial bone substitute

• Main Authors: Thang, Le Hong, Bang, L. T., Long, B. D., Son, Nguyen Anh, Ramesh, S.
• Format: Article
• Published: Springer Verlag (Germany) 2023
• Subjects: TJ Mechanical engineering and machinery
• Online Access: http://eprints.um.edu.my/39492/
• Institution: Universiti Malaya

Carbonated apatite is the inorganic component of natural bone while the carbonate ion in the structure influences biological activities and osteoconductivity. However, thermal stability of carbonate apatite is a major importance since thermal stability of carbonate apatite is a function of carbonate content presented in the structure and heat treatment atmosphere. This research work investigates the effects of different carbonate contents on carbonate substitution, thermal stability, physical and mechanical properties of carbonate apatite synthesized by a precipitation method. The results indicated that the carbonate content influenced the properties of carbonated apatite powders. High carbonate substitution (10-11 wt.%) promoted the decomposition of carbonated apatite after heat treatment at 900 degrees C while a low amount of carbonate substitution (approx. 2 wt.%) resulted in the relocation of carbonate group from phosphate site to hydroxyl site without decomposition. It also demonstrated that a high carbonate amount resulted in a superior mechanical performance. Dense carbonated apatite with high carbonate content has achieved a relative density of 97% and a maximum fracture toughness of 1.4 MPa center dot m(1/2). In the contrary, low carbonate content resulted in a compact with high porosity of about 40% and a low toughness value of 0.35 MPa center dot m(1/2) when treatment at 900 degrees C.