The effect of different sintering temperature to the properties of cow bone hydroxyapatite

Abstract

Hydroxyapatite (HA) has been proved to be very compatible with the surrounding tissue of vertebrates since its chemical compositions similar to human bone and teeth. Natural HA has potential to be used as implant material. Main source of natural HA used are cow bones. Extraction of HA from cow bone is biologically safe and economic. In this study, effect of different sintering temperature to the properties of cow bone HA (CBHA) was carried out in two parts. First part is about characterization of raw materials. Temperature 800°C is chosen as calcination temperature. Fine CBHA is successfully produced via calcinations and milling process. From the result, particle sizedistribution for fine CBHA is 10.324μm. The phase obtained from XRD analysis is HA.Elemental analysis by XRF detects phosphorus (P) and calcium (Ca) with the Ca/P ratioof 1.67. Functional groups examined by FTIR detect hydroxyl (OH-), carbonate (CO3 2-) and phosphate (PO43-). SEM shows non uniform distribution of particle. In the secondpart, effects of different sintering temperature (1150°C, 1200°C, 1250°C, and 1300°C) to the properties of CBHA were studied. The XRD results for CBHA correspond with standard HA for all temperature. Sintering temperature is inversely proportional with XRD peaks intensities. Shrinkage analysis shows that the higher percentage of shrinkage value is 47.65 % recorded at 1300°C. Whereas, density and porosity testing show that the lowest percentage of porosity value is 4.52 % at 1300 °C and density reaches maximum value of 2.52 g/cm3 for specimen at 1250 °C and remains constant at 1300 °C. Mechanical properties observation through MOR testing shows that the highest value (35.14N/mm2) obtained at 1300°C. SEM analysis on the specimen sintered at 1300 °C shows uniform grain size at the range 2 – 4 μm, with minimum amount of pore. As a conclusion the sintering temperature affect the physical, microstructure, phase and mechanical properties of CBHA.