Preparation And Property Of Short Carbon Fiber Reinforced Hydroxyapatite Bio-composite

In this paper, oxidation treated short carbon fiber (Cf) was used to improve the mechanical properties of hydroxyapatite (HA). The HA/Cf bio-composite powder was prepared by in-suit processing, through vacuum hot-press sintering the HA/Cf bio-composite block was prepared and the physical, mechanical properties were tested, the fracture surface morphologies of bio-composite were analyzed using SEM.The powder of pure HA was synthesized by sol-gel processing. After sintering without press at different temperatures, the phase structure of the powder was analyzed using XRD and the grain size was calculated using Scherre formula. Result shows that the degree of crystallinity of HA raised, the lines in the XRD patterns become strong and these refection planes agree well with the JCPDS files, this means the purity of HA was higher. The grain size of HA grow up to about 50 nm which calculated by Scherre formula.After ultrasonic dispersion, in order to improve the integration of Cf and HA, the Cf oxidation treated, the surface of Cf was analyzed using FTIR and SEM. Result dictates that after oxidation treated the Cf surface become course and the carbon fiber surface with concentrated hydrochloric acid treated were badly eroded, and the mechanical properties were lower. After treated there a lot of carboxyl and hydroxide appears on Cf surface.The HA/Cf bio-composite powder was prepared by in-suit processing, and some factors such as temperature and pressure were considered. By analyzing the XRD atlas, the proper sintering technical parameters are:vacuum, the sintering temperature 1473 K, the pressure 30 Mpa, the preservation time 10 min.The physical and mechanical properties of HA/Cf bio-composite samples were tested using electronic universal testing machine, the fracture surface morphologies of bio-composite were analyzed using SEM. Result illustrates that the resistivity of bio-composite is higher and surpasses 3.33×106Ω·m, like dielectric. When the mass fraction of carbon fiber (treated) got 3%, the relativity density, bending modulus, bending strength and fracture toughness reach the maximum values of 99.75%,36 GPa,130 MPa and 1.82 MPa-m1/2, among them bending modulus and bending strength surpass the common level of nature bone. The treated carbon fiber enforced bio-composite’s bending modulus, bending strength and fracture toughness are always higher than the untreated, respectively surpass 30%、25% and 17%. SEM fracture surface morphologies of HA/Cf shows Cf can be uniformly dispersed in the HA matrix when the mass fraction less than 6%, while when the mass fraction over 6%, partial aggregation appears, mechanical properties falls.