Research On Preparation And Properties Of HAP/Ni₃ Al Composite Biomaterials

Hydroxyapatite bioceramic is a good type of biomedical material that is used to restore and replace the hard tissue of human bodies. It's biocompatible can form a bond with the neighboring bone. But hydroxyapatite isn't an ideal bearing planting, for it's bad mechanics properties. Therefore, it is necessary to carry out more research on it for giving its advantage of biological characteristics.In this paper, HAP/Ni3Al composite biomaterial has been prepared, and the preparation to the raw materials powder and prosperities of these materials, sintering craft of composite biomaterials and studies of the microstructure have carried on deeper experiment research and theory discussion, in order to obtain the experimental and theoretical foundation next.First, in this paper, with Ca(NO3)2 . 4H2O and (NH4) 2HPO4 as raw materials and NH3. H2O as regulating pharmaceutical of pHs, nanometer grains of HAP powder have prepared in precipitating method. HAP powder with grain diameter under 100 nm, average diameter 60-70 nm and bar shape can be obtained. TEM, IR, XRD and optics microscope were carried out to characterize phases and microstructure of specimen. Ni3Al powder was produced in this study by using Ni and Al powder. X-ray diffraction and optics microscope were used to characterize the structure, crystallite size and components.Second, Based on powders of HAP and Ni3Al, HAP/Ni3Al composite biomaterials were sintered by different kinds of materials. Mechanical properties of HAP/Ni3Al composite biomaterials were measured. To evaluate the biological properties, the muscular implant test in white rats and methyl benzoate test were carried out. The composition and microstructure of these materials were revealed by the means of testing methods of XRD, AFM, optics microscope, etc. The author introduce a suit of enhance method of preparing a compound biomaterial based hydroxyapatite, which can meet the demand of bearing planting. It was found that the crystal structure of HAP was not changed by the composite making process, thus the bioactivity of the composite biomaterials was not degraded either. Results of mechanical properties of HAP/Ni3Al composite biomaterials show that the mechanical properties of HAP/Ni3Al composite biomaterials had a good improvement after the composite process was carried out. The toughening mechanism of Ni3Al reinforced HAP composite materials was grand of Ni3Al-induced crack deflection toughing and micro-crack toughing. The study showed composite materials had good mechanical properties, chemical stability, and biocompatibility. The composites were new composite biomaterials with good prospects.Finally, HAP/Ni3Al composite biomaterials were prepared with HAP and Ni3Alpowders by novel gelcasting process. The mechanical properties of the biomaterials were investigated. The feasibility of preparing composite biomaterials by gelcasting process was studied laying the helpful theory and practice foundation for the further experiment.