Fabrication Of Porous Niobium Biomaterials Via Impregnation And Its Properties

Niobium, excellent bioactivity and biocompatibility and the lowest biological toxicity, in recent years has gradually become a research hotspot of biological scientists. However, the conventional metallic biomaterials implanted in the body have several inherent limitations such as, high density, relatively high modulus of elasticity and bad biological activity which weaken the implantation effect. How to design and manufacture porous niobium metallic biomaterials with both excellent bioactivity and biomechanical compatibility will be the research focus of scientists.In this paper the object was using the organic foam preparing the porosity porous niobium biological material by impregnation. First, using different types of organic polyurethane foam as a template to configured different concentrations of polyvinyl alcohol solution, prepare porous niobium green body with different impregnation amount, so as to obtain the best porosity porous niobium specimens. Second, using the medium frequency heating furnace sinter porous niobium green body by setting the sintering temperature, time, optimize the mechanical properties of porous niobium samples to get the best sintering parameters. Third, the porosity, compressive strength, elastic modulus, pore morphology, micro-organizational structure, section of the porous niobium sample and the contents and positions of oxygen and carbon were tested by hydrostatic, SEM and vertical microscope.The results show that:the amount of the impregnation of porous niobium sample is increased with the concentration of polyvinyl alcohol (PVA), at first the porosity of the porous niobium sample is reduced then increased; when the concentration of PVA is5%, we can get the best porosity at65.8%; the porous niobium has the three-dimensional connectivity of the organic foam pore structure morphology which is similar to cancellous bone,the pore size in the range of300-500μm, lots of micro-pore in the pore wall, the surface is very roughness;there are three stage of the compression stress-strain curve of porous niobium which has a stress flat; the elastic modulus gradually decreases with the porosity increased with the of the porous niobium sample; the max value of elastic modulus and compressive strength are0.815GPa and36.6MPa at the sintering temperature of2h; with the improvement of the sintering temperature, sintering neck diameterthe, mechanical properties were increased; the porous niobium’s fracture mode is brittle, fan-shaped fracture; carbon and oxygen impurity elements formed interstitial solid solution in niobium, enriched in the edge of the pore wall, which leads the niobium to brittleness.