Preparation And Compressive Properties Of Titanium Foam

As a new kind of structure-function combined material Titanium foam, possesses many excellent properties such as high porosity, good mechanical performance, corrosion resistance, permeability and biocompatibility. On the one hand, Young’s modulus of titanium is reduced by the introduction of the pore structure. Moreover, Young’s modulus of titanium foam could be tailored to meet biomedical implants requirements. On the other hand, bone ingrowth is induced by pore structure achieving ideal biological-combination effects. Therefore, titanium foam is a promising biological implant material.To meet the requirements of bio-implant material, titanium foam was produced by space-holder method of powder metallurgy method. Titanium powders and TiH2powders were selected as raw powders. Ammonium bicarbonate was chosen as the pore-forming agent. The control mechanism and optimal process of pore structure were investigated. The porosity, pore distribution and compressive performance of titanium foam, which were produced with sintering temperature at850～1100℃, sintering time of1～3h, pore-forming agent content of40%～70%and particle size of pore-forming agent ranging from20to60mesh, were studied in detail. The porosity of titanium foam, which was produced by adding different content of pore-forming agent, ranges from44%to77%. Titanium foam was successfully prepared whose macroporous size varies from200to500μm and keyhole size was in micrometer scale. The results showed that the compressive yield strength and young’s modulus of titanium foam increased as sintering temperature and sintering time increased; with increased pore-forming agent content, foam titanium compressive yield strength and young’s modulus decrease. The compressive properties of titanium foam increased firstly and then decreased with decreasing pore size.Titanium foam was prepared with complicate pore structure, which was composed of three-dimensional transfixion and double-peak of cell wall were rich in several microns microporous so that the formation of surface bone-like apatite layer manifests bone induction to promote growth and connection of human bone. Titanium foam could meet needs of human bone tissues on compressive strength and young’s modulus.