Research On Microstructure And Mechanical Properties Of Biomedical Titanium Alloys

Due to their similar elastic modulus to bone, excellent biocompatibility and mechanical properties and corrosion resistance in biological environment, titanium alloys have been widely studied and widely used in clinics. According to exploitation status quo and existing flaws of titanium alloys for surgical implants, considering the design principles and melting technology, new titanium alloys Ti-Mo and Ti-Mo-Nb for surgical implants is designed and studied, and also their mechanical properties and microstructures are systematically studied in this thesis. The concrete contents and results are shown as the follows:According to characteristics of each kind of titanium alloy , the design principles and d theory of the alloy, Mo and Nb are selected as intensification elements, which possess excellent corrosion resistance and outstanding biocompatibility, at the same time, have few effects on plastic deformation during strengthening the matrix. Based on the effect of Mo and Nb on strength of the titanium alloy, and then the titanium alloys are confirmed as Ti-Mo alloys, and then a new kind of biomedical titanium alloys was prepared when element Nb was added to the Ti-Mo alloys.The effect of Mo on the microstructure and mechanical properties of Ti-Mo alloys have been systematically studied by means of Optical Microscope(OM), X-ray Diffraction(XRD), Transmission Electron Microscope (TEM).The mechanics behaviors for compression strength, the elastic modulus and Vickers hardness were studied, too. At the same time, the influence of Mo on Ti-Mo alloys'mechanics behavior and the fracture behavior were analysed.The results indicate that the size of Ti-Mo alloys'equi-axed grains was dramasticly decreased and needle exudation matters in crystal interior distributed unorderly were found and the alloy has excellent complex mechanics behavior when the content of Mo is 10 wt %. When Nb was added to Ti-10Mo alloy ,the influence of Nb on it related to microstructure and properties was studied, and the microstructure of Ti-10Mo-10Nb alloy is made up of equi-axed and dendriticβgrains, its yield strength is similar with that of Ti-10Mo alloy and plastic properties were improved greatly. A new biomedical alloy was prepared finally...