Microstructure And Mechanical Propertise And Corrosion Behaviour Of TiMoSn Biomedical Alloys

The microstructrue, phase composition , mechanical properties, shape memory effect and corrosion behavior of TiMoSn alloys were investigated by means of optical microscope, TEM, XRD analysis, EDS, tensil test, bending test, electrochemical measurement and XPS.The phase of as-cast TiMoSn alloys are composed ofα″andβphase. With the increasing of Sn content, the diffraction peaks nearly have changed, so we can say content of Sn have no influence on the alloys phase composition. The phase of TiMoSn alloys as-rolled is whollyβphase. The phase composition of solution treated TiMoSn alloys are composed ofα″andβphase. With the content of Sn increasing, the diffraction peaks ofα″become weak.The results of TEM observation are that martensite was not observed in TiMoSn alloy. There are dencity dislocation in Ti-6Mo-6Sn alloy. Strap and lines dislocation exist in Ti-6Mo-5Sn and Ti-6Mo-6Sn alloys.The elastic modulus of TiMoSn alloy increased with the content of Sn, and the ultra tensile stress and yield stress have not clearly regular. We obtained the best combination of mechanical properties in alloys after aging at 1173K, the alloy aging at 1072K and 1273K have nearly the same properties. Ti-6Mo-6Sn aging at 1173K has the best combination of mechanical properties in all those alloys, yield stress 864MPa, ultra tensile stress 880MPa, elastic module 74GPa, elongation 12.7%.The fracture mode of as-rolled and solution treated TiMoSn alloys is ductile fracture with the appearance of necking down, and the main characterisitic of broken cross-section is dimple.The results show that TiMoSn do not have a good shape memory effect. The recovery ratio decrease with the increasing of pre-strain. The recovery ratio is less 50% when the pre-strain is more than 4%.The electrochemical testing indicates that the TiMoSn alloys have excellent anti-corrosion properties. OCP curves of TiMoSn alloys show that the passive film on the alloy surface is very stable. The anodic polarization curves proved that the TiMoSn alloys have excellent anti-corrosion properties. The pH values of...