| Based on the d-electron alloy design theory (DV-X molecular orbital method) and Mo equivalent designing theory for titanium alloys, three beta type titanium alloys Ti-24Nb-5.2Zr-1.8Sn,Ti-24Nb-4.2Zr-0.8Sn,Ti-24Nb-4Zr (at.%) were designed in the experiment. The ingots were prepared by high vacuum arc smelting furnace, then they were hot-forged and homogenizing treated, solution-treated and cool-rolled and finally annealed at different temperatures. Phase transformation characters were analysed by using X-ray diffraction (XRD) and optical microscope. The tensile property was tested by static stretching, hardness'tests used vickers hardness tester, and anodic polarization curves were tested by electrochemical workstation.The results show that the microstructure of the alloys is stable phaseβat room temperature. Hot-forged alloys were heated at 850℃for 1 hour and water quenched, then they could be cool rolled with reduction of more than 90% without any cracks. Small amount of highly dispersive ? phase formated during aging after solution treatment, which could lead to corresponding changes of the tensile strength, yield strength, Young'moludus, vickers hardness, plasticity and toughness. But due to the amout of ? phase is very small and highly dispersive, the X-ray diffraction (XRD) could't find it, nor the transformation temperature ofβ/? cannot be measured by differential thermal analyzer(DTA) . Plasticity and toughness decrease during aging,but the match of strength and toughness is still good.When testing the vickers hardness, we find hardness values are dierent in different directions, this is because textures of alloys cause anisotropy of alloys'properties.The experiment also uses anodic polarization curves to analyse the alloys'corossion resistanse, finding out that alloys'corossion resistanse under different heat treatments is slightly different. Corossion resistanse of all the three alloys is good.
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