中文摘要：

研究了低弹性模量β-Ti合金[MoTi14]Zr1（Ti78．2Mo11．2Zr10．6）和[SnTi14]Mo1（Ti75．7MO10．9Sn13．4）中第二相析出对弹性模量和力学性能的影响及其拉伸过程中合金组成相的变化．利用Cu模吸铸快冷技术制备了直径6mm的合金棒，并采用XRD和TEM分析合金拉伸前后的相析出行为及组织．结果表明，在卢基体上只有少量0：“的析出使得[SnTi14]MO1合金具有较低的弹性模量（70GPa），而ω相的存在使得[MoTi14]Zr1合金的弹性模量略高（80GPa）；且[SnTi14]Mo1合金中较细的薄片状卢孪晶组织使得合金具有优良的力学性能．在拉伸过程中，lMoTil4IZrl合金中应力诱发的马氏体含量增加，而在[SnTi14]Mo1合金中卢基体晶粒易于发生扭转，从而合金塑性提高．

英文摘要：

The influences of second phase precipitations of low Young＇s modulus （E） β-Ti al- loys [MoTi14]Zrl （Ti78.2Mo11.2Zr10.6） and [SnTi14]Mo1（Ti75.TMo10.9Sn13.4） on mechanical properties as well as the variation of phase constitutions of alloys during tensile test were investigated. Alloy rods with 6 mm diameter were prepared by copper-mould suction-cast method. Phase precipitations and microstructures of alloys before and after tension were analyzed by XRD and TEM techniques. The experimental results showed that only a minor amount of ~＂ martensite precipitated onβ matrix makes the suction-cast [SnTi14]M01 alloy possess lower E with a value of 70 GPa, while w precipitation increases the E （80 GPa） of [MoTi14]Zrl alloy. It is due to the thinner β plate twins that makes [SnTi14]M01 alloy have better mechanical properties. During tensile testing, the amount of a＇＇ martensite induced by stress increases in [MoTi14]Zr1 alloy while β grains in [SnTi14]Mo1 alloy are easier to be rotated for deformation, which favors to enhance the ductility of alloys.