低弹bcc结构Ti-Mo-Nb-Zr固溶体合金的“团簇+连接原子”模型及其成分设计

来源期刊：金属学报2010年第9期

论文作者：马仁涛 郝传璞 王清 任明法 王英敏 董闯

文章页码：1034 - 1040

关键词：Ti-Mo-Nb-Zr合金； β-Ti固溶体； “团簇+连接原子”结构模型； 成分设计； 低弹性模量

Key words：Ti-Mo-Nb-Zr alloy； β-Ti solid solution； cluster-plus-glue-atom model； composition design； low Young’s modulus

摘    要：利用"团簇+连接原子"结构模型研究了典型低弹bcc β-Ti固溶体合金的成分特征.对现有低弹β-Ti固溶体合金的成分分析表明它们均满足团簇式[CN14团簇](连接原子)_x.根据该式,设计了Ti-Mo-Nb-Zr系列合金[MoTi₁₄]Ti(质量分数表达时为Ti-11.8Mo),[MoTi₁₄]Nb(Ti-11.2Mo-10.8Nb),[MoTi₁₄]Nb₂(Ti-10.1Mo-19.5Nb)和[Mo(Ti₁₃Zr)]Nb₂(Ti-9.2Zr-9.6Mo-18.7Nb),并采用Cu模吸铸快冷技术制备直径为3和6 mm的合金棒.结果表明,吸铸制备的合金均为bcc结构;当连接原子由Ti变成更低弹的Nb时,合金弹性模量降低;低弹Zr替代Ti进一步降低了合金的弹性模量,[Mo(Ti₁₃Zr)]Nb₂合金的弹性模量E=72 GPa.铸态样品经过固溶和水淬处理后弹性模量降低.

Abstract: The composition characteristics of typical bcc β-Ti solid solution alloys with low Young’s modulus were analyzed by using the cluster-plus-glue-atom model,in which an alloy structure is dissociated into a cluster part and a glue atom part,i.e.isolated clusters are linked with glue atoms.The cluster here is the nearest neighbor coordination polyhedron with a coordination number of 14 (CN14).It is confirmed that β-Ti solid solution alloys with low Young’s moduli satisfy a universal cluster formula [CN14 cluster](glue atom)_x given by this model.Alloys,described by cluster formulas [MoTi₁₄]Ti,[MoTi₁₄]Nb,[MoTi₁₄]Nb₂ and [Mo(Ti₁₃Zr)]Nb₂,Ti-11.8Mo (mass fraction,%), Ti-11.2Mo-10.8Nb,Ti-10.1Mo-19.5Nb and Ti-9.2Zr-9.6Mo-18.7Nb were designed and the alloy rods with diameters of 3 and 6 mm were prepared by copper-mould suction-cast method,respectively. These suction-cast alloys possess monolithic bcc β-Ti structure.The introduction of low-modulus Nb as glue atoms weakens the cluster linking and decreases the Young’s modulus.Further substitutions with low-modulus Zr reduces the Young’s modulus to 72 GPa in the[Mo(Ti₁₃Zr)]Nb₂ alloy. Solution treatment plus subsequent water quenching decreases slightly the Young’s moduli of the suction-cast alloys.