Effect of microstructure variations on the formation of deformation-induced martensite and associated tensile properties in a β metastable Ti alloy
Effect of microstructure variations on the formation of deformation-induced martensite and associated tensile properties in a β metastable Ti alloy
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DOI：
10.1007/s11661-000-0105-3
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发表时间：
2000-04-01
影响因子：
2.8
通讯作者：
Philippe, MJ
中科院分区：
文献类型：
--
作者：
Grosdidier, T;Combres, Y;Philippe, MJ
本文重点讨论微观结构对亚稳态 β 钛合金 (β-Cez) 不同变形机制活性的影响以及由此产生的机械行为。生产了各种类型的微观结构，具有给定的 β 相体积分数（100 或 90 pet）。这些微观结构的不同之处在于其β晶粒的尺寸以及初级α粒子的分布、形状和尺寸。还开发了一种统计方法来表征各种微观结构之间 β 相化学的微小变化。结果表明，即使β相体积分数相似，微观结构的变化也会强烈影响合金的机械响应。机械响应由该合金中两种变形模式之间的相互作用控制：α“变形诱发马氏体的形成和滑移的激活。应力诱发马氏体更容易形成，导致表观屈服应力更低，加工硬化响应更好。相反，当滑移单独激活时，获得的加工硬化非常有限。马氏体相变发生能力的差异是可以理解的 通过考虑 β 相化学性质以及晶粒尺寸和位错引起的约束效应对 M-s 和 T-0 的影响。
This article focuses on the effect of the microstructure on the activity of different deformation mechanisms and the resulting mechanical behavior of a metastable beta Ti alloy (beta-Cez). Various types of microstructures were produced, with given volume fractions of beta phase (100 or 90 pet). These microstructures differed in the size of their beta grains as well as in the distribution, shape, and size of the primary alpha particles. A statistical approach was also developed to characterize small variations in chemistry of the beta phase between the various microstructures. It is shown that, even for similar volume fractions of beta phase, changes in the microstructure strongly affect the mechanical response of the alloy. The mechanical response is controlled by the interplay between the two deformation modes operating in this alloy: formation of alpha" deformation-induced martensite and activation of slip, The easier formation of stress-induced martensite leads to lower apparent yield stresses and a better work-hardening response. On the contrary, very limited work hardening is obtained when slip is activated solely. The differences in the ability of the martensitic transformation to occur can be understood by considering the effect on M-s and T-0 of both the chemistry of the beta phase and of constraining effects due to grain sizes and dislocations.