亚微米尺度下Beta钛合金单晶力学行为及变形机理研究

项目名称： 亚微米尺度下Beta钛合金单晶力学行为及变形机理研究

项目编号： No.51271136

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 一般工业技术

项目作者： 肖林

作者单位： 西安交通大学

项目金额： 80万元

中文摘要： 通过对不同尺寸Ti-36Nb-2Ta-3Zr-0.3O橡胶金属和Ti-10V-2Fe-3Al (Ti1023)两种Beta钛合金单晶拉伸和压缩加载下宏观变形行为和微观变形机理的研究，建立不同位向下微尺度单晶流变应力、塑性变形随单晶尺寸的变化规律。弄清非传统位错滑移和孪生等塑性变形方式下，亚微米尺度下橡胶金属本征塑性变形机理及其尺寸依赖关系。确定扩展剪切带、严重扭曲的纳米畴和应力诱发马氏体相变的临界分切应力对材料尺寸的依赖关系和应力应变突变的物理极限尺寸范围。分析亚微米尺度下橡胶金属内部非位错塑性变形与传统Ti1023钛合金滑移、孪生塑性变形时应力诱发马氏体相变对材料尺寸的依赖关系和亚微米尺度下材料力学行为的尺寸效应之间的本征关系。探讨橡胶金属内部不同尺度第二相或点缺陷塑性变形行为对微尺度材料整体力学性能尺寸效应的影响。为亚微米尺度下Beta钛合金塑性变形机理及尺度效应提出一个合理的解释。

中文关键词： Beta钛合金；尺寸效应；塑性稳定性；纳米马氏体；Omega沉淀相

英文摘要： The dependence of mechanical behavior and microscopic deformation mechanism on geometric size will be studied in beta-Ti alloys single crystals of Ti-36Nb-2Ta-3Zr-0.3O gum metal that demonstrates an ultrahigh strength, and Ti-10V-2Fe-3Al (Ti1023) subjected to tensile and compressive deformation in submicron scale. The variety curves of stress-strain as a function of sample size will be measured in Ti alloys single crystals under different orientations. The plastic deformation mechanism and size effect will be systematically studied in gum metal, which appears to deformation by a dislocation-free mechanism triggered by elastic instability at the limit of strength. The critical stresses and their size effect of giant faults, nanodisturbances and deformation-induced martensitic phase transformation will be determined in beta-Ti alloys during plastic deformation. The constitutional relationship between the size effect of martensitic phase transformation and the size effect of mechanical behavior of pillars will be established in gum metal deformed by dislocation-free mechanism and Ti1023 deformed by conventional dislocation slip and twinning. The influence of plastic deformation behavior of second-phase precipitates and nanodisturbances with the fine-scale with respect to the sample pillars on the size effect of mec

英文关键词： Beta Titanium Alloy；Size Effect；Plasticity Stability；Nano-Martensite；Omega Precipitate