Kou Wenjuan, Sun Qiaoyan, Xiao Lin, Sun Jun
State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, P. R. China.
Sci Rep. 2019 Mar 25;9(1):5075. doi: 10.1038/s41598-019-41574-7.
Excellent stability of plasticity and high strength are acquired in Ti55531 alloy micropillars via introducing a high density of deformable nanoscale α phase into a β matrix. The yield strength of the pillars is as high as 2.26 GPa irrespective of pillar sizes ranging from 6 to 0.3 μm, which is high enough to activate dislocation slip both in ductile α precipitates and the β matrix. The harmony slip model was proposed to interpret slip transmission between the nanoscale α phase and the divided β matrix, and both α and β accommodate their individual plasticity during compression. This results in an excellent combination of high strength and stable plasticity in Ti55531 alloy micron-to submicron pillars. The results highlight the novel strengthening and toughening mechanisms of nanostructured alloys and a specific type of microstructure that exhibits stable plasticity for nano/microdevices.
通过在β基体中引入高密度的可变形纳米级α相，Ti55531合金微柱获得了优异的塑性稳定性和高强度。无论柱体尺寸在6至0.3μm之间如何变化，柱体的屈服强度高达2.26 GPa，这足以在韧性α析出相和β基体中激活位错滑移。提出了协调滑移模型来解释纳米级α相和分割的β基体之间的滑移传递，并且α相和β相在压缩过程中都能适应各自的塑性。这导致Ti55531合金微米至亚微米柱体具有高强度和稳定塑性的优异组合。这些结果突出了纳米结构合金新颖的强化和增韧机制，以及一种对纳米/微器件表现出稳定塑性的特定微观结构类型。
