Microstructure evolution of 2195 Al-Li alloy subjected to high-strain-rate deformation

作者：Yang, Yang; Ma, Fei^*; Hu, Hai Bo; Zhang, Qing Ming; Zhang, Xiao Wei

来源：Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing, 2014, 606: 299-303.

DOI：10.1016/j.msea.2014.03.118

• Dynamic plastic deformation
• Strain rate
• Grain refinement
• Dislocation substructure

2195 Al-Li alloy is firstly processed by means of split Hopkinson pressure bar (SHPB). Two means of loading methods are conducted at room temperature, namely uni-axial impact and multi-directional impact. The nominal strain rates reach up to 1.2 x 10(3) s(1) and 2.8 x 10(3) s(-1) respectively, with the total strain 1.6 and 3.6. TEM microstructure observations reveal that initial coarse grains are refined significantly. The grains of uni-axial impacted sample are elongated, whose width/length average grain sizes are 178 nm and 311 nm. In contrast, the grains of multi-directional impacted sample are equiaxed with an average grain size of 362 nm. Dynamic recovery is suppressed during dynamic plastic deformation (DPD), dislocations could not reach equilibrium states. High densities of dislocations are generated, forming several kinds of configurations. Interactions of dislocation substructures and fragment of grains result in the refinement of grains.

• 出版日期2014-6-12
• 单位中国工程物理研究院; 北京理工大学; 中国工程物理研究院流体物理研究所