Study on High-Speed Tensile Mechanical Properties and Deformation Mechanism of 2195 Al-Li Alloy Sheet

Abstract:

In order to investigate the dynamic mechanical properties and deformation mechanism of 2195 Al-Li alloy as quenched. The high strain rate tensile experiments were carried out by the split Hopkinson tension bar equipment. Experimental strain rate ranges from 1000 s-1to 4500 s-1. The texture types and microstructure evolution of the alloy in different strain rates were analyzed by EBSD. The results show that strength and elongation of the alloy increase gradually with strain rate. The ultimate tensile strength and elongation reach 396 MPa and 63% respectively in 4200 s-1. Compared with quasi-static tensile test, the elongation is significantly improved. According to the analysis of EBSD results, with increase in strain rate, the proportion of small-angle grain boundaries and the average KAM increase at the same time. And the strength and volume fraction of Goss texture and S texture increase with the increase in strain rate. In high strain rate tension, not only the plastic deformation of soft-oriented grains is more sufficient, but also more coordinated deformation of hard-oriented grains can be initiated. Furthermore, the deformation mechanism in high strain rate tension is revealed