1 College of Mechanical and Electrical Engineering, Hunan University of Science and Technology, Xiangtan 411201, Hunan, China 2 Key Laboratory of High Temperature Wear Resistant Materials and Preparation Technology of Hunan Province, Hunan University of Science and Technology, Xiangtan 411201, Hunan, China
To study the effect of temperature and strain rate on the dynamic mechanical properties and microstructure evolution of 2519A aluminum alloy, the dynamic mechanical properties of 2519A aluminum alloy were measured by dynamic impact compression tests using the split Hopkinson pressure bar at different temperatures (-90-350℃) and different strain rates. The dynamic mechanical properties were analyzed, and the microstructure after impact was also investigated by metallographic microscope and transmission electron microscopy (TEM). The results show that the impact flow stress decreases rapidly at 250-350℃. The deformation band is the main deformation character, and obvious dynamic recovery and dynamic recrystallization are generated, so the dislocation density is low. Adiabatic shear band (ASB) occurs when the alloy deforms after dynamic impact at 20-150℃. The strain rate strengthening effect changes at room temperature with strain rate 8200s-1. When temperature drops to -90℃, some short and discontinuous microcracks appear within the ASBs, and some long strip particles are broken by brittle fracture.
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