Dynamic tensile behavior of Al-6Mg alloy with three treatment states

Abstract
The mechanical properties of Al-6Mg alloy with three treatment states (H112 state, O state and cold extrusion state) were investigated by using INSTRON machine and Split Hopkinson Tensile Bar. Stress-strain curves of Al-6Mg alloy with three treatment states were obtained at quasi-static strain rates 6×10⁻⁴, 6×10⁻³, and 6×10⁻² s⁻¹ and dynamic strain rates 670 ~ 3050 s⁻¹,respectively. The results show that three materials is low sensitive to the strain rate. Mild negative strain rate sensitivity was observed at strain rates 6×10⁻⁴ ~ 6×10⁻² s⁻¹ while a positive strain rate sensitivity was found at strain rates 670 ~ 3050 s⁻¹. The Al-6Mg alloy of cold extrusion state displays highest strength and Al-6Mg alloy of O state displays most ductility, but their advantages decline with the strain rate increasing at dynamic conditions. The fracture surfaces of the tested specimens were examined by SEM. The results show that three Al-6Mg alloys exhibit ductile fracture at all strain rates used.