Flow and fracture behavior of aluminum alloy 6082-T6 at different tensile strain rates and triaxialities

Abstract

This study aims to investigate the flow and fracture behavior of aluminum alloy 6082-T6 (AA6082-T6) at different strain rates and triaxialities. Two groups of Charpy impact tests were carried out to further investigate its dynamic impact fracture property. A series of tensile tests and numerical simulations based on finite element analysis (FEA) were performed. Experimental data on smooth specimens under various strain rates ranging from 0.0001~3400 s-1 shows that AA6082-T6 is rather insensitive to strain rates in general. However, clear rate sensitivity was observed in the range of 0.001~1 s-1 while such a characteristic is counteracted by the adiabatic heating of specimens under high strain rates. A Johnson-Cook constitutive model was proposed based on tensile tests at different strain rates. In this study, the average stress triaxiality and equivalent plastic strain at facture obtained from numerical simulations were used for the calibration of J-C fracture model. Both of the J-C constitutive model and fracture model were employed in numerical simulations and the results was compared with experimental results. The calibrated J-C fracture model exhibits higher accuracy than the J-C fracture model obtained by the common method in predicting the fracture behavior of AA6082-T6. Finally, the Scanning Electron Microscope (SEM) of fractured specimens with different initial stress triaxialities were analyzed. The magnified fractographs indicate that high initial stress triaxiality likely results in dimple fracture.

The Effect of Laser Peening without Coating on the Fatigue of a 6082-T6 Aluminum Alloy with a Curved Notch

“…The material properties of Al 6082-T6 were selected according to the works by Chen et al [21] and Chen et al [22], which present thorough measurements of the hardening parameters, including testing at high strain rates via a split-Hopkinson tension bar. The maximum strain rate measured in Figure 7.…”

Inertial Impact Tests to Identify the Plastic Properties of Metals

“…The material parameters used to describe the impactor and specimens are E = 70 GPa, ν=0.30, ρ = 2700 kg/m 3 , σ 0 = 350 MPa, H = 0.7 GPa and E = 205 GPa, ν = 0.30, ρ = 7850 kg/m 3 , σ 0 = 650 MPa, H = 2 GPa for the aluminum specimen and steel impactor, respectively. Note that aluminum 6082-T6 was selected for the sample since previous studies have shown it is rate-independent over a wide range of strain rates at room temperature [8,9]. Modeling only rate-independent plasticity simplifies both the finite element model and the inverse identification.…”

High-Speed Deformation of Pinless FSWed Thin Sheets in AA6082 Alloy

“…Focusing on the high-speed deformation behavior of 6xxx aluminum alloy series, several researches are available [20,21]. They showed that 6xxx aluminum alloys exhibit low strain rate sensitivity since the softening effect due to adiabatic heating counteracts the rate sensitivity at high strain rates.…”