Low-temperature tensile behaviours of 6061-T6 aluminium alloy: Tests, analysis, and numerical simulation

This paper made efforts on tensile behaviours of aluminium alloy (AA) 6061-T6 at low temperatures (T). To investigate low-temperature tensile behaviours of 6061-T6 AA, this paper carried out 24 tension tests on AA coupons at varying T levels of 20, −30, −60, and −80℃. The tests revealed that reducing T from 20 to −80℃ improved mechanical properties of 6061-T6 AA including improved elastic modulus by about 15%, increased yield strength by 9%, and improved ultimate strength by 10%; however, decreasing the low temperature from 20 to −80℃ has marginal influences on the ductility of 6061-T6 AA. In addition, the ambient- and low- temperature stress–strain (σ-ε) curves of 6061-T6 AA exhibited close behaviours. Analytical constitutive models were proposed for 6061-T6 AA. These proposed analytical models predicted well low-temperature σ-ε behaviours of 6061-T6 AA. FEMs with continuum damage mechanics were also developed for the low-temperature tensile σ-ε behaviours of 6061-T6 AA. It was proved that the developed FEM provided reasonable simulations on engineering σ-ε curves of 6061-T6 AA at different low temperatures.