Comparative study of hot-processing maps for 6061 aluminium alloy constructed from power constitutive equation and hyperbolic sine constitutive equation

Two hot-processing maps were constructed from different constitutive equations using high temperature compression data to optimise hot-processing parameters for 6061 aluminium alloy. The results show that the flow behaviour of the alloy may be represented by a hyperbolic sine-type equation with deformation activation energy of 343·7 kJ mol⁻¹. Dynamic recovery and dynamic recrystallisation concurrently proceeded during high temperature deformation of the alloy. The hot-processing map constructed from the hyperbolic sine constitutive equation is more suitable for optimising hot-processing parameters and for controlling the microstructure of the alloy. High deformation temperature and low strain rate favour the hot workability of the alloy. The optimum deformation condition for the alloy is 753 K/0·001 s⁻¹. The instability domain occurs at lower deformation temperature than 653 K.