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In this work, the quasi-in-situ electron backscattered diffraction (EBSD) is employed to investigate the static recrystallization occurring at the interface of deformation twinning interactions in liquid nitrogen temperature (LNT) rolled AZ61 alloy during electric pulse treatment (EPT). It was found that recrystallization nucleation occurred at the 10 1 ¯ 2 tensile twin (TTW) interaction, after which new grains and part of the original grains consumed 10 1 ¯ 2 TTW and grow up. By contrast, recrystallization nucleation occurs not only at the 10 1 ¯ 1 − 10 1 ¯ 2 double twin (DTW) interactions but also within twin boundaries during subsequent EPT. When multiple twins come into being in the exact grain, the recrystallization growth showed obvious directionality: first, recrystallization grains grow along with 10 1 ¯ 1 − 10 1 ¯ 2 DTW and 10 1 ¯ 1 CTW boundaries and consume them; then the 10 1 ¯ 2 TTWs are consumed and the growth direction of recrystallization grains shifts to along with their boundaries. • Static recrystallization induced by twinning-interactions during electric pulse treatment (EPT) has been investigated. • The effects of twinning-interactions on EPT accelerated recrystallization behaviors have been analyzed. • We suggest an effective way to tailor the microstructure of magnesium alloys by LNT rolling and EPT. [ABSTRACT FROM AUTHOR]

In this work, electrical pulse treatment and isothermal heat treatment are employed to tailor the microstructure of the hot-rolled AZ61 alloy. The influence of pulsed current on the crystal growth mechanism and precipitation phase diffusion was investigated. According to the findings, electrical pulses enhance the recrystallization and dissolution of Mg 17 Al 12 precipitate in hot-rolled AZ61 alloy. The recrystallization fraction of EPTed samples is higher than that of the isothermal HTed counterparts. The amount of Mg 17 Al 12 phase is considerably reduced with the increased EPT duration. In contrast, the Mg 17 Al 12 phase fraction in isothermal HTed samples is just slightly changed. The Nernst–Einstein formula indicates that the electrical pulse effectively improves the total diffusion flux in the diffusion system via the coupling of athermal effect and thermal effect. • The recrystallization process and second phase change of AZ61 alloy under electrical pulse treatment (EPT) were studied. • The effect of second phase dissolution during EPT on the quick recrystallization of hot-rolled AZ61 alloy was studied. • We suggest that a good way to change the microstructure of magnesium alloys is to use EPT to speed up recrystallization. [ABSTRACT FROM AUTHOR]

Highlights: [•] We proposed two constitutive equations with varying parameters. [•] The phenomenological equation has high accuracy in a local range. [•] The empirical equation has higher accuracy in a wide range. [•] The two equations have a good ability to model superplastic flow behavior. [Copyright &y& Elsevier]