Microstructure and temperature monitoring during the hot rolling of AZ31

Twinning-induced negative strain rate sensitivity in wrought Mg alloy AZ31

“…The strain rate effect on slip is taken into account by taking m values as positive, whereas strain rate is assumed to influence twinning process by affecting twinning rate such that is increased more rapidly with strain and is Table 1 Fitting parameters employed in the present constitutive model (Eqs. (2) and (3)). The fitting parameters given above have been adjusted from the values in [12,13].…”

“…On the other hand, the use of wrought magnesium alloys for structural applications is restricted by their limited low-temperature formability [1,2]. Consequently, there is extensive research into the deformation behavior of wrought magnesium alloys.…”

Influence of strain rate on hot deformation behaviour and texture evolution of AZ31B

“…The as cast material was homogenised at 450uC for 4 h, which was found to give a consistent hot deformation behaviour. 9 This resulted in a coarse grain size of y200 mm measured by image analysis. To investigate the effect of strain rate on the microstructure and texture evolution, two series of tests were performed on the material in the temperature range from 300 to 450uC.…”

“…3,[5][6][7] However, the effect of strain rate, especially high strain rates of .1 s 21 , at which most secondary forming processes are performed, has rarely been examined systematically. A study by Lee et al 8 on the effect of strain rates from 0?01 to 10 s 21 to a strain of 0?1 showed that the twinning fraction increases with increasing strain rate at 573 K. Essadiqi et al 9 also studied the effect of high strain deformation using a cam plastometer. They found that with increasing strain rate, for a given strain, the recrystallised grain size becomes finer, and the strain triggering dynamic recrystallisation (DRX) increases.…”

The Impact of Melt-Conditioned Twin-Roll Casting on the Downstream Processing of an AZ31 Magnesium Alloy

“…[5][6][7] Several procedures have been developed to produce fine-grain structures in magnesium alloys, including powder metallurgy, [8] rapid solidification, [9] and severe plastic deformation, [10][11][12] but only small quantities of material can be obtained from these process routes. Although thermomechanical processing through repetitive hot/ warm rolling/extrusion of ingot slabs combined with heat treatment can produce well-refined microstructures, [13][14][15] it is extremely costly and has an adverse effect on the anisotropy and ductility as strong basal texture develops. [14,16,17] Twin-roll casting can produce a magnesium alloy strip directly from the melt with a thickness less than 6 mm, eliminating the need for the use of a breakdown mill and most of the passes in the finishing mill that are required in conventional processing.…”