| The conventional magnesium sheets mainly manufactured with the hot-rolling and extrusion, and which have the long flow of process, low efficiency, high cost and price. Recently, as the breach of the process in the twin-roll cast (TRC), the technology of twin-roll cast with high efficiency and short flow process are becoming the mainstream of the manufacture of magnesium sheets. However, the plastic deformation behaviors of TRC-Mg sheets hadn't been systemic research, and there weren't the reports of the study about the direct deep-drawing performance of TRC-Mg sheets. In order to explore a high efficiency and short low process way of the direct deep-drawing TRC-Mg, and boost the industry of magnesium, we investigated the thermo-plasticity deformation behaviors and the process of warm deep-drawing of TRC-Mg sheets.Since there are fine and high solid fraction semi-solid structure grains in the TRC-Mg sheet, the solid particles constitute a network and aggregation. The construction of network and aggregation will be breakout when the strain up to critical strain during the high temperature deformation, and the phenomena of gliding, wheeling and transposition appear among the solid particles. So we considered that the phenomena of gliding, wheeling and transposition which appear among the solid particles in the hot deformation, based on the non-Newtonian shear viscosity model of amorphous metals, using the mixture law to mix the slid and twin, we got the semi-solid metal mixture flow stress model for the TRC-Mg. The new mixture flow stress model could serve as two conditions. When the Zener-Hollomon parameter (Z) is less than the critical value Zo (1.54E11), the dominant mechanism of TRC-Mg is slip. When the Zener-Hollomon parameter (Z) is higher than the critical value Zo (1.54E11), the dominant mechanism of TRC-Mg is twining. Comparison with the J.J.Jonas (based on the mechanism of slip) and M.R.Barnett (based on the mechanism of twin at low temperature) models indicated that the simulated stress-strain curves calculated by J.J.Jonas model occurred biggish error in the low Z region, and our new mixture model shown fitting the experiment data very well. In the high Z region, the error of calculated by J.J.Jonas model ascended, but M.R.Barnett and the new mixture model also shown the high precision. And the new mixture model was more accurate than M.R.Barnett model. The mentioned above means that the new semi-solid mixture model is reasonable and it can reflect the deformation characteristic of the TRC-Mg.Generally, the processing map was used to establish the working parameters of the materials. Whereas the working parameters obtained by the processing map is rough. In order to obtain the precise working parameters, the processing map, the effective diffusion coefficient and activation energy map of the alloy were established. Combining the processing map, effective diffusion coefficient and activation energy map obtained the optimum conditions for thermo-mechanical processing. The optimum conditions are as follows:a) At temperature range of 568K to 603K and the strain-rate range from 7×10-3 to 2×10-3S-1. It adapt to the high temperature creep forming. b) At the temperature range of 583K to 613K and the strain-rate range from 0.07 to 0.7 S-1. It adapt to the forging, extrusion and rolling. C) At temperature range of 538K to 553K and the strain-rate range from 0.001 to 0.002S-1. It adapt to the warm deep-drawing. This analysis way is adapted to establish hot working parameters of others metal materials.The dynamic recrystallization (DRX) can be generated easily during the high temperature deformation for the magnesium alloys. It resulted in the sharp soften phenomena. So the calculating equation of blank holder force (BHF) based on the Fields-Backofen materials model wasn't fit to the deep-drawing of TRC-Mg sheets. In order to optimized control the BHF in the process of deep-drawing cylinder parts, the variable BHF engineering equation of the curve of minimum wrinkles of TRC-Mg sheets was concluded out by the aid of consulting correlative energy conversation theorem, which based on the new flow stress model. The calculated data using the new model fit the tested data very well when the TRC-Mg blank deep-drawing at the temperature from low temperature to high temperature. In addition, according to the practical working-condition, the three segment way of load variable BHF was adopted to the hot deep-drawing of TRC-Mg sheets. The results revealed that limit drawing ratio (LDR) of the TRC-Mg sheets can be improved by loading the variable BHF.To solve the problem of the poor warm deep drawability of twin-roll cast AZ31B Mg alloy sheet, a warm deep drawing process by utilizing a pre-forming approach which based on the theoretics of dynamic recrystallization (DRX) and static recrystallization was proposed. Orthogonal test design for optimization the working parameters shown that the influence of the pre-forming had become the main factor in the deep-drawing of TRC-Mg sheets. And obtained the optimization working parameters were as follows:punch velocity 45mm/min,strain of pre-forming 16 %,eformation temperature 220℃. The warm deep-drawing experiments of twin-roll cast AZ31B Mg alloy sheets were examined by utilizing a pre-forming approach at temperature range from 20 to 220℃. It is indicated that the deep drawing performance has been significantly improved by utilizing a pre-forming approach. The punch temperature range of 20-95℃was recommended to obtain the best drawability for the twin-roll cast AZ31B Mg alloy sheet. It is found that the twin-roll cast AZ31B Mg alloy sheet was of good deep drawability at forming temperature range of 160-220℃with the higher limit drawing ratio up to 2.26. The dynamic recrystallization (DRX) grains of the workpieces increased gradually with the increase of temperature. And the DRX grains distribution of the materials was more well-distributed, when the workpieces obtained at temperature of 220℃.
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