In recent years, the movement for banning the sale of gasoline cars and diesel vehicles, especially in Europe, and allowing only electric passenger cars has been accelerated. For examples, Germany’s federal council, the Bundesrat, has passed a resolution calling for a ban on combustion engine cars by 2030. If the ban were to go through, German citizens would only be permitted to purchase electric or hydrogen-fueled cars. In Norway, until 2025 there is a movement for legislation prohibiting the registration of new gasoline passenger cars and diesel cars. Beginning in 2025 in the Netherlands, a bill prohibiting the sale of new cars gasoline and diesel vehicles was submitted to Congress. Under the circumstances, the demand for light-weight products for automotive industries has increased due to global trends in environmental preservation. Although demands for magnesium has risen dramatically, production of magnesium alloy sheet still remains at a very low level. This study seeks to establish a guideline for roll design in the roll forming of wrought magnesium alloys to extend practical use of roll-formed products of wrought magnesium alloys. A three-dimensional elasto-plastic analysis by the finite-element method has been conducted to express exact roll-forming behavior of wrought magnesium alloys that have different stress-strain curves in tension and compression. Simple V-sections were formed by a tandem six-stand roll forming machine to demonstrate the effectiveness of the simulation methods with different stress-strain curves in the case of tension and compression. Also, spring-back analysis has been performed to investigate the exact cold roll-forming phenomenon for wrought magnesium alloy sheets.

In this paper, twin roll casting of magnesium alloys with high aluminum content such as, Mg-11 mass%Al-0.2 mass%Mn, Mg-12 mass%Al-0.2 mass%Mn, Mg-13 mass%Al-0.2 mass% have been performed for the purpose of use as an original material for hot forging. Also the mechanical properties of the cast materials were examined. A 10 miri-meters thick strip was cast by the use of a horizontal twin roll caster. The microscopic observation was conducted to investigate into the precipitation of the metal compounds such as Mg17Al12, and the Vickers hardness of the cast strips test were performed. From the result of the roll casting experiments, a 10 mm thick strip was continuously cast at a roll speed of 3.1 m/min. The average grain size of the casting strips was about 46 micron meters. When the aluminum content was 13%, the hardness of the twin roll cast (TRC) strips became 1.7 times higher than that of extruded AZ 31. Also, a uniaxial compression test at elevated temperature was conducted to obtain a true strain-true stress curve for examining possibility of direct hot forging (DHF) of TRC magnesium alloys with high aluminum content.

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