Finite element analysis considering heat transfer in sheet metal forming of AZ31

AZ31 합금 성형에서의 열전달을 고려한 유한요소해석

In this work, the influences of tool temperature on the formability of AZ31 sheet material in warm deep drawing processes of square cup were investigated. Deep drawing tests under different tool temperatures for magnesium alloy sheet at elevated temperature $250^{\circ}C$, where AZ31 sheet shows a good formability, and FE analyses were carried out. The successfully formed part without any defects was obtained when temperature of tool was over $100^{\circ}C$ while the fracture was occurred at the corner of the square cup below $100^{\circ}C$. It is shown that lower temperature of tool than that of magnesium sheet causes the temperature drop of the material by heat transfer and thus Interrupts the dynamic recrystallization of it. Therefore, in order to obtain successful part of magnesium alloys, it is necessary that the tool temperature is limited to the same or slightly lower temperature than sheet material.