Superplastic Forming of AZ31 Magnesium Alloy Sheet into a Rectangular Pan

Abstract

Superplastic behaviour of Mg-alloy AZ31 was investigated to clarify the possibility of its use for superplastic forming (SPF) and to accurately evaluate material characteristics under a biaxial stress by utilizing a multi-dome test. The material characteristics were evaluated under three different superplastic temperatures, 643, 673, and 703 K in order to determine the most suitable superplastic temperature. Finite Element Method (FEM) simulation of rectangular pan forming was carried out to predict the formability of the material into a complex shape. The superplastic material properties are used for the simulation of a rectangular pan. Finally, the simulation results are compared with the experimental results to determine the accuracy of the superplastic material characteristics. The experimental results revealed that the m values are greater than 0.3 under the three superplastic temperatures, which is indicative of superplasticity. The optimum superplastic temperature is 673 K, at which a maximum m value and no grain growth were observed. The results of the FEM simulation revealed that certain localized thinning occurred at the die entrance of the deformed rectangular pan due to the insufficient ductility of the material. The simulation results also showed that the optimum superplastic temperature of AZ31 is 673 K.

Cavity minimization and uniformity studies on superplastic forming of thin eutectic Pb–Sn sheet by optimum loading and preforming

“…The term optimum means achieving largest amount of deformation without thinning at the shortest forming time possible [1].…”

The finite element simulation of high-temperature magnesium AZ31 sheet forming

“…As is common practice in high-temperature material model development, [16][17][18][19][20][21][22][23] tensile strain-rate-change (SRC) tests were used to generate the necessary data to construct a material model for a fine-grained Mg sheet. 24 The SRC test data are plotted in Figure 2 as logarithm of true-strain rate versus logarithm of true stress (at a true strain of ε = 0.2), at temperatures ranging from 350 to 500C.…”

Influence of thermomechanical processing on superplastic forming of Mg–Al alloys

“…Five direct pole figures were measured, namely (0002), (10-10), (11)(12)(13)(14)(15)(16)(17)(18)(19)(20), (10)(11), (10)(11)(12).…”

“…Several reports have indeed demonstrated the superplastic formability of Mg alloys [15][16][17][18][19][20]. However, further research on the relationship between processing, microstructure and post-forming properties of these materials under different forming conditions is still needed.…”