The Study of Deep Drawability of Al-Mg Alloys with Conical Die

It is generally known that Al-Mg alloy is the most suitable for deepdrawing amongst all kinds of aluminium alloys. This study is to investigate the specific Al-Mg alloy which is the best in deep drawability, strength and weldability. For that purpose, the influences of the magnesium contents, soaking, reduction rate, addition of manganese, chromium and other impurities, annealing temperature were examined.The ingot of 250mm × 150mm × 35mm was rolled down to the sheet of 1.00mm thickness under different conditions. With this sheet, conical die test, tensile test, bending test and Erichsen test were carried out. Used conical die is of 60° in die angle and 19.00mm in die hole diameter. Punch is 17.46mm φ and punch radius is 4.0mm.The findings are as follows:1) Magnesium content does not give much effect to the deep-drawability of the alloy.2) When deep-drawability and stretchability are required, Al-Mg pure binary alloy is recommended, and in this case, lower magnesium content is appropriate in view of the Erichsen value. The properties of this kind of alloy is not affected by iron and silicon content as impurities.3) When bending work has weight, the addition of manganese or chromium is recommendable. The increase in Si and Fe content also shows good result.4) Existance of manganese together with chromium in this alloy makes its drawability and stretchability worse.5) Soaking is good for better deep-drawability.6) Greater cold reduction is better for deep-drawability.7) Higher the final annealing temperature, the better result.8) Under the annealing temperature of 350°C and more, mechanical properties do not show any change, while the deep-drawability is improved. There will be any correlationship between deep drawability and machanical properties in such range of annealing temperature.