Deep Drawing of AZ31 Magnesium Alloy at Elevated Temperatures in Annealed ConditionPages 355-363
C. Jai Shiva Rao Abstract:
The lower density and higher specific stiffness and strength of magnesium alloys make them appealing; nevertheless, the strengthening of the secondary phase and the lack of slip mechanisms reduce formability, particularly for the stronger magnesium alloys such as AZ31. Experiments examining the formability of AZ31 sheets in an annealed condition revealed that AZ31's improved plastic flowability causes the sheet's depth of forming to grow dramatically to 32 mm when the temperature is raised from 250 to 350°C. At 350°C, there was more thinning. A 350°C temperature, 8 kN blank-holding force, and 4 mm/min drawing speed are the ideal process conditions for hot deep drawing. The microstructural evolution demonstrates that twinning significantly accommodates plastic deformation of the AZ31 magnesium alloy at high temperatures. By overcoming the challenges of the reinforcing phases, this twinning deformation mechanism is triggered by heating and achieves improved forming properties.
Keywords:
AZ31 magnesium alloys,
Deep drawing,
Annealing,
Depth of forming,
Thinning,
Microstructural evolution
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