Numerical simulation on shape distortion of superplastic forming Ti-6Al-4V cylinder

The dimensional accuracy and shape distortion caused by the contraction of ZG35Cr24Ni7N refractory steel die when cooling after superplastic forming were analyzed using MSC. MARC. And the influence of different processing parameters on the shape distortion was also studied. The result show that during the cooling process from 930 to room temperature, when the temperature decreases to 915°, the shape distortion begin to generate, and increasing with the reducing of the temperature up to 800°. The shape distortion increased with the rising of friction coefficient, this is because the Ti-6Al-4V cylinder can't release the volume through sliding but the plastic deformation when the friction exists. So the plastic deformation increased with the rising of friction and leading to the increase of shape distortion.