EFFECT OF ELECTRIC CURRENT PULSE ONSUPERPLASTICITY OF ALUMINIUM ALLOY 7475
(Department of Mechanical Engineering，Hubei Institute of Technology，Wuhan 430068)
Abstract: The superplastic deformation of aluminium alloy 7475 applied electric current pulse has been studied. The results presented chat applying a high density current pulse raises hoth the elongation rate and Ehe m value .and makes supperior superplastic properties at high strain rate of 10-2s-1，the op-timum deformation temperature could move from 530 ℃ to 480---510 ℃，TEM observation showed thesuperplastic deformation of the alloy is the results of grain boundary slips and dislocation slips in grains under funetion of the electron wind; the intergranular tear is a main behavior of fracture of the alloy.
Key words: aluminium alloy 7475 superplasticity electric current pulse