A STUDY OF THE SUPERPLASTIC ISOTHERMAL DEFORMATION-BEHAVIOR OF ALUMINUM-ALLOY LY12

This paper studies the softening-treatment technology of aluminium all oy LY12 and the subsequent superplastic mechanical behavior of the mat erial. The research results show that the resistance to deformation is reduced by 20-30% after the as-supplied LY12 has been softened. The d eformation technology parameters after the softening treatment are: a deformation temperature of 420-440 degrees C; a strain-rate of 5 x 10( -3)/s; when the flow stress is less than 15 MPa, the strain is compara tively stable within one minute under different temperature conditions ; when the stress is greater than 20 MPa and the deformation temperatu re is increased, the strain increases very quickly with further elapse of time. These referential technological parameters provided are used for complex plate reinforcement in superplastic isothermal die forgin g.