METHOD FOR OBTAINING SUPERPLASTIC SHEET OF HIGH-STRENGTH ALUMINIUM ALLOY Russian patent published in 2012 - IPC C22F1/04 

FIELD: metallurgy.

SUBSTANCE: invention is intended for optimisation of technology for obtaining aluminium alloy sheets of Al-Ni-Zn-Mg-Cu-Zr, system, which are meant for superplastic formation. Possibility of sophistication of geometrical shape of items due to superplastic deformation exceeding 500% prior to destruction at increased rates (up to 1×10^-2 s^-1) is provided due to increased content of zirconium in alloy (at least 0.25%) by means of accelerated cooling at the rate of not less than 15 K/s at crystallisation of ingots, as well as combination of thermal and deformation treatments of alloy in compliance with which the melt is poured from temperature of 800±5°C, homogenising annealing is performed; hot rolling is performed at 410±10°C with crimping of 80%; then, soft annealing is performed at 480±5°C during 30 minutes with further slow cooling with furnace; cold rolling is performed at one stage with crimping of 60%.

EFFECT: obtained sheet has relative elongation δ>500%, σ_t=8 MPa at superplastic deformation temperature of 515°C and constant deformation speed of 1×10^-2s^-1.

2 dwg, 3 ex