METHOD TO PRODUCE SUPERPLASTIC SHEET FROM ALUMINIUM ALLOY OF ALUMINIUM-LITHIUM-MAGNESIUM SYSTEM Russian patent published in 2012 - IPC C22F1/04 

FIELD: metallurgy.

SUBSTANCE: from an ingot a stock of rectangular section is produced, which is square in plan, with the ratio of thickness and width equal to 0.17-0.33, stock deformation is carried out with equal channel angular pressing at the angle of channels crossing 90°, temperature of 320-330°C, a number of stages corresponding to true deformation 4, with back pressure, equal to 40-50% of the applied pressure, and rotation of the stock after each stage by the angle of 90° around the normal line to the largest area of stock section and additionally by 180° around the longitudinal axis, the pressed stock is exposed to isothermal rolling in the range of temperatures 320-330°C, then tempering is carried out with 450±10°C after soaking for 2 hours, and repeatedly heated to 120°C, soaked for 5 hours and cooled with the furnace.

EFFECT: method makes it possible to superplastic sheets from an aluminium alloy of a system of Al-Mg-Li with high isotropy of mechanical properties and higher indices of superplasticity under lower temperatures and high speeds of deformation due to preservation of homaxonic ultra-fine-grain structure.

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