METHOD FOR OBTAINING SUPERPLASTIC WORKPIECES FROM ALUMINIUM ALLOYS BASED ON ALUMINIUM-MAGNESIUM-SCANDIUM SYSTEM Russian patent published in 2012 - IPC C22F1/47 

FIELD: metallurgy.

SUBSTANCE: method involves casting of an ingot and obtaining of workpiece from it using equal-channel annular pressing with back pressure. Reduction of duration of shape-generating operations performed in the mode of high-speed superplasticity, as well as reduction of the workpiece heating time is provided due to the fact that prior to the ingot casting, the molten metal is heated up to 760-800°C and exposed at that temperature during 0.5-1.0 h; ingot is cast by means of semi-continuous casting to sliding crystalliser; cast ingot is annealed at temperature of 360-380°C during 3-8 h; workpiece of rectangular section, which is square in plan view, is obtained from ingot with ratio of thickness to width of 0.17 to 0.33; deformation of workpiece obtained from the ingot by pressing is performed at crossing angle channels of 90° at temperature of 305-325°C with number of passes of 4 to 8, which corresponds to true deformation of ~4 to ~8, with back pressure value equal to 30-40% of the value of applied pressure, with rotation of workpiece after each pass through 90° relative to the axis perpendicular to large edge of workpiece and passing through the centre of workpiece; then, workpiece is subject to rolling at temperature of previous pressing with total swaging of 80-95% at temperature of working rolls of rolling mill, which is equal to rolling temperature.

EFFECT: optimisation of superplastic shaping process of products of irregular shape.

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