Method for producing half-finished products made of aluminium alloys and an article manufactured with the aid of said method

Abstract

The present invention relates to the method of fabrication of wrought semiproducts from high strength aluminium-based alloys, and fabrication of articles from such semiproducts e.g frames, fittings, beams, etc. used in aerospace engineering and transportation facilities. The suggested method comprises: casting an ingot, homogenization, forging the ingot, extrusion of the wrought billet, solution heat treatment, cold working in two steps: 1. stretching with 1-5% permanent set, 2. multi-axial shaping of the billet by bending while simultaneously performing the local plastic deformation of the billet by compressing (1-20%) the joint places of the blank parts being disposed at an angle of 45-135° to each other; two stage ageing: 1 st stage=heating to 90-120° C. for 5-24 hours; 2 nd stage=heating to 160-190° C. for 5-20 hours. The suggested method allows to fabricate long, irregular-shaped semiproducts from wrought aluminium-based alloys having high strength and fracture toughness and low level of residual stresses, thereby providing the fabrication of products without any distortion or buckling upon machining.

1 . Method of fabrication of semiproducts from aluminium-based alloy, which method comprising casting an ingot, homogenization, forging an ingot, extrusion of the forged billet, solution heat treatment and quenching, cold working and ageing of the billet, wherein cold working after solution heat treatment and quenching is performed in two steps, the first step of which comprises stretching of the as-quenched extruded billet, the second step comprises multi-axial shaping of the billet by bending while simultaneously performing the local plastic deformation of the billet by compressing the joint places of the blank parts, said parts being disposed at a predetermined angle to each other.  
     
     
         2 . Method of  claim 1 , characterized in that stretching is performed with 1-5% permanent set without heating.  
     
     
         3 . Method of  claim 1 , characterized in that multi-axial shaping of the billet by bending is performed in a die without heating, but providing local compression with 1-20% permanent set.  
     
     
         4 . Method of  claim 1 , characterized in that ageing is performed in two stages: the first stage comprises heating to temperature 90-120° C. for 5-24 hours, the second stage comprises heating to temperature 160-190° C. for 5-20 hours.  
     
     
         5 . Method of  claim 1 , characterized in that the blank parts are: a longitudinal rib and a plate disposed at the angle 45-135° to each other.  
     
     
         6 . The article made of aluminium-based alloy, characterized in that said article is fabricated by the method according to claims  1 - 5 .