METHOD OF THERMAL WORKING OF ALUMINIUM ALLOYS Russian patent published in 1994 - IPC

FIELD: metallurgy. SUBSTANCE: method involves the annealing at 385-420 C for 1-8 h, additional annealing at 495-520 C for 3-12 h, heating up to homogenization temperature (5-30 C lower of solidus point), holding at this temperature and cooling. Method provides the following plastic properties of ingots: at 400° C σ= 80-100 %, a_н = 2.0-3.2 kgf/cm²; at 450° C σ = 100 -135 %, a_н= 2.6-3.8 kgf/cm²; at 500° C σ = 120 - 150 %, a_н= 3.5 - 4.8 kgf/cm². Properties of pressed semifinished product treated by proposed method are the following: σ_в= 50-54 kgf/mm, σ_0.2= 42-47.0 kgf/mm, δ = 7,5 - 9,0 %, viscosity rupture KDnIc