METHOD FOR PRODUCING THIN SHEET FOR SUPERPLASTIC MOLDING FROM ALLOYS OF AL-MG-LI SYSTEM Russian patent published in 1996 - IPC

FIELD: metallurgy. SUBSTANCE: method involves effectuating homogenizing annealing of ingots at 475-520 C for 3-8 hours, hot rolling, quenching from 490-520 C, heterogenizing annealing at 385-410 C for 1-2 hours; cold rolling sheets to obtain final thickness with intermediate annealing cycles at 385-410 C for 5-30 min at each 30-55% deformation extent cycle, with cooling, upon heterogenizing and intermediate annealing cycles, being conducted at cooling rate of 350-750 C/sec. Method allows fine-grain recrystallization structure with grain size of 10 microns to be obtained and high characteristics of superplasticity to be provided (flow stress at 470 C and deformation rate of 10^-4 c ^-1 is 1.8 MPa, specific elongation is 350%, speed sensitivity coefficient is ~ 0.56). EFFECT: increased processing plasticity and reduced duration and number of technological processes, with superplasticity factor being maintained at required levels. 2 tbl