METHOD OF MANUFACTURING PRODUCTS FROM ALUMINUM/MAGNESIUM/LITHIUM ALLOY Russian patent published in 2004 - IPC

FIELD: nonferrous metallurgy.

SUBSTANCE: invention relates to a method for manufacturing structural parts of aircrafts from aluminum/magnesium/lithium alloys. Method comprises preparing aluminum alloy containing, wt %: magnesium 3.0-3.6, lithium 0.4-3.0, zinc up to 2.0, manganese up to 1.0, silver up to 0.5, iron up to 0.3, silicon up to 0.3, copper up to 0.3, 0.02-0.5 of at least one element selected from group including scandium 0.010-0.40, hafnium 0.010-0.25, titanium 0.010-0.25, vanadium 0.010-0.30, neodymium 0.010-0.20, zirconium 0.020-0.25, chromium 0.020-0.25, yttrium 0.005-0.20, beryllium 0.0002-0.1, and inevitable impurities. Alloy is cast into ingot, which is then heated and subjected to hot rolling to form hot-rolled intermediate product. The latter is rolled in cold state both along its length and along its width resulting in reducing thickness of hot-rolled intermediate product by at least 15%. Cold-rolled product is then heated by 465-565^оС during 0.15-8 h to form solid solution. The latter is cooled to temperature below 150^оС with cooling velocity at least 0.2^оС/sec and cooled product is aged to give sheet or thin-sheet article showing minimum yield point 260 MPa and minimum tensile strength 400 MPa at least in L and LT directions; minimum yield point 230 MPa and minimum tensile strength 380 MPa in direction at angle 45^о to L direction; and minimum value of crack resistance 80 MPa·m^1/2 in T-L direction for samples 400 mm wide with central crack used for determining crack resistance.

EFFECT: increased crack resistance and reduced anisotropy of mechanical properties.

11 cl, 2 dwg, 8 tbl, 2 ex