HIGH-STRENGTH ALLOY BASED ON ALUMINIUM AND A PRODUCT MADE OF SAID ALLOY

The present invention relates to high-strength aluminium-based alloy of Al-Zn-Mg-Cu system and the article made thereof. Said alloy can be used as a structural material in aircraft- and rocket engineering, and for fabricating the articles for transportation- and instrument engineering. The advantage of the suggested alloy is its high strength and the required level of service properties combined with sufficient technological effectiveness necessary for fabricating various wrought semiproducts, mainly of large sizes. Said alloy has the following composition (in wt %): zinc 7.6-8.6 magnesium 1.6-2.3 copper 1.4-1.95 zirconium 0.08-0.20 manganese 0.01-0.1 iron 0.02-0.15 silicon 0.01-0.1 chrome 0.01-0.05 nickel 0.0001-0.03 beryllium 0.0001-0.005 bismuth 0.00005-0.0005 hydrogen 0.8 x 10 - 2.7 x 10 and at least one element from the group including titanium 0.005-0.06 boron 0.001-0.01 aluminium - balance. The following conditions should be observed: the sum of zinc, magnesium, copper should not exceed 12.5 %; the sum of zirconium, manganese, chrome and nickel should not exceed 0.35%; the ratio Fe:Si should not be less than 1.2. Said alloy is recommended for use as a structural material for main members of aircraft airframe (upper skin, stringers of the wing, loaded beams, etc.