HIGH-RESOURCE HIGH-STRENGTH ALUMINUM-ALLOYS

Aluminum alloys used in the aircraft industry have to satisfy the requ irements of high strength at low density, appropriate resistance to di fferent kinds of corrosion, maximum possible rigidity, good adaptabili ty to manufacturing in the metallurgical and machine-building industri es, etc. A new requirement on aircraft materials imposed in the last t wenty years is an elevated resistance to crack propagation, because it is impossible so far to completely eliminate cracks in industrial mat erials. Therefore, aircraft builders have developed the concept of ''s afe vulnerability to damage,'' which permits the presence of cracks in aircraft structures but requires knowledge of the laws of their propa gation. The present work is devoted to a direction in the development of aluminum alloys that provides elevated crack resistance parameters.