Crack resistance of rolled semiproducts made of alloys of the system Al-Cu-Mg in different structural states

Abstract

1. An increase of the volume fraction of particles of excess phase from 1 to 2.7\2-3.5% leads to a decrease of Kcy by 5\2-10% and an increase of the growth rate of the fatigue crack by a factor of 1.5\2-2 for \gDK=850\2-1000 N/mm3/2. When the volume fraction of excess phases is 4.5%, the growth rate of the fatigue crack increases even with low values of ΔK. 2. In comparison with natural aging, artificial aging leads to reduced characteristics of static crack resistance and increased growth rate of the fatigue crack in the entire investigated range of \gDK. 3. The use of thermomechanical treatment in the production of rolled plates makes it possible to increase the strength properties approximately by 10% while the rupture work of the specimen with crack is reduced and the growth rate of the fatigue crack increases.