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

Conclusions

• 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 K ^y_c 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/mm^3/2.

  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.