Fracture toughness of structural aluminum alloy plates

Abstract

The valid J_Id value is measurable using deeply notched Charpy specimens. The value of 7N01 alloy depends on the heat treatment condition. Over aging results in the high value. The peak aged and 2-step aged 7N01 and 2017 alloys have rather low level of the toughness value. The apparent J_d is affected by the notch root radious and by the microstructure. UPE values obtained in the tear test have a good correlation with the fracture toughness K_Id. The fracture propagation resistance (R-curve) corresponds to the dynamic fracture toughness value. The rank of toughness is in the order of 5083, 7N01 and 2017. Use of the 1/2" thick static three-point bend specimen never permits the valid K_Ic value.