Abstract
Eight Al-Zn-Mg-Cu-Mn alloy forgings were made with different compositions within the DTD 5024 specification limits, to study the effect of variations in content on the plane-strain fracture toughness and on the tensile properties. In three of the forgings the iron content alone was varied and it was found that iron was detrimental to the fracture toughness. A systematic variation in the magnesium content of three further alloys indicated that the alloy with the lowest magnesium content of 2.2% had the highest fracture toughness and proof strength. A low zinc content of 5.2% gave a high fracture toughness but this was at the expense of the proof strength. It was discovered that a relationship existed between the fracture toughness of the alloys and their tensile behaviour expressed in true stress/true strain terms.
Get full access to this article
View all access options for this article.