Comparison of Aluminum Alloy 7050, 7049, MA52, and 7175-T736 Die Forgings

Die forgings in aluminum alloys 7050, 7049, and MA52 were fabricated and evaluated for resistance to stress-corrosion cracking, quench sensitivity, and fracture toughness. In addition, all Alcoa data on 7050, 7049, and special process 7175-T7X die forgings were examined and the properties were collated. Stress-corrosion resistances were evaluated using the severest combinations of forging type and test conditions. All of these newer alloys were less quench sensitive than alloy 7075, and all developed better combinations of resistance to stress-corrosion cracking and fracture toughness than 7075-T6 and 7079-T6 at equal strengths. Because it developed the best combination of properties, alloy 7050 is a preferred selection for use as die forgings of relatively heavy section thickness for the aerospace industry. This alloy also can be supplied as hand forgings, plate, extrusions, and sheet. Special process 7175 is an equally good selection for die forgings of thin to moderate section thickness.