Al-Cu Atomic Percent Copper 10 20 30 40 50 60 70 80 90 100 1100- 1084 87 L 900 800 Temperature c 700 800,452"C 1 600 B A 5482"c 5004 3 4 C 400 (AD) (cu) 300 10 20 30 40 50 60 70 BO 90 100 Al Weight Percent Copper Cu Line Names Phases Present in Phase Fields A 4