Effect of Homogenization Process on Hot Rolling of Aluminum-Lithium Alloys

Aluminum-Lithium alloys are attractive choices for weight saving of aerospace structures. By addition of Lithium to Aluminum alloys, the mechanical and physical properties are improved, density decreases up to 10% and module of elasticity increases up to 15%. As-cast Al-Li ingots include some continues brittle phases in grain boundaries that decrease formability by crack initiation during hot rolling. In the present work, influence of homogenization on hot rolling of Al- Li alloys was studied. Homogenization temperature determined based on DTA test and homogeneity properties were characterized by microstructures observation. One specimen was cast in conventional method and the other was cast by direct casting (DC) method. Homogenization was performed at four different times: 10, 24, 50 and 100 hours at 500ºC also no cracking has been observed in both ingots in 100 hr and 24 hr at 500ºC respectively due to eliminate the brittle phases.