Combination effects of Yb addition and cryogenic-rolling on microstructure and mechanical properties of LA141 alloy

Abstract Microstructure and mechanical properties of cryogenic-rolled LA141-xYb (x = 0, 0.1) alloys were investigated. With the addition of Yb, the grains of the alloy are refined, and some fine Al3Yb phases are formed. The submicron scale dynamic recrystallized grains can be observed in the cryogenic rolled specimen. The addition of Yb inhibits the dynamic recrystallization and refines the grains during cryogenic rolling. As a result, the work softening is greatly reduced, and the strength is significantly increased. The results show that, due to the addition of Yb, the ultimate tensile strength of as-cast and CR-processed alloys is increased by 14.5% and 40.1%, respectively, reaching 197 MPa and 241 MPa. It is mainly caused by the combined effects of refinement, dispersive fine Al3Yb particles, high density dislocation and stack faults (SFs).