Investigation of Mechanical Properties, Formability, and Anisotropy of Dual Phase Mg-7Li-1Zn

Abstract

In this article, the mechanical properties, microstructure, forming limit diagram (FLD) and anisotropy of dual phase Mg-7Li-1Zn alloy have been evaluated by a uniaxial tensile test at three directions, scanning electron microscopy (SEM), optical microscopy (OM) and hemispherical punch test at ambient temperature. The optical microscopy images showed that the microstructure of as-cast LZ71 alloy possesses a dual phase microstructure such as β-Li matrix with bodycentered cubic (BCC) structure and a partitioned α-Mg phase with hexagonal closest packed (HCP) structure in lath shape. After rolling process, the α-Mg phase has been elongated and arranged in the rolling direction and anisotropy at different directions increased, but after full annealing, microstructure arranged more uniform and changed from elongated to the uniform structure which this is the factor that reflects the reduction of anisotropy. FLD shows the limiting surface strains that sheet metal can endure before the start of localized necking and fracture at different deformation modes in tension-tension and tension-compression loading paths. The FLD of Mg-7Li-1Zn showed that this material has desirable formability due to the BCC structure with high slip system in the ambient temperature. Also, the results of the tensile test matched with the Preprint of: Davood Rahmatabadi, Ramin Hashemi, Moslem tayyebi and Abbas Bayati. (2019). Investigation of mechanical properties, formability, and anisotropy of dual phase Mg-7Li-1Zn. Materials Research Express.

A method and apparatus for determination of the ultrasonic-assisted forming limit diagram

“…The XRD data were then analyzed using the Williamson-Hall formula and X'Pert High Score software. 33 Lastly, the average crystallite size of specimens has been calculated for each peak separately.…”