Influence of hetero-duplex structure on mechanical properties of Mg–Al/Cu–Zn alloys

Hetero-duplex structure containing both structural and spatial heterogeneities has been developed in a series of Mg–Al/Cu–Zn alloys. Among these alloys, a hetero-duplex Mg72Cu5Zn23 alloy with uniform dispersion of spherical duplex colonies exhibits high yield strength of 455 MPa with a plasticity of ∼5%. On the contrary, a hetero-duplex Mg70Al3Zn22 alloy consisting of typical polygonal duplex colonies undergoes catastrophic failure without macroscopic plasticity. Based on these results, it is possible to consider that the morphology of the hetero-duplex colony plays an important role to control the macroscopic plasticity of the hetero-duplex alloys.