Designing a Mixed Texture in Mg/Mg Laminated Composite via Bimetal Co-Extrusion to Ameliorate the Mechanical Anisotropy

Abstract

Room-temperature (RT) mechanical anisotropy limits the broad applications of wrought magnesium (Mg) alloys. To weaken the anisotropy, here, we proposed a design idea to create a mixed texture. In the present study, we successfully fabricated the Mg-3Y/Mg-5Li (W3/L5, wt.%) laminated composite, having a mixed texture with a closely orthotropic shape, consisting of an ED-split component in the W3 layer and a TD-split in the L5 layer, via bimetal co-extrusion (ED and TD represent the extrusion and transverse directions, respectively). The mechanical results show that the W3/L5 laminated composite demonstrates a better isotropy at RT, indicating that forming a mixed texture is an effective method to reduce the anisotropy of wrought Mg alloys by bimetal co-extrusion. However, extremely poor interface shear strength, induced by rich O element voids on the interface, triggered poor interface bonding, leading to worse ultimate strength and elongation -to-failure. In future works, controlling co-extrusion parameters or implementing a suitable heat-treatment after extrusion will be necessary to further ameliorate the mechanical properties of the Mg/Mg laminated composites with mixed texture.