Rotation friction extrusion process towards high-performance Mg-Li matrix composites enhanced by FeCoNiCrCu high entropy alloy

To pursue wide applications of Mg-Li alloys in aerospace field, bringing in reinforcement phases reasonably and manufacturing efficiently have become paramount. Herein, a novel rotation friction extrusion process was proposed to fabricate FeCoNiCrCu high entropy alloy reinforced Mg-Li matrix composites, which were enhanced by newly formed nano-sized AlCuMg phase particles. The grain size of Mg-Li matrix composites was 4.19 μm. Meanwhile, a 69.03 nm thickness amorphous layer was obtained, which was composed of amorphous and nanocrystalline structure. The maximum tensile strength reached 201.3 MPa, which was improved by 43.9 % compared with LAZ933 Mg-Li alloy. It can be attributed to fine grain strengthening and dispersion strengthening, which resulted from dynamic recrystallization in Mg-Li alloy and Cu segregation from the interior of high entropy alloy. This work shows a novel processing and original reinforcement phase, providing a peculiar way to fabricate Mg-Li matrix composites.