Investigation of microstructure and mechanical properties of ZK60 magnesium alloy achieved by extrusion-shearing process

The microstructure characterization, mechanical properties and texture evolution of a ZK60 alloy achieved via the extrusion-shearing (ES) process were systematically studied with the help of optical microscopy (OM), X-ray diffractometry (XRD), scanning electron microscope (SEM) and electron back-scattered diffraction (EBSD). The results showed that the grain size was refined to similar to 1.7 mu m and the microstructure became more uniform. The tensile yield strength and ultimate tensile strength at room temperature of the ES-processed alloy reached 263 MPa and 321 MPa, respectively, which were 35.6% and 10.7% higher than that of the as-annealed alloy. Grain refinement, precipitate strengthening, and dislocation strengthening are the main factors for the improvement in strength. After the ES process, the elongation of ZK60 alloy increased from 16.6% to 23.7%, which is attributed to the activation of the basal slip system and texture modification. Moreover, the tension-compression yield asymmetry of the ZK60 alloy was significantly improved after extrusion, thus indicating that the extrusion-shearing process suggested in this work has great potential for the large-scale application of magnesium alloys. (c) 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

The microstructure, mechanical properties, and texture evolution of the ZK60 alloy were investigated after processing via the extrusion-shearing (ES) method. The alloy exhibited refined grain size, uniform microstructure, improved strength, and increased elongation. The extrusion-shearing process has great potential for the large-scale application of magnesium alloys.