Development of dilute Mg-Zn-Ca-Mn alloy with high performance via extrusion

Dilute Mg-0.21Zn-0.30Ca-0.14Mn (wt.%) alloy was newly developed as low-cost wrought Mg alloy. Excellent balance of strength and ductility was achieved via extrusion process by grain refinement and texture modification. The dilute alloy extruded at 300 degrees C exhibited a tensile yield strength of 307 MPa and an elongation of 20.6% due to a bimodal microstructure consisting of fine dynamically recrystallized (DRXed) grains of similar to 2.3 mm and strongly textured coarse unDRXed grains. After extrusion at 350 degrees C, almost fully DRXed microstructure (DRX fraction of similar to 0.96) and significantly weakened basal texture (maximum intensity of 3.2) with rare-earth texture component were achieved, consequently resulting in a high compression/tension yield ratio of similar to 0.8 with tensile elongation of 30.0% and tensile yield strength of 164 MPa. Besides, fine spherical Mg2Ca and alpha-Mn phases dynamically precipitated during extrusion, acting as effective pinning obstacles against the DRXed grain growth. (C) 2016 Elsevier B.V. All rights reserved.