Modification of Microstructure and Mechanical Properties of Extruded AZ91-0.4Ce Magnesium Alloy through Addition of Ca

• Published in: Materials 2024-07, Vol.17 (13), p.3359
• Main Authors: Ni, Fengtao, Peng, Jian, Liu, Xiangquan, Gao, Pan, Nie, Zhongkui, Hu, Jie, Zhao, Dong
• Format: Article
• Language: English
• Subjects: Alloying elements; Deformation; Dynamic recrystallization; Electron microscopy; Extrusion; Grain boundaries; Grain refinement; Grain size; Low carbon steel; Magnesium alloys; Magnesium base alloys; Mechanical properties; Microstructure; Rare earth elements; Scientific imaging; Tensile tests; Ultimate tensile strength; Yield strength
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma17133359

The effect of the addition of alkali earth element Ca on the microstructure and mechanical properties of extruded AZ91-0.4Ce-xCa (x = 0, 0.4, 0.8, 1.2 wt.%) alloys was studied by using scanning electron microscopy, transmission electron microscopy, and tensile tests. The results showed that the addition of Ca could significantly refine the second phase and grain size of the extruded AZ91-0.4Ce alloy. The refinement effect was most obvious when 0.8 wt.% of Ca was added, and the recrystallized grain size was 4.75 μm after extrusion. The addition of Ca resulted in the formation of a spherical Al Ca phase, which effectively suppressed the precipitation of the β-Mg Al phase, promoted dynamic recrystallization and grain refinement, impeded dislocation motion, and exerted a positive influence on the mechanical properties of the alloy. The yield strength (YS), ultimate tensile strength (UTS), and elongation (EL) of the AZ91-0.4Ce-0.8Ca alloy were 238.7 MPa, 338.3 MPa, and 10.8%, respectively.