Effect of microalloying with Ca on the microstructure and mechanical properties of Mg-6 mass%Zn alloys. (15th May 2016)

• Record Type: Journal Article
• Authors: Du, Y.Z.; Qiao, X.G.; Zheng, M.Y.; Wang, D.B.; Wu, K.; Golovin, I.S.
• Is Part Of: Materials & design. Volume 98(2016)
• Page Start: 285
• Page End: 293
• Publication Date: 2016-05-15
• Subjects: Mg-Zn-Ca alloy -- Microalloying -- Microstructure -- Precipitates -- Mechanical properties; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2016.03.025
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: The Mg-6 mass%Zn alloys microalloyed with different amounts of Ca were cast and extruded. The second phase in the as-cast Mg-6Zn alloy is Mg4 Zn7, which is replaced by Ca2 Mg6 Zn3 with an increase of Ca addition. Microalloying by Ca affects the grain size, dynamic recrystallization, and dynamic precipitation of Mg-6Zn alloys during extrusion. The Ca addition inhibits dynamic recrystallization and grain growth due to the pinning effect of fine precipitates, giving rise to fine dynamic recrystallized grains. A large amount of precipitates is observed in the Ca containing alloys after extrusion. Ca effectively improves strength of the as-extruded Mg-6Zn alloy, which is mainly attributed to refined dynamic recrystallized grains, dense precipitates, and deformed regions with high-density dislocations and strong basal texture. Graphical abstract: Highlights: The divorced Mg4 Zn7 in the as-cast Mg-6Zn alloy was replaced by lamellar Ca2 Mg6 Zn3 with increasing Ca addition. Ca addition refined the microstructure, promoted dynamic precipitation and inhibited dynamic recrystallization. Ca addition improved strength of Mg-6Zn alloys, attributed to fine grains, high density precipitates and strong texture.