Microstructure and deformation behaviors of two Mg–Li dual-phase alloys with an increasing tensile speed. (15th January 2016)

• Record Type: Journal Article
• Authors: Hanwu, Dong; Limin, Wang; Ke, Liu; Lidong, Wang; Bin, Jiang; Fusheng, Pan
• Is Part Of: Materials & design. Volume 90(2016)
• Page Start: 157
• Page End: 164
• Publication Date: 2016-01-15
• Subjects: Mg–Li alloy -- Dual phase -- Tensile speed -- Serrated effect -- Slip; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2015.10.111
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: Two duplex Mg–Li alloys, Mg–8.02Li–0.210Y and Mg–8.43Li–0.353Ymm (Y-rich mischmetal) alloys, were prepared by casting method with a permanent metal model. Microstructures, mechanical properties and deformation behaviors at tensile rates from 1.28 × 10 − 4 s − 1 to 1.28 × 10 − 3 s − 1 were evaluated. The results showed that when increasing the tensile speed, the strength increased with a decreasing elongation. The strength and ductility of Mg–8.02Li–0.210Y alloy were more sensitive to the tensile speed. Fracture occurred mainly in the β-Li phase, and the α-Mg phase participated into fracture at relatively high tensile speeds, which led to the strength increase of both alloys with the increment of tensile speed. Long-stripe-like α-Mg grains in Mg–8.02Li–0.210Y alloy hindered the fracture and resulted in a higher elongation. Mg–8.02Li–0.210Y alloy presented a serrated effect at a relatively high initial rate of 1.28 × 10 − 3 s − 1 . This was proposed to be resulted from the interaction between slips and α-Mg grains, which was quite different from the serrated effect explained by the dynamic strain aging (DSA) mechanism. Graphical abstract: Highlights: Mechanical properties of Mg–8.02Li–0.210Y alloy were more sensitive to the tensile speed. Fracture occurred mainly in β-Li phase. Long-stripe-like α-Mg grains hindered the fracture and led to higher elongations. Serrated effect in Mg–8.02Li–0.210Y alloy related to slips and α-Mg grains