Effect of extrusion on microstructure, mechanical properties and corrosion behavior of Mg-5Li-5Al-0.6Y alloy

doi:10.13251/j.issn.0254-6051.2021.08.017

Abstract

Abstract: Mg-5Li-5Al-0.6Y alloy was prepared by casting and hot extrusion. Effect of extrusion on phase and microstructure of the as-cast alloy was studied by means of optical microscopy, scanning electron microscopy and X-ray diffractometer. Effect of extrusion on mechanical properties of the alloy was studied via tensile testing at room temperature and fracture morphology analysis before and after extrusoin. Effect of extrusion on corrosion behavior of the alloy was analyzed by means of hydrogen evolution, mass loss, potentiodynamic polarization curve and electrochemical impedance spectroscopy (EIS). The results indicate that extrusion refines the grain of the Mg-5Li-5Al-0.6Y alloy and the second phases are broken into finer and dispersed particles along the extrusion direction in the α-Mg matrix. Extrusion improves the ultimate tensile strength and elongation of the Mg-5Li-5Al-0.6Y alloy to 243.33 MPa and 7.31%, respectively. Extrusion declines the corrosion rate (calculated from mass loss) of the Mg-5Li-5Al-0.6Y alloy from 17.60 mm·y^-1 to 8.41 mm·y^-1, improving the corrosion resistance of the alloy.

Key words: Mg-5Li-5Al-0.6Y alloy, extrusion, microstructure, mechanical properties, corrosion behavior

CLC Number:

TG146.2⁺2

Ye Jiayu, Feng Yan, He Yuqing, Yang Liuzhong. Effect of extrusion on microstructure, mechanical properties and corrosion behavior of Mg-5Li-5Al-0.6Y alloy[J]. Heat Treatment of Metals, 2021, 46(8): 85-91.

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