Microstructure and mechanical properties of Mg–6Li–xAl–0.8Sn alloys

ABSTRACT

As-cast and as-extruded Mg–6Li–xAl–0.8Sn (x = 0, 1, 3 and 5 wt-%) alloys were prepared. The microstructure and mechanical properties were investigated and discussed. The experimental results show that the Mg–6Li–0.8Sn alloy is composed of three phases: α-Mg, Mg₂Sn and Li₂MgSn. With the addition of Al, the test alloys display typical α-Mg + β-Li duplex structures. The new Mg₁₇Al₁₂ and LiMgAl₂ phases were found in the Mg–6Li–1Al–0.8Sn alloy. The lamellar-type AlLi phase was formed whereas the Mg₁₇Al₁₂ phase disappeared in Mg–6Li–3Al–0.8Sn alloy. The LiMgAl₂ phase vanished in the Mg–6Li–5Al–0.8Sn alloy. The mechanical properties of as-extruded alloys were remarkably improved. The as-extruded Mg–6Li–3Al–0.8Sn alloy exhibited the best mechanical properties, with a yield strength, tensile strength and elongation of 209.8 MPa, 242.6 MPa and 15.5%, respectively.

KEYWORDS:

• Mg–Li alloy
• hot extrusion
• microstructure
• mechanical properties

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Lina Ma http://orcid.org/0000-0002-8542-830X

Yan Yang http://orcid.org/0000-0002-0128-2172

Hongyan Shao http://orcid.org/0000-0002-0078-922X

Additional information

Funding

The authors would like to acknowledge financial support by the National Key Research and Development Program of China (Project No. 2016YFB0700403), the National Natural Science Foundation (Project No. 51601024), the Chongqing Research Program of Basic Research and Frontier Technology (Project No. cstc2016jcyjA0418) and the Fundamental Research Funds for the Central Universities (Project No. 2018CDJDCL0019 & Project No. 2018CDJDCL0020).