Effects of Al and Y Addition on Microstructures and Mechanical Properties of As‐Cast Mg–14Li Based Alloy. Issue 2 (2nd November 2018)

• Record Type: Journal Article
• Authors: Gao, Zhankui; Liu, Wencai; Wu, Guohua; Zhang, Liang; Ji, Hao; Ouyang, Sijie; Peng, Xiang; Xiao, Lv; Ding, Wenjiang
• Is Part Of: Advanced engineering materials. Volume 21:Issue 2(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-11-02
• Subjects: mechanical properties -- Mg–Li–Al–Y alloy -- microstructure -- single β–Li; Materials -- Periodicals; 620.11
• DOI: 10.1002/adem.201800755
• Languages: English
• ISSNs: 1438-1656

Abstract

Abstract : In this study, effects of Al and Y contents on microstructural evolutions and mechanical properties of the as‐cast Mg–14Li alloy are investigated. The results show that Mg–14Li– x Al ( x = 1, 2, 3 wt%) alloys are characterized by predominantly single β –Li and MgLiAl2 phases. Slight refinement of β –Li grains is obtained with the increasing of Al content. The increased Al addition greatly improves the hardness, ultimate tensile strength, and yield strength of the Mg‐14 base alloy, accompanied by a significant reduction in ductility. Meanwhile, with addition of minor Y (0.5 wt%) addition leads to the introduction of homogeneous distribution of Al2 Y particles in the Mg–14Li–3Al alloy, which plays a positive role in the strength enhancement. However, the uneven distribution of apparently coarsed Al2 Y particles contributes to a significant reduction in tensile strength as the Y content is increased up to 1 wt%. Abstract : In the alloy of Mg–14Li–3Al–0.5Y, β –Li phases are dramatically spheroidized after addition of surface‐active element Y. Round‐like Al2 Y phases locate along grain boundaries. And considerable secondary crack sources initiate both at grain interiors and along grain boundaries and propagate with a combination of inter‐granular and trans‐granular way.