TY - JOUR
T1 - Microstructure and mechanical properties of as-cast ultralight and high strength Mg-10Li-3Al-3Zn-xY alloy with multi-precipitates
AU - Song, Wenjie
AU - Liu, Jie
AU - He, Shuai
AU - Shen, Jianghua
AU - Yang, Guang
AU - Liu, Yanhui
AU - Chen, Youxing
AU - Wei, Qiuming
N1 - Publisher Copyright:
© 2022
PY - 2022/7
Y1 - 2022/7
N2 - Magnesium‑lithium (Mg–Li) alloys have been widely used in various engineering fields due to their ultra-light characteristics. The strengthening of Mg–Li alloys is one of the key factors determining its application and has received extensive attention. In this work, the as-cast ultralight and high strength Mg-10Li-3Al-3Zn-xY (x = 0, 0.5 and 1.0, wt%) alloys with a density of only 1.52 g/cm3 were prepared via vacuum induction melting. The effects of rare earth element yttrium (Y) on the microstructure and mechanical properties of the Mg–Li alloy system were investigated. The results indicated that the microstructures of all the alloys mainly consisted of α-Mg, β-Li, AlLi, and MgLi2Al phases. The spherical AlLi phase was distributed inside the α-Mg and β-Li matrix. Part of the petal-like MgLi2Al phase was distributed in the interior of β-Li, and the rest grew along the grain boundaries as long strips. With the addition of Y, Al2Y phase formed with sharp edges and regular shapes. The Al2Y phase was mainly distributed inside the α-Mg phase and along the grain boundaries. Meanwhile, the amount of AlLi phase inside the α-Mg phase gradually decreased. The presence of nano-scale lath-shape MgLiZn phase in the β-Li matrix was observed in the HAADF map of the 0.5Y alloy. The continuous growth of MgLi2Al phase at the grain boundaries weakened its strength. As a consequence, it eventually led to intergranular fracture of the alloy. The 0.5Y alloy showed the highest tensile strength, up to ~244 MPa, and the yield strength was 60.5% higher than that of the 0Y alloy. Solid solution strengthening, precipitate strengthening and grain refinement were thus considered as the primary strengthening mechanisms caused by the addition of Y into the Mg-10Li-3Al-3Zn alloy.
AB - Magnesium‑lithium (Mg–Li) alloys have been widely used in various engineering fields due to their ultra-light characteristics. The strengthening of Mg–Li alloys is one of the key factors determining its application and has received extensive attention. In this work, the as-cast ultralight and high strength Mg-10Li-3Al-3Zn-xY (x = 0, 0.5 and 1.0, wt%) alloys with a density of only 1.52 g/cm3 were prepared via vacuum induction melting. The effects of rare earth element yttrium (Y) on the microstructure and mechanical properties of the Mg–Li alloy system were investigated. The results indicated that the microstructures of all the alloys mainly consisted of α-Mg, β-Li, AlLi, and MgLi2Al phases. The spherical AlLi phase was distributed inside the α-Mg and β-Li matrix. Part of the petal-like MgLi2Al phase was distributed in the interior of β-Li, and the rest grew along the grain boundaries as long strips. With the addition of Y, Al2Y phase formed with sharp edges and regular shapes. The Al2Y phase was mainly distributed inside the α-Mg phase and along the grain boundaries. Meanwhile, the amount of AlLi phase inside the α-Mg phase gradually decreased. The presence of nano-scale lath-shape MgLiZn phase in the β-Li matrix was observed in the HAADF map of the 0.5Y alloy. The continuous growth of MgLi2Al phase at the grain boundaries weakened its strength. As a consequence, it eventually led to intergranular fracture of the alloy. The 0.5Y alloy showed the highest tensile strength, up to ~244 MPa, and the yield strength was 60.5% higher than that of the 0Y alloy. Solid solution strengthening, precipitate strengthening and grain refinement were thus considered as the primary strengthening mechanisms caused by the addition of Y into the Mg-10Li-3Al-3Zn alloy.
KW - As-cast Mg–Li alloy
KW - HAADF images
KW - Mechanical properties
KW - Microstructure
KW - Second phases
KW - Yttrium
UR - http://www.scopus.com/inward/record.url?scp=85130519668&partnerID=8YFLogxK
U2 - 10.1016/j.matchar.2022.111972
DO - 10.1016/j.matchar.2022.111972
M3 - 文章
AN - SCOPUS:85130519668
SN - 1044-5803
VL - 189
JO - Materials Characterization
JF - Materials Characterization
M1 - 111972
ER -