Improved strength in wrought Mg–Y–Ni alloys by adjusting the block-shaped LPSO phase and plate-shaped γ′ phase-猫眼课题宝

通过调整块状 LPSO 相和板状 γ-2 相提高变形 Mg-Y-Ni 合金的强度

DOI：

10.1016/j.msea.2021.142198

发表时间：

2021-10

期刊：

Materials Science & Engineering A

影响因子：

通讯作者：

中科院分区：

其他

文献类型：

作者：

S.Z. Wu;X.G. Qiao;S.H. Qin;Y.Q. Chi;M.Y. Zheng

研究了两种具有不同块状LPSO相体积分数和不同板状γ′相数量密度的Mg-Y-Ni合金的显微组织和力学性能。在Y/Ni原子比为1的Mg-Y-Ni合金中，块状LPSO相的体积分数随着Y和Ni含量的增加而增加。铸态合金在挤压前预热时，在基体中形成板状γ′相，并沿基体生长，其数量密度随Y和Ni含量的增加而增大。挤压后，块状的LPSO相沿挤压方向分布，具有强基底织构的非动态再结晶（non-DRXed）晶粒和具有随机织构的动态再结晶（DRXed）晶粒中均存在板状的γ′相。随着LPSO相体积分数的增加，挤压态Mg-Y-Ni合金的抗拉屈服强度提高，但塑性降低。除了LPSO相具有明显的强化作用外，片状γ′相也是一种有效的强化相，它可以阻碍Mg-Y-Ni合金非DRXed和DRXed晶粒中滑移体系的移动。含有块状LPSO相体积分数最高和板状γ′相数量密度最高的Mg94Y3Ni3 （at%）合金挤压后的抗拉屈服强度达到502 MPa。

The microstructure and mechanical properties of two Mg–Y–Ni alloys with different volume fraction of block-shaped LPSO phase and different number densities of plate-shaped γ′ phase were investigated. The volume fraction of block-shaped LPSO phase increases with the content of Y and Ni in the Mg–Y–Ni alloys with Y/Ni atomic ratio of 1. The plate-shaped γ′ phase is formed in the matrix of the as-cast alloys and grows across the matrix during the preheating before extrusion, and its number density increases with increasing content of Y and Ni. After extrusion, the block-shaped LPSO phase is distributed along extrusion direction, and the plate-shaped γ′ phase can be observed in both non-dynamic recrystallized (non-DRXed) grains with strong basal texture and dynamic recrystallized (DRXed) grains with random texture. The increased volume fraction of LPSO phase improves the tensile yield strength of the as-extruded Mg–Y–Ni alloys, accompanied by the decrease in ductility. In addition to the obvious strengthening from the LPSO phase, the plate-shaped γ′ phase is also an effective strengthening phase which can hinder the movement of the slip systems in non-DRXed and DRXed grains of the Mg–Y–Ni alloys. The Mg94Y3Ni3 (at%) alloy containing the highest volume fraction of block-shaped LPSO phase and the highest number density of plate-shaped γ′ phase exhibits the superior tensile yield strength of 502 MPa after extrusion.