Microstructure and mechanical properties of extruded Mg-Y-Zn (Ni) alloys
Microstructure and mechanical properties of extruded Mg-Y-Zn (Ni) alloys
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DOI：
10.1016/j.jallcom.2021.160577
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发表时间：
2021-06-02
影响因子：
6.2
通讯作者：
Ma, Ying
中科院分区：
文献类型：
--
作者：
Bi, Guang Li;Wang, Yashuo;Ma, Ying
系统研究了挤压态Mg-2 Y-1 Zn（MYZ）、Mg-2 Y-0.5Zn-0.5Ni（MYZN）和Mg-2 Y-1 Ni（MYN）（at%）合金的显微组织和力学性能。除α-Mg、Mg_2 Y、Mg_（24）Y_5、沿着富Y相外，在上述3种铸态合金中，α-Mg枝晶晶界处均析出了18 R LPSO相，其形貌为粗片层。在均匀化过程中，部分18 R LPSO相转变为14 H LPSO相。挤压后，晶粒明显细化，在3种挤压态合金中均存在3种形貌的LPSO相，沿挤压方向（艾德）均存在片层状18 R LPSO相、块状18 R LPSO相和细小条状14 H LPSO相，且晶粒内部存在层错。挤压态MYZN合金的织构强度高于挤压态MYZ和MYN合金。此外，我们还讨论了不同形貌的LPSO相的强化机制。拉伸试验结果表明，挤压态MYZN合金在室温下具有最高的σ UTS为389 MPa，σ TYS为336 MPa，σ Δ f为12.6%。挤压态MYZN合金综合力学性能的提高主要与LPSO相强化、织构强化、层错强化和晶粒细化有关。(C)2021爱思唯尔有限公司版权所有。
The microstructure and mechanical properties of extruded Mg-2Y-1Zn (MYZ), Mg-2Y-0.5Zn-0.5Ni (MYZN) and Mg-2Y-1Ni (MYN) (at%) alloys were systematically investigated. Apart from alpha-Mg, Mg2Y, Mg24Y5, along with Yriched phases, there was precipitation of 18R LPSO phase with coarse-lamellar morphology at the dendritic grain boundary of alpha-Mg within the above three as-cast alloys. Parts of 18R LPSO phases transformed into 14H LPSO phases in homogenization. After extrusion, the grain size had obviously refined and the LPSO phase with three types of morphologies existed in three extruded alloys, distribution of lamellar 18R LPSO phase might be detected down the extrusion direction (ED), the blocky 18R LPSO phase as well as the fine strip 14H LPSO phase with some stacking faults in the grain interior. The extruded MYZN alloy exhibited the higher basal texture intensity than extruded MYZ and MYN alloys. Furthermore, we discussed the strengthening mechanisms of the LPSO phase with different morphologies. Tensile test results indicated that the as-extruded MYZN alloy exhibited the highest sigma UTS of 389 MPa, sigma TYS of 336 MPa and epsilon f of 12.6% at room temperature. As for the extruded MYZN alloy, its improved comprehensive mechanical properties were mainly related to the LPSO phase strengthening, texture strengthening, stacking faults strengthening together with grain refinement. (C) 2021 Elsevier B.V. All rights reserved.