Superior elevated-temperature strength of Mg–Y–Sn alloys with thermostable multi-scale precipitates and grain structure
Superior elevated-temperature strength of Mg–Y–Sn alloys with thermostable multi-scale precipitates and grain structure
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DOI：
10.1016/j.msea.2022.143643
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发表时间：
2022-07
期刊：
影响因子：
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通讯作者：
D. Yin;Shupeng Li;K. Sun;Ruihao Fu;Yingbo Zhang;B. Jiang;Y. Huang;Y. Zeng
中科院分区：
文献类型：
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作者：
D. Yin;Shupeng Li;K. Sun;Ruihao Fu;Yingbo Zhang;B. Jiang;Y. Huang;Y. Zeng
通过在Mg-6 Y合金中添加Sn（0.6wt%和1.5wt%）制备了新开发的Mg-Y-Sn合金挤压件。优化后的Mg-6 Y-1.5Sn合金在高达300 °C的高温下表现出优异的上级强度，并表现出明显的应变硬化。具体而言，该合金在300 °C下的屈服应力和极限拉伸强度分别为186 ± 3 MPa和328 ± 7 MPa，分别比高度RE合金化的WE 54高64%和93%。Mg-6 Y中加入Sn后，产生了大量热稳定的微米/纳米级Sn 3 Y 5沉淀。Mg-6 Y-1.5Sn合金中纳米级析出相的数量较多，其高温强度优于Mg-6 Y-0.6Sn合金。Mg-6 Y-0.6/1.5Sn合金的晶粒结构由均匀的等轴晶转变为热稳定的多尺度晶粒结构，由高位错密度的纤维织构非DRX区和低位错密度的随机取向DRX区组成。异常的高温强度强烈相关的组合热稳定的多尺度沉淀物和晶粒结构。
The newly developed Mg–Y–Sn extrusions are prepared by adding Sn (0.6 and 1.5 wt%) to Mg–6Y. The optimized Mg–6Y-1.5Sn exhibited superior elevated-temperature strength up to 300 °C, charactered by the pronounced strain hardening. Specifically, the yield stress and ultimate tensile strength of this alloy at 300 °C are 186 ± 3 MPa and 328 ± 7 MPa, respectively, which are 64% and 93% higher than that of the highly RE-alloyed WE54. Sn addition to Mg–6Y introduces a large number of thermal-stable micron/nano-scale Sn3Y5precipitates. Mg–6Y-1.5Sn, which contained more nano-scale precipitates, exhibited better elevated-temperature strength than that of Mg–6Y-0.6Sn. The grain structure transitioned from a uniformed equiaxial grain in Mg–6Y to a thermal-stable multiscale grain structure in Mg–6Y-0.6/1.5Sn, which consisted of fiber textured un-DRXed area with high dislocation density and randomly orientated DRXed grains with low dislocation density. The exceptional elevated-temperature strength strongly correlated to the combined thermal-stable multiscale precipitates and grain structures.