Liu Kun, Zhao Sicong, Wang Changliang, Wang Liping, Feng Yicheng, Liu Dongrong, Li Jingfang, Wang Zhiwei
Key Laboratory of Advanced Manufacturing and Intelligent Technology (MOE), School of Material Science and Chemical Engineering, Harbin University of Science and Technology, Harbin 150080, China.
Key Laboratory of Functional Inorganic Material Chemistry (MOE), School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080, China.
Materials (Basel). 2021 Sep 29;14(19):5667. doi: 10.3390/ma14195667.
Achieving magnesium-rare earth alloys with excellent mechanical properties remains a challenging goal in the aerospace industry. The integrated extrusion and equal channel angular pressing were employed to refine grain and improve the mechanical properties of Mg-xNd-2.0Sm-0.4Zn-0.4Zr alloys. The effect of Nd element on microstructure and mechanical properties of the extruded and subsequently aged alloys were carried out by varying the amount of the Nd element from 0 wt.% to 2.5 wt.%. The optical microscopy results indicated that the grain size was remarkably refined by the addition of Nd element. The grain size decreased from 29.7 μm to 10.9 μm with increasing of the Nd element from 0 wt.% to 2.5 wt.%. The transmission electron microscopy results showed that the nano-scaled basal lamellar precipitates, prismatic lamellar precipitates and granular precipitates were formed in α-Mg matrix. The amount of the precipitates increased significantly by the addition of Nd. Moreover, the strength of the alloys significantly improved with Nd. Superior strength and considerable plasticity were obtained as the content of Nd element reached 2.0 wt.%, while the tensile strength of the Mg-2.0Nd-Sm-Zn-Zr alloy (315 ± 5 MPa) increased by 35.8% with respect to the Nd-free alloy (232 ± 3 MPa).
在航空航天工业中，获得具有优异力学性能的镁稀土合金仍然是一个具有挑战性的目标。采用综合挤压和等通道转角挤压工艺细化晶粒并改善Mg-xNd-2.0Sm-0.4Zn-0.4Zr合金的力学性能。通过将Nd元素的含量从0 wt.% 变化到2.5 wt.%，研究了Nd元素对挤压及随后时效合金的微观结构和力学性能的影响。光学显微镜结果表明，添加Nd元素可显著细化晶粒。随着Nd元素含量从0 wt.% 增加到2.5 wt.%，晶粒尺寸从29.7μm减小到10.9μm。透射电子显微镜结果表明，在α-Mg基体中形成了纳米级的基面片状析出物、棱柱片状析出物和颗粒状析出物。添加Nd后析出物的数量显著增加。此外，合金的强度随着Nd的添加而显著提高。当Nd元素含量达到2.0 wt.%时，获得了优异的强度和可观的塑性，Mg-2.0Nd-Sm-Zn-Zr合金的抗拉强度（315±5 MPa）相对于无Nd合金（232±3 MPa）提高了35.8%。
