High ductility of a bi-modal Mg-7wt.%Y alloy at low temperature prepared by high pressure boriding and semi-solid extrusion
High ductility of a bi-modal Mg-7wt.%Y alloy at low temperature prepared by high pressure boriding and semi-solid extrusion
复制标题
DOI：
10.1016/j.matdes.2015.12.024
复制
发表时间：
2016-02-15
影响因子：
8.4
通讯作者：
Peng, Qiuming
中科院分区：
文献类型：
--
作者：
Fu, Hui;Li, Hui;Peng, Qiuming
一架双峰Mg-7wt。采用高压渗硼和半固态挤压的新工艺成功制备了%Y合金。在接近170℃的温度下，在应变速率为1 × 10(-3) s（-1）时，显示出超塑性。晶粒尺寸范围从数百纳米到150微米，其中细晶粒在Hall-Petch关系方面具有良好的强度，而粗晶粒由于高的位错储存效率而具有高的延展性。与传统的单一细晶粒或粗晶粒相比，由于存在扩展孪晶、大角度晶界和稳定的高熔点纳米级YB12颗粒，这种双模态结构被证实是提高镁合金变形能力的更有效途径。(C) 2015 Elsevier Ltd.版权所有。
A bi-modal Mg-7wt.%Y alloy has been successfully prepared by a novel route of high pressure boriding and semisolid extrusion. It reveals superplasticity at a temperature of similar to 170 degrees C at the strain rate of 1 x 10(-3) s(-1). The grain size ranges from hundreds nanometer to 150 pm, wherein the fine grains provide good strength in terms of Hall-Petch relationship, while the coarse grains offer high ductility due to high dislocation storage efficiency. Compared with conventional single fine or coarse grains, this bi-modal structure is confirmed as a more effective pathway in promoting the deformability of Mg alloys because of the occurrence of extension twinning, the presence of large angle grain boundaries and stable nano-scale YB12 particles with a high melting point. (C) 2015 Elsevier Ltd. All rights reserved.