Strengthening Effect of Extruded Mg-8Sn-2Zn-2Al Alloy: Influence of Micro and Nano-Size Mg₂Sn Precipitates.
Strengthening Effect of Extruded Mg-8Sn-2Zn-2Al Alloy: Influence of Micro and Nano-Size Mg₂Sn Precipitates.
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DOI：
10.3390/ma10070822
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发表时间：
2017-07-18
期刊：
影响因子：
--
通讯作者：
Yu H
中科院分区：
文献类型：
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作者：
Cheng W;Bai Y;Wang L;Wang H;Bian L;Yu H
在这项研究中，通过不同的预处理（无和有T4）获得了挤压前不同Mg2Sn含量的Mg-8Sn-2Zn-2Al（TZA822）合金，并报告了挤压TZA822合金中与微米和纳米尺寸Mg2Sn析出物相关的强化响应。结果表明，由于挤压前微米级颗粒比例的减少，纳米级Mg2Sn析出物的形貌发生了显着的基面变化，从棒状变为球形。同时，球形Mg2Sn析出物比棒状析出物具有更强的强化效果，这归因于球形析出物的均匀分散和细化，有效阻碍了基底位错滑移。因此，与不含 T4 的挤压 TZA822 合金相比，含有 T4 的挤压 TZA822 合金表现出更高的拉伸屈服强度 (TYS)、320 MPa 的极限拉伸强度 (UTS)、320 MPa 的极限拉伸强度 (UTS) 和 26.5% 的延伸率 (EL)，以及更低的屈服不对称度。给出了强化效果的详细原因并进行了分析。
In this study, Mg-8Sn-2Zn-2Al (TZA822) alloys with varying Mg2Sn contents prior to extrusion were obtained by different pre-treatments (without and with T4), and the strengthening response related to micro and nano-size Mg2Sn precipitates in the extruded TZA822 alloys was reported. The results showed that the morphology of nano-size Mg2Sn precipitates exhibits a significant change in basal plane from rod-like to spherical, owing to the decrement in the fraction of micro-size particles before extrusion. Meanwhile, the spherical Mg2Sn precipitates provided a much stronger strengthening effect than did the rod-like ones, which was ascribed to uniform dispersion and refinement of spherical precipitates to effectively hinder basal dislocation slip. As a consequence, the extruded TZA822 alloy with T4 showed a higher tensile yield strength (TYS) of 245 MPa, ultimate tensile strength (UTS) of 320 MPa and elongation (EL) of 26.5%, as well as a lower degree of yield asymmetry than their counterpart without T4. Detailed reasons for the strengthening effect were given and analyzed.