Effect of heat treatment on microstructure and mechanical properties of extruded ZM61 magnesium alloy
Effect of heat treatment on microstructure and mechanical properties of extruded ZM61 magnesium alloy
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DOI：
10.1179/1743284712y.0000000095
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发表时间：
2012-12
影响因子：
1.8
通讯作者：
F. Qi;D. F. Zhang;Z. Zhu;X. Xu;G. Shi
中科院分区：
文献类型：
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作者：
F. Qi;D. F. Zhang;Z. Zhu;X. Xu;G. Shi
研究了T5和T6热处理对挤压态Mg-6 Zn-1 Mn合金显微组织和力学性能的影响。结果表明，T5和T6处理能显著提高挤压态ZM 61合金的强度，双级时效的析出强化效果优于单级时效。与T5处理相比，T6处理的析出相更细小、更弥散，具有更强的沉淀强化作用。然而，由于额外的晶粒尺寸细化强化效果，T5处理可以改善延展性而不牺牲强度超过T6处理。扫描电镜观察和拉伸试验表明，挤压后不同的冷却方式（空冷和水淬）对挤压态和热处理态Mg-6 Zn-1 Mn合金的组织和强度没有明显影响。此外，Mn元素主要以细小的Mn相颗粒存在，在基体中弥散分布。在棒状沉淀物中可以发现分散的Mn颗粒，而在盘状沉淀物中没有发现。
Abstract The effects of T5 and T6 heat treatments on the microstructure and mechanical properties of extruded Mg–6Zn–1M n alloy were investigated in the present study. The results showed that T5 and T6 treatments could markedly improve the strengths of extruded ZM61 alloy, and the precipitate strengthening effect of double aging was better than that of single aging. The precipitates formed in the T6 treatment were much finer and more dispersive than the ones in the T5 treatment, resulting in stronger precipitation strengthening effect. However, due to additional grain size refinement strengthening effect, the T5 treatment could improve ductility without sacrificing strength over the T6 treatment. Scanning electron microscopy observation and tensile test indicated that different cooling methods after extrusion, such as air cooling and water quenching, had no obvious influence on the microstructure and strengths of extruded and subsequent heat treated Mg–6Zn–1Mn alloys. In addition, the Mn element mainly existed as fine Mn phase particles, which were well dispersed in the matrix. Dispersed Mn particles could be found in rod-like precipitates, but not in the disc shaped precipitates.