Effect of rare-earth element additions on high-temperature mechanical properties of AZ91 magnesium alloy
Effect of rare-earth element additions on high-temperature mechanical properties of AZ91 magnesium alloy
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DOI：
10.1007/s11661-005-0022-6
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发表时间：
2005-12-01
影响因子：
2.8
通讯作者：
Khoshkhooei, S
中科院分区：
文献类型：
--
作者：
Khomamizadeh, F;Nami, B;Khoshkhooei, S
本文重点研究镁合金AZ91的高温力学性能。添加高达 2 Wt% 的稀土 (RE) 元素，通过用含 RE 金属间化合物代替 Mg17Al12 相，提高了 140 摄氏度下的屈服强度和拉伸强度。这种金属间相具有热稳定性和冶金稳定性，有望促进晶界强化。它还增加了晶界在高温下流动的阻力。由于具有锋利边缘的 Al11RE3 脆性相的生长，进一步增加 RE 添加量会降低强度和延展性。尽管如此，当稀土添加量为 3 wt% 时，合金的高温强度仍高于 AZ91。
The present article focuses on the high-temperature mechanical properties of the magnesium alloy AZ91. The addition of rare-earth (RE) elements up to 2 Wt pct improves both yield and tensile strengths at 140 degrees C by replacing the Mg17Al12 phase with RE-containing intermetallic compound. This intermetallic phase is thermally and metallurgically stable and is expected to boost the grain-boundary strengthening. It also increases the resistance of grain boundaries to flow at high temperatures. Further increases of RE additions reduce strength and ductility due to growth of the Al11RE3 brittle phase, which has sharp edges. Still, at a 3 wt pct RE addition, the strength of the alloy at high temperatures is more than that of AZ91.