Influence of magnesium on grain refinement and ductility in a dilute Al–Sc alloy
Influence of magnesium on grain refinement and ductility in a dilute Al–Sc alloy
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镁对稀 Al-Sc 合金晶粒细化和延展性的影响
DOI：
10.1016/s1359-6454(01)00262-2
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发表时间：
2001
期刊：
影响因子：
9.4
通讯作者：
T. Langdon
中科院分区：
文献类型：
--
作者：
M. Furukawa;A. Utsunomiya;K. Matsubara;Z. Horita;T. Langdon
通过等通道转角挤压（ECAP）方法研究了镁对Al-0.2%Sc合金晶粒细化和拉伸塑性的影响。实验结果表明，对于Mg含量为0 ~ 3%的合金，ECAP可使晶粒尺寸减小到≤ 0.70 ~ ≤ 0.20 μm，而对于Mg含量为5%的合金，由于在挤压过程中需要进行额外的退火处理，挤压后晶粒尺寸增大到≤ 0.3 μm。在Mg含量为0 ~ 3%的合金中，ECAP引入的超细晶在高温下是稳定的：在750 K以下退火1h后，所有合金的平均晶粒尺寸均小于5 μm。含3%Mg的合金具有较高的超塑塑性，而含0.5%和1%Mg的合金具有与常规Al-Mg合金相同的塑性。结果表明，添加0.3%的Mg是最佳的实现在Al-0.2%的Sc合金在快速应变速率的超塑性延伸。
Experiments were conducted to determine the influence of magnesium additions on grain refinement and tensile ductility in an Al–0.2% Sc alloy processed by equal-channel angular pressing (ECAP). The experiments show ECAP reduces the average grain size to within the range of ∼0.70 to ∼0.20 μm for alloys containing from 0 to 3% Mg but the as-pressed grain size increases to ∼0.3 μm in an alloy with 5% Mg because it is then necessary to use additional annealing treatments during the pressing process. The ultrafine grains introduced by ECAP are stable to high temperatures in the alloys containing from 0 to 3% Mg: in all alloys, the average grain size is <5 μm after annealing for 1 h at temperatures up to ∼750 K. High superplastic ductilities were achieved in the alloy containing 3% Mg but alloys containing 0.5% and 1% Mg exhibited the enhanced ductilities generally associated with conventional Al–Mg alloys. The results suggest the addition of ∼3% Mg is optimum for achieving superplastic elongations at rapid strain rates in the Al–0.2% Sc alloy.