Strain-controlled low cycle fatigue properties of a rare-earth containing ME20 magnesium alloy
Strain-controlled low cycle fatigue properties of a rare-earth containing ME20 magnesium alloy
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含稀土 ME20 镁合金的应变控制低周疲劳性能
DOI：
10.1016/j.msea.2016.03.024
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发表时间：
2016-04-20
期刊：
影响因子：
6.4
通讯作者：
Ma, Z. Y.
中科院分区：
文献类型：
--
作者：
Mirza, F. A.;Wang, K.;Ma, Z. Y.
本研究的目的是评估的应变控制的循环变形特性和低周疲劳（LCF）寿命的低（类似0.3重量%）含Ce，ME 20-H112镁合金。该合金含有等轴晶与椭球形颗粒含有Mg和Ce（Mg 12 Ce），并表现出相对较弱的基面织构。与高稀土含量的镁合金不同，ME 20 M-H112合金由于在循环变形过程中存在孪晶-去孪晶活动，表现出与不含稀土的挤压镁合金类似的不对称磁滞回线。虽然循环稳定几乎没有实现，即使在较低的应变幅，循环软化是在大多数应变幅的主要特征。ME 20 M-H112合金的疲劳寿命与挤压态无稀土镁合金的疲劳寿命基本相当，可用Coffin-Manson定律和Basquin方程描述。观察到疲劳裂纹从近表面缺陷开始，与典型的疲劳条纹相比，本合金在裂纹扩展区域显示出一些浅的韧窝，沿着具有一些准解理特征。(C)2016爱思唯尔B. V.保留所有权利。
The present study was aimed to evaluate the strain-controlled cyclic deformation characteristics and low cycle fatigue (LCF) life of a low (similar to 0.3 wt%) Ce-containing, ME20-H112 magnesium alloy. The alloy contained equiaxed grains with ellipsoidal particles containing Mg and Ce (Mg12Ce), and exhibited a relatively weak basal texture. Unlike the high rare earth (RE)-containing magnesium alloy, the ME20M-H112 alloy exhibited asymmetrical hysteresis loops somewhat similar to the RE-free extruded Mg alloys due to the presence of twinning-detwinning activities during cyclic deformation. While cyclic stabilization was barely achieved even at the lower strain amplitudes, cyclic softening was the predominant characteristics at most strain amplitudes. The ME20M-H112 alloy showed basically an equivalent fatigue life to that of the RE-free extruded Mg alloys, which could be described by the Coffin-Manson law and Basquin's equation. Fatigue crack was observed to initiate from the near-surface imperfections, and in contrast to the typical fatigue striations, the present alloy showed some shallow dimples along with some fractions of quasi-cleavage features in the crack propagation area. (C) 2016 Elsevier B.V. All rights reserved.