Suppressing the Lüders elongation in novel Al–Mg–Zn(-Cu) alloy via pulsed electric current
Suppressing the Lüders elongation in novel Al–Mg–Zn(-Cu) alloy via pulsed electric current
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DOI：
10.1016/j.msea.2023.145966
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发表时间：
2023-12
期刊：
影响因子：
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通讯作者：
Y. Geng;Zhen Zhang;Kangcai Yu;Di Zhang;Xinfang Zhang;Linzhong Zhuang
中科院分区：
文献类型：
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作者：
Y. Geng;Zhen Zhang;Kangcai Yu;Di Zhang;Xinfang Zhang;Linzhong Zhuang
脉冲电流作为一种绿色、高效的表面处理技术，近年来被广泛应用于汽车工业铝合金表面处理。在本研究中，我们报告的电流诱导抑制的Lüders效应的交叉Al-Mg-Zn（-Cu）合金，其特征在于（Zn + Cu）/Mg比低于1.0。我们的研究结果表明，Lüders伸长率最低的电流密度为1020 A/mm 2。透射电子显微镜和X射线衍射的微观结构表征表明，在变形过程中施加脉冲电流加速了位错的湮灭和迁移。在微观结构分析的基础上，建立了相应的数学模型，阐述了Lüders效应的抑制机理。通过将电流密度增加到接近20 A/mm 2，降低的位错密度与钉扎位错所需的较低溶质浓度相结合，导致弱的溶质-位错相互作用，从而抑制Lüders效应。
The pulsed electric current has been recently introduced as a green and efficient alternative to improve the surface quality of aluminum alloys for the automobile industry. In the present study, we report the electric current-induced suppression of the Lüders effect in the crossover Al–Mg–Zn(-Cu) alloys, which is characterized by a (Zn + Cu)/Mg ratio below 1.0. Our findings revealed that the Lüders elongation was lowest at a current density of ∼20 A/mm2. Microstructure characterizations using transmission electron microscopy and X-ray diffraction illustrated that the annihilation and migration of the dislocations were accelerated by applying pulsed electric current during the deformation. A relevant mathematical model was established based on the microstructural analysis to elaborate the suppression mechanism of the Lüders effect. By increasing the electric current density to near 20 A/mm2, the reduced dislocation density combined with the lower solute concentration required for pinning the dislocations resulted in a weak solute-dislocation interaction, thereby inhibiting the Lüders effect.