Abstract

This article investigated the effect of Mg content (4.5, 6.5 and 9.2, in wt%) on the damping capacities of Al–Mg alloys. The results indicate that the damping behavior can be divided into three regions. Region I refers to the low strain amplitude region (ε < 5 × 10⁻⁵), where the damping capacity decreases with increasing the Mg content and has almost no relation with the strain amplitude. Region II is the middle strain amplitude region (5 × 10⁻⁵ < ε < 8 × 10⁻⁴), where the damping capacity increases rapidly with the strain. Region III refers to the high strain amplitude region (8 × 10⁻⁴ < ε < 2 × 10⁻³), where the damping capacity remains constant and is independent of the strain when the strain is high enough, but increases with the Mg content. The damping values Q⁻¹ of Al–4.5Mg, Al–6.5Mg and Al–9.2Mg alloys are 0.01501 ± 0.00032, 0.01633 ± 0.00032 and 0.01862 ± 0.00119 at the strain of 1 × 10⁻³, respectively. The damping capacity in Region I is mainly determined by the lattice distortion caused by Mg addition and the restoring force caused by pinning points and Suzuki segregation. The extended dislocations break away from the pinning effect of Mg atoms and become moveable in Region II, and the movement of extended dislocations is the dominant damping mechanism in Region III.

Graphic Abstract

The damping behavior associated with the movement of extended dislocations and the force diagram of the extended dislocation segment.

中文翻译：

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镁含量对铝镁合金阻尼行为的影响

摘要

本文研究了镁含量（4.5、6.5和9.2，以重量％计）对铝镁合金阻尼能力的影响。结果表明，阻尼行为可分为三个区域。区域I是低应变振幅区域（ε  <5×10 ^-5），其衰减能力随着Mg含量的增加而降低，并且几乎与应变振幅无关。区域II是中间应变振幅区域（5×10 ^-5  <  ε  <8×10 ^-4），其中阻尼能力随应变而快速增加。区域III是指高应变振幅区域（8×10 ^-4  <  ε  <2×10 ^-3），当应变足够高时，阻尼能力保持不变，并且与应变无关，但随着Mg含量的增加而增加。Al–4.5Mg，Al–6.5Mg和Al–9.2Mg合金在1×10 ^-3应变下的阻尼值Q ^-1分别为0.01501±0.00032、0.01633±0.00032和0.01862±0.00119 。I区的阻尼能力主要取决于添加Mg引起的晶格畸变以及钉扎点和Suzuki偏析引起的恢复力。扩展的位错脱离了Mg原子的钉扎效应，在II区变得可移动，而扩展位错的运动是III区的主要阻尼机制。

图形摘要

与扩展位错的运动和扩展位错节段的力图相关的阻尼行为。