This study mainly focuses on the newly developed (Al, Zn)₃Zr precipitates through double aging treatment in an Al–Zn–Mg–Cu alloy (Al alloy) and their response to dynamic compression. The results show that the strength of the Al alloy after aging treatment (393 K for 8 h + 433 K for 10 h) is increased with an increasing strain rate from 1.0 × 10⁻³ to 3.0 × 10³ s⁻¹ assisted by the strain hardening rate effect. The microstructures of Al alloy after the double aging treatment and dynamic compression at \(\sim\) 3.0 × 10³ s⁻¹ contain novel (Al, Zn)₃Zr precipitate with LI2 ordered and tetragonal structures. The small inter-particle spacing of precipitates after double aging, solute diffusion during the aging treatment, and dynamic compression lead to the overlapping of the different precipitates. For instance, the overlapping of (Al, Zn)₃Zr and θ′ precipitates is observed. The overlapped (Al, Zn)₃Zr contains Cu solutes, while the θ′ precipitate contains Zr solutes assisted by solute diffusion through dislocations and the increase in temperature during the compression. Besides, the number and size of the platelet precipitates are also increased after the dynamic compression compared to the double aging treatment Al alloy. In this research, the newly observed (Al, Zn)₃Zr precipitate after double aging treatment, and post-high strain rate compression is suitable for successfully tailoring the precipitation of Al–Zn–Mg–Cu alloy and achieving optimum properties in the near future.

Graphical abstract

中文翻译：

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时效处理后 Al-Zn-Mg-Cu 铝合金中新 (Al, Zn)3Zr 析出物的形成及其对动态压缩的响应

本研究主要关注通过双时效处理在 Al-Zn-Mg-Cu 合金（Al 合金）中新开发的 (Al, Zn) ₃ Zr 沉淀物及其对动态压缩的响应。^{结果表明，随着应变速率从 1.0 × 10 -3}增加到 3.0 × 10 ³  s ^-1，时效处理（393 K 8 小时 + 433 K 10 小时）后铝合金的强度增加应变硬化率效应。经二次时效处理和\(\sim\) 3.0 × 10 ³  s ⁻¹动态压缩后的铝合金显微组织中含有新的(Al, Zn) ₃Zr沉淀物具有LI2有序和四方结构。二次时效后析出相间距小，时效处理过程中溶质扩散，动态压缩导致不同析出相重叠。例如，观察到(Al，Zn) ₃ Zr和θ'沉淀物的重叠。重叠的 (Al, Zn) ₃ Zr 包含 Cu 溶质，而 θ' 沉淀物包含 Zr 溶质，这得益于溶质通过位错的扩散和压缩过程中温度的升高。此外，与双时效处理铝合金相比，动态压缩后片晶析出物的数量和尺寸也有所增加。在本研究中，新观察到的(Al, Zn) ₃双时效处理后的 Zr 析出物和后高应变率压缩适用于成功定制 Al-Zn-Mg-Cu 合金的析出物并在不久的将来实现最佳性能。

图形概要