The formation of new (Al, Zn)3Zr precipitates in an Al-Zn-Mg-Cu aluminum alloy after aging treatment and their response to dynamic compression

This study mainly focuses on the newly developed (Al, Zn)(3)Zr precipitates through double aging treatment in an Al-Zn-MgCu 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 x-10(-3) to 3.0 x 10(3) s(-1) assisted by the strain hardening rate effect. The microstructures of Al alloy after the double aging treatment and dynamic compression at similar to 3.0 x 10(3) s(-1) contain novel (Al, Zn)(3)Zr 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.' precipitates is observed. The overlapped (Al, Zn)(3)Zr contains Cu solutes, while the.' 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)(3)Zr 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.

Automated summary

This study focuses on the newly developed (Al, Zn)(3)Zr precipitates through double aging treatment in an Al-Zn-MgCu alloy and their response to dynamic compression. The results show that the strength of the alloy is increased with an increasing strain rate, and the microstructures change after the dynamic compression.