Optimizing strength and ductility in 7150 Al alloys via rapid electropulsing cyclic heat treatment

Abstract

In this work electropulsing cyclic heat treatment (ECHT) process was used to control the microstructure and optimize the mechanical properties of 7150 Al alloys. The results show that the 7150 Al alloys can achieve high strength and excellent ductility properties after only 10 times ECHT for 1 h. Moreover, the measured ductility properties of the 7150 Al alloys are superior to that of the as-received samples. The main reason is that ECHT accelerates the homogeneous nucleation of coherent Guinier-Preston (GP) zones and fine ƞ' precipitates, and increases dislocation density. The quantitative analysis results indicate that the strengthening mechanisms are mainly dependent on precipitation Orowan strengthening and dislocation strengthening. In addition, the effect of ECHT on the rapid nucleation of precipitates is also discussed in this study. Compared with the traditional heat treatment, the ECHT is a high-efficiency method, which can potentially be applied to age-hardening Al alloys and open new avenues for obtaining high-performance materials.