On achieving ultra-high strength and improved wear resistance in Al-Zn-Mg alloy via ECAP

In this work, the high strength AA7050 Al-Zn-Mg alloys were successfully processed by 1, 2, 3, 4, 5, and 6 passes Equal-channel Angular Pressing (ECAP) at room temperature. Alloys' growing strength is achieved after the increased ECAP passes. Besides, the combined effect of ultra-fine grains (UFG) with the average size of 46 nm, high dislocation density, and numerous nanoparticle precipitation contributed to the ultra-high strength in 6 passes aluminum ECAPed alloy. After the dry sliding wear testing, the microstructure refinement and improvement of strength lead to this transformation of the wear mechanism after ECAP passes. Furthermore, the linear relationship between strength and wear rate is observed in this investigated Al-Zn-Mg alloy, which is helpful to predict the corresponding wear rate and strength.

Automated summary

The high strength AA7050 Al-Zn-Mg alloys were successfully processed through multiple passes of Equal-channel Angular Pressing (ECAP), leading to ultra-high strength attributed to ultra-fine grains, high dislocation density, and nanoparticle precipitation. Furthermore, the wear mechanism shifted after processing, and a linear relationship between strength and wear rate was observed in the investigated alloy.