Microstructure evolution and mechanical properties evolution of high-Zn Al-Zn alloys prepared by cross accumulative roll bonding combined with heat treatment process

Abstract

The cross accumulative roll bonding (CARB) combined with the heat treatment process was used to develop high-Zn Al-xZn alloys with 20 and 50 wt% Zn. The effect of the Zn content and fabrication process on the microstructural evolution, microhardness, tensile, and wear behaviors was investigated by using scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectrometry (EDS), microhardness indentation, uniaxial tensile, and wear testing (pin-on-disk) at room temperature. The microstructure of the Al-20 wt% Zn alloy featured α-Al granular structures, whereas by Zn content increasing to 50 wt% the structure was α + η eutectoid structures with a fine distribution. The increase of the Zn element from 20 to 50 wt% was accompanied by a significant increase in tensile strength and also microhardness, but reduction in the elongation percentage of the Al–xZn alloys. Additionally, the wear resistance was improved as the Zn content was increased from 20 to 50 wt%. Finally, mechanical results confirmed that by increasing Zn content in the developed alloys the mechanical properties improved.