Feasibility study of producing Al–5Zn–1 Mg alloy by accumulative roll bonding process and subsequent heat treatment

Abstract

In this research work, Al/5Zn/1Mg (wt.%) composite sheets were produced by the accumulative roll bonding (ARB) process and then converted into Al-5Zn-1 Mg (wt.%) alloy sheets by a suitable heat treatment process. Scanning electron microscopy (SEM) combined with energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) were used for structural investigations. Mechanical properties of the specimens were also examined by using tensile and microhardness measurements. SEM microstructural analyses revealed the uniform distribution of Zn layers and Mg powder particles in the Al matrix by increasing the number of ARB cycles, as well as the formation of the α phase after the seventh ARB cycle and subsequent heat treatment at 390 °C in the alloy samples. XRD results confirmed the microstructural evolution and showed only peaks related to Al for the alloy samples after the seventh cycle. Tensile results showed that by increasing the number of ARB cycles from first to seventh, tensile strength and elongation increased from 117 MPa to 370 MPa and 8 to 13 %, respectively. Microhardness measurements also depicted the progressive increase in hardness by increasing the ARB cycles up to the seventh cycle. The results confirmed that the ARB process with subsequent heat treatment is a suitable method for Al-based alloy sheets fabrication with high mechanical properties responses.