Structural and corrosion behavior investigation of novel nano-quasicrystalline Al-Cr-Fe reinforced Al-matrix composites produced by ARB process

Abstract

In the present study, aluminum metal matrix composites (AMCs) reinforced with Al-Cr-Fe quasicrystal (AlQC) nanoparticles (3 and 5 wt%) and monolithic Al were produced by the accumulative roll bonding (ARB) process up to 8 cycles. X-ray diffraction (XRD) and scanning electron microscopy were employed for structural evaluation. XRD results confirmed the presence of AlQC nano-powders in the Al matrix and the decrease of the matrix crystallite size to a nanometric scale (105 nm) after eight cycles. Microstructural studies showed an improvement in the distribution of the AlQC nanoparticles in the matrix, as well as the connection improvement between Al layers by increasing ARB cycles. Density measurements also showed that theoretical density of the composite samples was greater than the measured density, which is attributed to the presence of voids and pores. Also, corrosion behavior investigations in 3.5 wt% NaCl solution showed that corrosion potential decreases and corrosion rate increases in the presence of AlQC nanoparticles as the reinforcement in comparison to monolithic Al. Finally, a decrease in the corrosion rate of the samples was realized by increasing ARB cycles to the 4 cycle and then an increase was detected by further increasing cycles up to 8 cycles.