Surface morphology and Rietveld refinement characterisation of aluminium/titania nanocomposite produced by atmospheric plasma spraying and accumulative roll bonding

Abstract

ABSTRACT In this study, the nano-sized Titania (TiO2) particles were coated on an aluminum (Al) matrix using the atmosphere spraying method, and then the Al-TiO2 nanocomposite was fabricated by the accumulative roll bonding (ARB) process. The surface morphology evaluation by the field emission scanning electron microscopy (FESEM) revealed that TiO2 nanoparticles are uniformly spread and the amount of TiO2 nanoparticles decreased on the surface during the ARB process energy dispersive spectroscopy (EDS) mapping and X-ray diffraction (XRD) analysis demonstrated a decrease in the TiO2 phase while an increase in the Al phase in further cycles of the ARB process. Based on the atomic force microscopy (AFM) micrograph, the thicknesses of TiO2 particle clusters decreased from 1.26 μm to 238 nm by increasing the number of ARB cycles. The surface roughness values measured by the profilometer showed that the pressure of rolling has been an effect on reducing roughness to 96 micrometers, up to seven cycles of the ARB process. to calculate the Al crystallite size, TiO2 nanoparticles size, micro-strains and dislocation densities, the Rietveld refinement indicated that the increasing micro-strains and dislocation densities have led to reducing the Al crystallites and TiO2 particle clusters size to 234 and 40 nm, respectively.