<p>This paper examines the influence of tool traverse speed on microstructure and corrosion property of friction stir processed AA7075/graphene surface nanocomposites. The tool traverse speeds were selected as low, medium and high. X-ray diffraction analysis was used to determine the crystallite size and lattice strain, while the presence of nanoparticles was analyzed using Field Emission Scanning Electron Microscopy equipped with Energy Dispersive Spectroscopy (FESEM). The analysis of variance (ANOVA) results indicated that the tool traverse speed has a statistically significance effect on crystallite size. Tukey’s Honestly Significant Difference confirmed that medium tool traverse speed produced refined crystallite size, whereas high tool traverse speed led to larger variation in crystallite size. The surface nanocomposites processed at low and medium tool traverse speeds exhibited a defect free, ultrafine-grained microstructure, unlike those processed at high tool traverse speeds. The interrelationships between output parameters were analyzed using Pearson and Spearman’s correlation coefficients. A linear relationship was observed between crystallite size and lattice strain, while the relationships between crystallite size, corrosion rate, and lattice strain were monotonic. Crystallite size was inversely related to corrosion rate.</p>