Formation of Fe–Al intermetallic coating on low-carbon steel by a novel mechanical alloying technique

Abstract

A novel coating method, mechanical alloying, was used to layer a Fe–Al solid solution on the surface of low-carbon steel. During the mechanical alloying process, moving balls and powder particles impacted the substrate surface. The coating process was performed in a planetary ball-mill using a milling time that varied from 1 to 10h, a ball-to-powder ratio of 10:1, and a ball-mill velocity of 200rpm. Al2024 powder was used as a new raw material for metal deposition. The surface morphology of the coatings was characterized by scanning electron microscopy (SEM). Local compositional analysis and intermetallics formation were analyzed by electron microscopy with energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The results revealed that a Fe–Al coating was formed on the surface of the low-carbon steel substrate by the formation of Fe–Al intermetallics.