Duplex Surface Treatment of AISI 1045 Steel Via Pack Boriding and Plasma Nitriding: Characterization and Tribological Studies

For the first time, formation of cubic boron nitride (c-BN), besides Fe2B and iron nitrides, was detected in boronitride coating, which was applied via a duplex diffusional surface treatment. Boronitride coating was applied on AISI 1045 steel substrates via duplex treatment of pack boriding and plasma nitriding (B-PN). Scanning electron microscope (SEM), X-ray diffractometer (XRD), and pin-on-disk wear test were utilized to evaluate microstructures, phases, and wear properties of the coatings. The surface of the as-coated sample exhibited a pebblelike and compact structure, and the cross-sectional morphology of the coatings showed a saw-tooth interface with substrate. Duplex treated sample revealed superior wear resistance in comparison with the borided one.