Microabrasive wear behavior of borided steel abraded by SiO2 particles

Abstract

Boriding treatment was applied to AISI 1020 steel to improve its wear resistance. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy, Vickers microhardness testing, fracture toughness, and confocal microscopy. The microscale abrasive wear behavior was also investigated. SiO2 abrasive particles were used as abradant with slurry concentrations of 0.5 and 1.0 g/cm3. Normal loads of 0.49 and 0.98 N were used. Fe2B phase was identified in the boride layer via XRD analysis. The Fe2B layer was 169 μm thick with a mean hardness of 1608 ± 101 HV0.05 and fracture toughness of 5.35 ± 1.43 MPa m1/2. A reduction in the hardness of the outermost surface of the boride layer was observed owing to the formation of a porous region. Boriding treatment improved the wear resistance of the steel substrate. Sliding abrasive wear was the main mechanism under all tested conditions. The presence of micro-rolling abrasion and fracture-based mechanisms was observed for untreated and borided samples, respectively. Keywords: Microscale abrasion, Boriding, AISI 1020 steel, SiO2