Mechanical and dry-sliding wear properties of boronized pure cobalt using boronizing powders with SiC as diluent

In this study, boronizing of 99.95% pure cobalt was performed in a solid medium by using Commercial LSB-II powders (that contain SiC) at 850, 900 and 950 °C for 2, 4, 6 and 8 h, respectively. The surface modified samples were examined by means of scanning electron microscopy (SEM)-energy dispersive spectroscopy (EDS), X-ray diffraction, microhardness tester and ring-on-block wear tester. Samples boronized had Co2B phase or Co2B plus Co2Si phases depending on the process temperatures. The depth of modified layer ranged from 40 to 186 μm, depending on treatment temperature and time. The hardness of boride layer is much higher than that of silicide layer and substrate, and the wear resistance of the boride layer is more excellent than that of the silicide layer.