Investigation of boron coatability of graphene reinforced medium entropy alloys

In this study, Fe/Co alloys were produced by adding nanoparticle structured graphene at different rates using two different production methods. The boron coatability of the obtained alloys and the effect of particle reinforcement on the coating layer thickness were investigated. Nano-sized (3nm) graphene was preferred as the reinforcement element in the study. The reinforcement rate is considered as a variable state. Samples were produced using both the casting method and the powder metallurgy method in the production of unreinforced, 2% and 4% graphene reinforced alloys. The produced alloys were coated with boron using the box boronizing method at 800 ˚C for 2 hours. Characterization of the samples produced in the study was carried out by scanning electron microscope (SEM), energy dispersive X-ray (EDS), X-ray diffractometer (XRD) and Vickers microhardness methods. While peaks belonging to CoFe, CoFe2O4 and Fe3O4 phases were detected in the XRD analysis results of the alloys produced by the casting method, peaks belonging to the CoFe, CoFe2O4, Fe3O4, FeO and C phases were determined in the alloys produced by powder metallurgy. While the hardness of the alloys produced by the casting method varies between 264 HV0,05 and 314 HV0,05, the hardness values of the alloys produced by the powder metallurgy method are between 258 HV0,05 and 270 HV0,05. Boride layer thickness varies between 22 µm and 30 µm in alloys produced by casting method, and between 23 µm and 34 µm in alloys produced by powder metallurgy. Peaks belonging to FeB, Fe2B, CoB and Co2B phases were observed in the XRD analyzes of the alloys produced by the casting method. In the XRD analysis results of the alloys produced by the powder metallurgy method, peaks belonging to the FeB, Fe2B and CoB phases were detected. It was observed that the surface hardness of the samples increased significantly after the boron coating process. It has been determined that the surface hardness of alloys produced by casting and boron coated is between 1918 HV0,05 and 2020 HV0,05, while the surface hardness of alloys produced by powder metallurgy and boronized varies between 2042 HV0,05 and 2124 HV0,05.