STUDY ON NIOBIUM CARBIDE COATING FORMATION ON AISI L2 STEEL USING THERMO-REACTIVE DEPOSITION METHOD

In the present research, to form niobium carbide coating on the surface of aisi l2 steel thermo-reactivedeposition method (trd) in a molten bath was used. niobium carbide coating treatment was carried out at 1173 k,1273 k, and 1373 k for 2, 4, and 8 hours. the molten bath contained 20wt.% borax (na2b4o7), 5 wt.% boric acid(b2o3), and 75 wt.% ferro-niobium. the presence and properties of the coated layer were studied by means of opticalmicroscopy (om), scanning electron microscopy (sem), and x-ray diffraction (xrd) analysis. the thickness ofcoating ranged between 6.6 ?m to 33?m depending on treatment time, and temperature. the effects of treatment timeand temperature on the coating thickness were studied. kinetic study of the formation of nbc coating showed thatgrowth of the coating is under the control of diffusion. the activation energy of the process was estimated to be 122kj/mol. a practical formula to estimate the coating thickness was suggested.