Microstructure and Corrosion Resistance of TiN Coating on HSS by Pulsed Bias Cathodic Arc Ion Plating
TiN coating with thickness of 2.5μm was deposited on high-speed steel (HSS) substrate by pulsed bias cathodic arc ion plating. The surface and cross-section morphologies, composition depth profile and phase structure were characterized by FESEM, GDOES and XRD, respectively. Scratch test for adhesion evaluation, microhardness test for hardness measurement, and potentiodynamic polarization for corrosion resistance test were used. The results show that the TiN coating exhibits smooth surface, dense columnar grain structure and an obviously preferred orientation of TiN(111). The adhesion of the coating to substrate is exceeded more than 100N. The hardness of the coating is about 26 GPa. The low corrosion current density (Icorr) and rather high corrosion potential (Ecorr) value imply that the TiN coating displays a good corrosion resistance in 0.5mol/l NaCl solution. However, pitting is still existed due to the defects in the coating.
Yi Tan and Dongying Ju
X. H. Yao et al., "Microstructure and Corrosion Resistance of TiN Coating on HSS by Pulsed Bias Cathodic Arc Ion Plating", Materials Science Forum, Vols. 675-677, pp. 1307-1310, 2011