Tribological Characteristics and Corrosion Resistance of Coatings Obtained by Electrospark Alloying, Pulsed Cathodic Arc Evaporation, and Hybrid Technology Using TiCNiCr and TiCNiCr-Dy2O3Electrodes

Single- and double-layer coatings on 40Cr steel substrates have been obtained by electrospark alloying (ESA) and a combination of ESA technology and pulsed cathodic arc evaporation (PCAE) using TiCNiCr and TiCNiCr-Dy(2)O(3)electrodes. The electrodes are obtained by powder metallurgy. The structure and elemental and phase composition of the electrodes and coatings are studied using scanning electron microscopy, energy dispersive spectroscopy, and X-ray phase analysis. The tribological properties of the coatings are determined as a result of tests according to the pin-on-disk scheme in contact with the Al(2)O(3)counterbody at loads of 1, 5, and 10 N. The temperature during the tests isT= 20 degrees C. The potential and current density of corrosion are determined using a three-electrode cell with a VoltaLab 50 potentiostat. The results show that the electrodes consist of TiC grains of 12 mu m; a solid solution of Ni in Cr; and, in the case of a doped electrode, Dy(2)O(3)up to 5 mu m in size. ESA coatings have a low-defect fine-grained structure consisting of regions of a solid solution of Ni and Cr in Fe and titanium carbide grains with a maximum size of 0.3 mu m. Coatings with the addition of Dy(2)O(3)have a lower coefficient of friction at loads of 1, 5, and 10 N. All coatings in 1 N H(2)SO(4)are in a stable passive state and have high corrosion resistance: the corrosion current density of the coatings is at least 4 times lower than the values obtained for a 40Cr steel substrate.