EFFECT OF THE COMPOSITION OF ELECTRODES PRODUCED FROM ТiC–(Fe–Сr–Al–Si) ALLOYS ON THE FORMATION, PHASE COMPOSITION, AND PROPERTIES OF WEAR- AND HEAT-RESISTANT ELECTROSPARK-DEPOSITED COATINGS ON STEEL

Abstract

The structure, phase composition, and hardness of electrode materials produced by hot pressing of TiC–(Fe–9% Cr–1.5% Si–2% Al) alloys were examined. The binder amount in the alloys was changed in the range 20–90 wt.%. The phase composition, hardness, and oxidation resistance of the electrospark-deposited coatings made of the developed materials were studied at 900 °C with holding for 35 h, and their abrasive wear resistance was tested. The influence of sintering temperature in the hot pressing of electrode alloys and the spark discharge energy in the electrospark deposition process employing an ELITRON-22A device on the cathode (steel 45) weight increment was established. The developed electrode materials were used to make a coating 120–160 µm thick with the general thickness of the hardened layer and transition zone being 240–270 µm and 8.5–14.5 GPa microhardness (depending on the binder content of the alloys). The abrasive wear resistance and oxidation resistance of the electrospark-deposited coatings made of the developed alloys are two to three times higher than those of the coatings made of ТіС hard alloys with Co–Cr, Co–Ni, and Ni–Mo binders.