Electrospark deposition of high-entropic CrFeCoNiCu coatings on steel 35 in the granules mixture of pure metals

ABSTRACT

High-entropy coatings on steel 35 are obtained by the electro-sparking method in an equimolar mixture of CrFeCoNiCu granules from pure metals. The average thickness of the coatings reached 25 μm. According to the data of scanning electron microscopy, the structure of the coatings is represented by a matrix in which copper-rich inclusions are interspersed. Thermodynamic calculations showed that the matrix composition corresponds to a high-entropic alloy and the inclusion corresponds to a medium-entropic alloy. The heat resistance of the coatings increased with an increase in the duration of the pulses and for 100 hours of testing at 700 °C was 1.4–3 times higher than that of the back. The average hardness of the coatings was 6 ± 2.6 GPa, which is 3.6 times higher than that of steel 35. The average friction coefficient of the coatings in the dry slip mode was 0.44, which is almost two times lower than that of uncoated steel. The wear resistance of the obtained high-entropy coating was 2.4 times higher than that of steel 35.

KEYWORDS:

• Electro-sparking treatment
• granules of pure metals
• high-entropy coatings
• heat resistance of coatings
• coating friction coefficient