Features of the Formation of Electric Spark Coatings on the Alloy CompoNiAl-M5-3 of Nickel Monoaluminide Using an Electrode of Eutectic Alloy Zr-18% Ni

Abstract

To improve the service properties of the CompoNiAl-M5-3 nickel monoaluminide alloy, protective coatings were applied by electrospark deposition using electrodes from the Zr-18%Ni eutectic alloy. Coatings were applied in an argon atmosphere using vibration and rotation type manual processing tools with both direct and reverse polarities connected. It was established that the maximum total weight gain on the cathode of 11.17×10-4 cm3 was achieved in the case of using a rotary tool with direct polarity connected. The resulting coatings are characterized by 100% continuity with a thickness of 20–25 µm, a hardness of 11.6–14.6 GPa, and an elastic modulus of 162–174 GPa. The use of the electric spark processing contributes to an increase in the hardness of the CompoNiAl-M5-3 alloy by 1.4–1.8 times, wear resistance from 3.3 to 16.2 times, heat resistance at a temperature of 1150 °C for 5 h, and a decrease in the friction coefficient.