Structure of ion-plasma sprayed coatings made of a high-entropy AlFeNiCoCuCr alloy

Abstract

The influence of the substrates' material from copper and stainless steel on the structure of ion-plasma coatings (IPCs) obtained by CIB-method- deposition of cathode arc-spraying products fabricated mechanically from the ingot of high-entropy alloy (HEA) AlCuCoFeNiCr with equiatomic composition is considered. The structures of the cathode material and the coatings are investigated by means of the optical and electron microscopies as well as x-ray diffractometry. As determined, the obtained coatings, in contrast to the structure of the cathode, do not contain dendrites, and their structure is represented by grains of different dispersity, which results from not only of different temperatures of substrate heating, but also of the cooling rate of condensed products. As shown, the coating deposited to stainless steel consists of both interdrop zones having a nanoscale structure (2.5-15 nm) with a b.c.c. crystal lattice and zones within the droplets where the grains have dimensions in the range of 15-50 nm and contain multiple phases of varying perfection degrees. In coatings on copper, the larger grains (150-350 nm) and a significantly smaller number of stable phases with a more perfect structure are revealed.