Influence of Plasma Arc Current on the Friction and Wear Properties of CoCrFeNiMn High Entropy Alloy Coatings Prepared on CGI through Plasma Transfer Arc Cladding

Abstract

High-entropy alloys receive more attention for high strength, good ductility as well as good wear resistance. In this work, CoCrFeNiMn high-entropy alloy (HEA) coatings were deposited on compacted graphite iron through plasma transfer arc at different currents. The microstructure and wear properties of the CoCrFeNiMn HEA coatings were investigated. The coatings are composed of single phase with FCC structure. The CoCrFeNiMn HEA coating had the highest microhardness of 394 ± 21.6 HV0.2 and the lowest wear mass loss when the plasma current was 65 A. All of the HEA coatings had higher friction coefficients than that of the substrate. There were adhesive, abrasive and oxidation wear forms in the HEA coatings with the wear couple of N80 alloy. The HEA coating presented higher friction coefficient and better wear resistance than compacted graphite iron.

The Effect of Heat Treatment on the Microstructure and Mechanical Properties of Plasma-Cladded CoCrFeNiMn Coatings on Compacted Graphite Iron

“…The chemical compositions of the powders are summarized in Table 1. The powders had been used in the previous work [32]. The X-ray diffraction pattern of the powder is shown in Figure 2, which shows that the powder has a single FCC phase structure.…”

“…Table 2 shows the chemical composition of the CGI. The CGI substrate has been used in other work [32]. The CGI substrates were cleaned with acetone and dried in an oven.…”

“…Most of the studies done by previous scholars mainly focused on the effects of the cladding process parameters on the microstructure and properties of the coatings, but minor attention was paid to the effect of heat treatment (e.g., temperature and holding time) on the grain size and properties of the coatings after plasma cladding. In previous work, CoCrFeNiMn coating was prepared on a cast iron substrate using PTA technology to improve the properties of the substrate, and the effects of plasma cladding current on the microstructure and the friction and wear properties of the CoCrFeNiMn coatings were mainly investigated [32].…”

“…In order to improve the performance of the claddings, it is necessary to investigate the influence of heat treatment on its performance. On the basis of the previous research results [32], the coating prepared with a 65 A current was selected for this work. Thermal analysis of the coatings was carried out to develop the appropriate heat treatment process.…”

Effect of Heat Treatment on the Microstructure and Mechanical Properties of Plasma Cladded CoCrFeNiMn Coatings on Compacted Graphite Iron

“…Most of the studies done by previous scholars mainly focused on the effects of the cladding process parameters on the microstructure and properties of the coatings, but did not investigate the effects of the heat treatment process (e.g., temperature and holding time) on the grain size and properties of the coatings after plasma cladding. In a previous work, CoCrFeNiMn coating was prepared on a cast iron substrate using PTA technology to improve the properties of the substrate, and the effects of plasma cladding current on the microstructure and the friction and wear properties of the CoCrFeNiMn coatings were mainly investigated [31]. The preferred wear resistance was achieved when the plasma arc current was 65 A.…”