Tribological behavior of detonation sprayed CrFeNiAl0.3Ti0.3 high entropy alloy coatings in seawater environment

In this study, the CrFeNiAl0.3Ti0.3 high entropy alloy coating was deposited onto a SUS304 substrate steel by detonation spraying. The CrFeNiAl0.3Ti0.3 coating consists of FCC, BCC and B2 phases. It's hardness, bonding strength and porosity are 576 HV, 86 MPa and 0.87%, respectively. In seawater, the tribological properties of the coating depends on the counterparts. The CrFeNiAl0.3Ti0.3/SiC sliding -pairs presents the best tribological properties in seawater due to the lubricious SiO2 & sdot;nH2O and a dense tribo-layer. For AISI 440 C and Al2O3 counterparts, moderate abrasive wear occurs for the coating. For CuZn40 alloy counterpart, a soft copper -rich tribo-layer reduces the wear. For Ti6Al4V counterpart, many hard TiO2 and Al2O3 abrasion particles lead to the severe wear of the two contacting surfaces.