Characterization and properties of CuZrAlTiNi high entropy alloy coating obtained by mechanical alloying and vacuum hot pressing sintering

- CuZrAlTiNi coating was synthesized by mechanical alloying/hot pressing sintering.
- HEA coating is composed of solid solutions and AlNi2Zr intermetallics.
- HEA coating presents better HV and corrosion resistance than T10 substrate.
- Nano-precipitates, phase boundary and solid solution strengthening induce high HV.
- Wear resistance of coating is slightly improved in comparison with substrate.

CuZrAlTiNi High entropy alloy (HEA) coating was synthesized on T10 substrate using mechanical alloying (MA) and vacuum hot pressing sintering (VHPS) technique. The MA results show that the final product of as-milled powders is amorphous phase. The obtained coating sintered at 950 °C is compact and about 0.9 mm in thickness. It is composed of a couple of face-centered cubic (FCC), one body-centered cubic (BCC) solid solutions and AlNi2Zr phase. The interface strength between coating and substrate is 355.5 MPa measured by three point bending test. Compared with T10 substrate, the corrosion resistance of CuZrAlTiNi HEA coating is enhanced greatly in the seawater solution, which is indicated by the higher corrosion potential, wider passivation region, and secondary passivation. The average microhardness of the coating reaches 943 HV0.2, and is about 3.5 times higher than the substrate, which is mainly ascribed to the uniformly dispersed nano-size precipitates, phase boundary strengthening and solid solution strengthening. Moreover, the wear resistance of the coating is slightly improved in comparison with the substrate.

Microstructures of the cross-sectional areas and microhardness distribution along the depth of CuZrAlTiNi HEA coating.129