Effect of annealing temperature on the thermal stability of FeCrNiMnMo_xSi_0.5B_0.5 coatings

ABSTRACT

In order to acquire high entropy alloy (HEA) coatings with outstanding thermal stability, FeCrNiMnMo_xSi_0.5B_0.5(x = 0, 0.8, 1.0) HEA coatings were prepared on Q235 steel by the laser cladding technique. The phase structure, microstructure and microhardness of the HEAs were carefully investigated by a scanning electron microscope (SEM), X-ray diffraction (XRD) method and a microhardness tester, respectively. The experimental results show that FeCrNiMnMo_xSi_0.5B_0.5(x = 0, 0.8, 1.0) HEAs consist mainly of face-centred-cubic (FCC) solid solution plus a few FeMoSi phases, the microstructure evolves from wheat-shaped dendrite to net-like dendrite with the addition of Mo element. The microhardness of as-cladded coatings increases with the addition of Mo content, especially the FeCrNiMnMo₁Si_0.5B_0.5 coating. However, the microhardness change of annealed coatings is closely related to the number of intermetallic compounds and lattice distortion intensity of FCC solid solution.

KEYWORDS:

• High entropy alloy
• laser cladding
• microstructure
• phase
• microhardness

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This paper is supported by the National Natural Science Foundation of China [NSFC; grant number 51671061]; Natural Science Foundation of Guizhou Province (grant number [2016]1024); Natural Science Foundation of Guizhou Province.