Effect of Al element content on FeCr_1.5NiMnAl_x high entropy alloy cladding layer

Objective The aim is to study effect of Al element on microstructure and properties of FeCr_1.5NiMnAl_x (x = 1, 1.5, 2) high entropy alloy cladding layer. Methods FeCr_1.5NiMnAl_x high-entropy alloy cladding layers with different Al element content were prepared on Q235 steel by argon arc cladding. Microstructure, phase composition, surface hardness, wear resistance and corrosion resistance of cladding layers were analyzed. Results The results show that microstructure of FeCr_1.5NiMnAl_x high-entropy alloy cladding layer is dendritic structure. With the increase of Al element content, phase structure of cladding layer changes from mixed BCC phase + FCC phase to single BCC phase. Increase of Al element content promotes lattice distortion in cladding layer and is accompanied by precipitation of intermetallic compounds, thereby improving hardness and wear resistance of cladding layer. For corrosion resistance, corrosion form of cladding layer in 3.5wt.%NaCl solution is mainly pitting corrosion. With the increase of Al element content, self-corrosion current density of cladding layer gradually increases, and corrosion resistance gradually decreases. Conclusion Increase of Al element content leads to transformation of phase structure from mixed BCC phase + FCC phase to single BCC phase, and strip boride precipitates between dendrites. When molar ratio of Al element is 2, hardness is up to 51.76 HRC, and wear loss is almost 0, which has better wear resistance. When molar ratio of Al element is 1, it has a lower self-corrosion current density and a significant improvement in corrosion resistance.