Oxidation Resistance of AlCrFeCuNi Alloy Modified by B-Doping in Vacuum Arc-Melting

The vacuum arc-melting high entropy AlCrFeCuNi alloy,an advanced wheel-hub material for electric railcar,was modified by B-doping to enhance its resistance against high temperature oxidation in friction-heating.The influence of the B-doping on the microstructures and oxidation-resistance was investigated with X-ray diffraction,energy dispersive spectroscopy,and scanning electron microscopy.The results show that the B-doping significantly increased the oxidation resistance instead of forming brittle borides.To be specific,the B-doped AlCrFeCuNi alloy showed the parabolic characteristics in constant temperature oxidation; oxidized at 800℃ for 5 h,0.1%(wt) B-doping decreased the size of dendrite grains,reduced outgassing of volatile Cr₂O₃,decreased surface porosity,eliminated formation of poriferous and lax structured metal-oxides,and promoted growth of compact surface metal-oxides layer.Consequently,the B-doped AlCrFeCuNi alloy displayed strong high temperature oxidation resistance in friction heating.