The impact of ultrasonic shock surface treatment technology on the microstructure, mechanical and corrosion properties of FeCrMnCuNiSi high-entropy alloy coating via TIG arc melting

The effects of ultrasonic impact treatment on microstructure, mechanical and properties of high-entropy alloy (HEA) coatings prepared via TIG arc melting. The experimental results indicate that ultrasonic impact treatment eliminates the aggregation or segregation of metal elements within the high-entropy alloy coating. The acoustic stream's stirring effect results in a more uniform distribution of metal elements between dendrites and interdendritic regions. Additionally, ultrasonic impact treatment also strengthens the diffraction peak of the face-centered cubic (FCC) phase, which intensifies the distortion trend in the high-entropy alloy.The average grain size of the high-entropy alloy coating was reduced by approximately 55 % (from 253 μm to 112 μm), the average microhardness increased from 535 HV1 to 612 HV1 and the wear resistance improved by about 40 %. Additionally, the longitudinal tensile strength of the coating was also enhanced. The corrosion potential of the coating in a 3.5 wt% NaCl solution increased from −507 mV to −392 mV. The improvement in corrosion resistance of was about 23 %, the corrosion type mechanism changed from intergranular corrosion to uniform corrosion. These findings suggest that ultrasonic impact treatment technology has significant research value and promising application prospects, particularly in terms of improving the mechanical properties and corrosion resistance of metals during the forming process.