Effect of Ti addition on high-temperature properties of AlCoCrFeNi2.1 coating prepared on Ti-6Al-4V alloy

The AlCoCrFeNi2.1Tix (HEA-xTi) coating was successfully prepared on Ti-6Al-4 V (Ti64) ingots through spark plasma sintering (SPS). The addition of Ti dopants resulted in a marked refinement of the grains in the HEA coating, leading to an increase in hardness and improvement in adhesion. Additionally, the high-temperature oxidation resistance of the HEA coating was significantly enhanced. Further characterization of the oxidized HEA-0.2Ti coating revealed the presence of doped Ti served a similar role as reactive elements (RE) in the matrix. The segregation phenomenon, migration channel, supersaturation, and oxidation of Ti ions were all clearly observed and the underlying mechanisms were presented.