Microstructure and high-temperature oxidation resistance of in-situ Al 2 O 3 reinforced AlCrFeTiV high-entropy alloy with boron microalloying

In this study, the effect of boron (B) on the microstructure and high-temperature oxidation resistance of AlCrFeTiV high-entropy alloy (HEA) coatings were investigated via laser cladding on Ti-6Al-4 V. The study findings indicate that AlCrFeTiVBx (x=0, 0.5, and 1 at%) HEAs coatings mostly comprise BCC solid solution phase, TiO 2 and Al 2 O 3 ceramic particles, which formed by oxygen (O) in the air reacts with Titanium (Ti) and Aluminum (Al) of coatings. Besides, the introduction of minor B should effectively reduce the formation of TiO 2 . Increasing the B content, significantly promoted the high-temperature oxidation resistance of HEAs coatings at 900 degrees C for 50 h. When x = 1, the coating exhibits the best high-temperature oxidation resistance. Furthermore, the oxidation mechanism of the coating was studied using first-principles calculations, and further investigation was utilized on the charge transfer of oxygen adsorbed on the BCC (1 0 0) surface.