A novel high-entropy alloy coating on Ti-6Al-4V substrate by laser cladding

Abstract TiZrAlNb and TiZrAlNbCo high-entropy alloys coatings are deposited by laser cladding on Ti-6Al-4V (TC4) alloy. The microstructure, hardness and corrosion resistance are studied. The results show that TiZrAlNb and TiZrAlNbCo high-entropy alloys coatings are BCC and BCC-FCC Matrix phases, respectively, accompanied by a small number of intermetallic compounds. The dendrite of TiZrAlNbCo alloy coating is much finer than that of TiZrAlNb alloy coating. Compared with TC4 substrate and TiZrAlNb alloy coating, TiZrAlNbCo alloy coating possesses high hardness of 768.944HV and excellent corrosion resistance (the Icorr is 3.66 × 10−9 A/cm2). The fundamental cause of microstructure optimization and performance improvement is the appearance of FCC phase in TiZrAlNbCo alloy coating.