Microstructure and wear behaviour of in-situ TiN-Al2O3 reinforced CoCrFeNiMn high-entropy alloys composite coatings fabricated by plasma cladding

• The in-situ TiN-Al 2 O 3 multiphase ceramic particles reinforced CoCrFeNiMn HEAs coating was prepared via plasma cladding. • The nano Al 2 O 3 were mainly wrapped by the micron TiN to form a multiphase ceramic structure. • The TiN-Al 2 O 3 particles are beneficial to enhance the hardness and wear resistance of the CoCrFeNiMn coatings. • The TiN-Al 2 O 3 particles promoted the abrasive wear and eliminated the adhesive wear during sliding process. The micro-nano TiN-Al 2 O 3 multiphase ceramics were in-situ synthesized in CoCrFeNiMn high-entropy alloys (HEAs) coating by plasma cladding. The as-prepared coating has a FCC single-phase. The hardness of TiN-Al 2 O 3 /CoCrFeNiMn HEAs composite coating was 17.6% higher than that of pure HEAs coating. The wear volume of the composite coating was 11.07 × 10 -3 mm 3 , which was 12.5% lower than that of pure HEAs coating. Furthermore, the TiN-Al 2 O 3 ceramic particles have significant effect to restrain the adhesive wear and promote the steady-state friction of the HEAs coating during sliding process.