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• The Fe-Cr-Ni based composite coating was prepared using laser cladding method. • The addition of rare earth elements makes the cladding layer more dense and more refined. • Increased tensile strength, increased yield strength and increased impact value. Laser cladding technology was used to prepare Fe314 coating with added CeO 2 and La 2 O 3 on the surface of EA4T steel. The microstructure and structure of the coating were analyzed using scanning electron microscopy, electron probe microanalyzer, and X-ray diffraction. The mechanical properties of the coating were tested using a microhardness tester, universal testing machine, and pendulum impact testing machine. The results show that the addition of rare earth elements makes the cladding layer more dense and more refined; at the same time, compared to the base material, the tensile strength of the repaired specimen increased by 12.9 %, the yield strength increased by 23.3 %, and the impact value increased by 43.6 %. [ABSTRACT FROM AUTHOR]

[Display omitted] • The MoNbTaWTi-based refractory high entropy alloy coatings by laser cladding. • TiN/(Nb, Ti) 5 Si 3 particles were in-situ synthesized by adding nano-Si 3 N 4. • The high-entropy alloy coating structure primarily consisted of BCC, TiN, and (Nb, Ti) 5 Si 3 phase. • The Si 3 N 4 -2.0 coating exhibits the best wear resistance with an average hardness of 628.07 HV 0.1. MoNbTaW Refractory High Entropy Alloy (RHEA) coating has caught the extensive interest of researchers due to its simple body-centered cubic structure and excellent room temperature plasticity. However, it is difficult to prepare refractory high-entropy alloy coatings by laser melting due to its high melting point. In this study, MoNbTaWTi (Si 3 N 4) x: (weight ratio; x = 0.5, 1.0, 1.5 and 2.0) RHEA composite coatings were fabricated by laser cladding on the Ti-6Al-4V alloy. The experimental results show that laser cladding may produce TiN/(Nb, Ti) 5 Si 3 ceramic particles and BCC phases in- situ in the coating when nano-Si 3 N 4 is added. Moreover, the in-situ reaction between element Ti and element N in the molten pool can be release a large amount of heat, which can efficiently facilitate the synthesis of RHEA coating. The in-situ generated TiN/(Nb, Ti) 5 Si 3 ceramic particles significantly increase the hardness and wear resistance of the composite coatings. The influence of the content of Si 3 N 4 on the ceramic morphology, microstructure, microhardness, and tribology of RHEA coatings was comprehensively evaluated. [ABSTRACT FROM AUTHOR]