Morphology distribution and corrosion resistance of in-situ TiC/CoCrFeNi high-entropy alloy coating

CoCrFeNiTi x C x (x = 0.1,0.2,0.3) coatings were prepared on the surface of Q235 steel by laser cladding . The effects of in-situ synthesized TiC content on the microstructure and properties of the coating were studied by scanning electron microscopy, electron backscatter diffraction , transmission electron microscope and electrochemical corrosion . The results show that in-situ TiC mainly exists in the form of small particles in the matrix, and with the increase of Ti and C content, the distribution of in-situ TiC in the crystal becomes uniform and dispersed. The in-situ precipitated TiC in the coating has an obvious phase relationship with the matrix, TiC[ 1 ¯ 00]∥matrix phase [ 2 ¯ 1 ¯ 0], TiC(00 2 ¯ )∥matrix phase (1 2 ¯ 0). The electrochemical corrosion performance of CoCrFeNiTi 0.2 C 0.2 in 3.5 wt% NaCl solution is good, and the corrosion form mainly exists in the form of grain boundary corrosion and pitting corrosion . • In-situ TiC are successfully synthesized in CoCrFeNi high entropy alloy by adding Ti and C elements. • Morphology and distribution of in situ generated TiC and Cr7C3 are systematically elucidated. • The in-situ precipitated TiC in the coating has an obvious phase relationship with the matrix, TiC[ 1 ¯ 00]∥matrix phase [ 2 ¯ 1 ¯ 0], TiC(00 2 ¯ )∥matrix phase (1 2 ¯ 0). • The CoCrFeNiTi 0.2 C 0.2 corrosion current density of 1.994 × 10 −7 A/cm 2 , self-corrosion potential of −0.195 V, which is attributed to the ease of formation of TiO 2 passivation film.