Laser cladded Co08–xTi3AlC2 coatings: Microstructure, corrosive–wear and electrochemical corrosion

Abstract

MAX phase played the positive role during the corrosive–wear process of metal coatings, and Ti3AlC2 was added into Co08 coating by laser cladding to improve its corrosive–wear and electrochemical properties. The effects of Ti3AlC2 mass fraction on the corrosive–wear and electrochemical properties of obtained coatings in 3.5 % NaCl solution were investigated using a reciprocating wear tester and electrochemical workstation, respectively. The results show that the Co08–xTi3AlC2 coatings are composed of Co (Ni, Cr, W, Mo), AlFe and Ti3AlC2 phases, and their hardness is increased with the Ti3AlC2 mass fraction. The average coefficients of friction of Co08–5 %Ti3AlC2, –10 %Ti3AlC2 and –15 %Ti3AlC2 coatings are 0.56, 0.47, and 0.41, respectively, and the corresponding wear rates are 418.99, 389.67, and 339.33 μm3 N−1 s−1, respectively, showing that the Co08–15 %Ti3AlC2 coating has the best friction reduction and wear resistance among the three kinds of coatings. The wear mechanism of Co08–5 %Ti3AlC2, –10 %Ti3AlC2 and –15 %Ti3AlC2 coatings are abrasive wear, adhesive wear, and abrasive wear/adhesive wear, respectively. Moreover, the corrosion resistance of Co08–xTi3AlC2 coatings is increased by the Ti3AlC2 mass fraction, which is attributed to the protection role of corrosion products by the addition of Ti3AlC2.