Characterization and friction–wear behaviors of laser thermal sprayed CoCrAlYTaSi coatings at elevated temperatures

Abstract

CoCrAlYTaSi coatings were fabricated on Ti–6Al–4V titanium alloy using a laser thermal spraying (LTS) at different power. The microstructure, chemical compositions and surface topographies of obtained coatings were characterized using a scanning electronic microscopy (SEM), energy dispersive spectroscopy (EDS), and atomic force microscope (AFM), respectively; the phases were analyzed using an x-ray diffraction (XRD), and the effects of power on friction–wear behaviors were investigated using a wear tester. The results show that the roughness of CoCrAlYTaSi coatings sprayed at the power of 800, 1100 and 1400 W was 8.09, 11.1, and 17.8 nm, respectively. The average coefficients of friction (COFs) of obtained coatings at the power of 800, 1100 and 1400 W are 0.77, 1.12, and 0.96, respectively, and the corresponding wear rates are 0.18 × 10–4, 0.22 × 10–4, and 0.59 × 10–4 mm3 N−1 · m−1, respectively, which increase with the increase of power, the wear resistance is significantly higher than the substrate, the wear mechanism is primary abrasion wear, accompanied by oxidation wear.