Microstructures and Mechanical Properties of In Situ Synthesized TiC/TC4 Titanium Alloy Composite Coatings Prepared by Sol–Gel‐Assisted Laser Cladding

To enhance the surface wear resistance of TC4 titanium alloy, a TiC‐TiAl‐Ti 2 AlC ceramic composite coating is fabricated using a sol–gel‐assisted laser cladding technique. The effects of laser power on the microstructure and tribological properties are analyzed. The results show that the cladding layer develops typical granular and rod‐like TiC structures, while the transition zone exhibits lamellar, interwoven growth of TiAl and Ti 2 AlC. With the increasing laser power, TiC particles in the cladding layer tend to aggregate, while rod‐like structures decrease. The hardness of coating increases initially and then decreases with depth of the surface to the interior. The value of hardness reaches the maximum at ≈0.2 mm, attributes to the aggregation of TiC particles. During room‐temperature wear tests, the friction coefficient of coatings initially increases and then fluctuates around a stable value, with adhesive wear identified as the main wear mechanism. Elevated temperatures reduce the wear resistance of the coatings. At 500 °C, the friction coefficient shows significant fluctuations due to the formation of oxide films and delamination processes. Oxygen content on the wear surface increases significantly, with delamination and oxidative wear identify as the predominant mechanisms.