Characterization and Friction Wear Performance of Laser Thermal Sprayed Co30Cr8W1.6C3Ni1.4Si Coatings on TC4 Titanium Alloy
J-Y. Xu and D-J. Kong
Co30Cr8W1.6C3Ni1.4Si coatings were fabricated on TC4 titanium alloy using laser thermal spraying (LTS) using a fibre laser. The effects of laser power on the coefficient of friction (COF) and wear behaviours of Co30Cr8W1.6C3Ni1.4Si coatings were investigated using a high temperature wear tester at 500°C. The results show that metallurgical binding is formed between the Co30Cr8W1.6C3Ni1.4Si coating and the substrate, the surface roughness increases with the increase of laser power. The hardness of Co30Cr8W1.6C3Ni1.4Si coatings fabricated at the laser power of 1000, 1200 and 1400 W is 1271, 1049, and 979 HV, respectively. The average COFs of Co30Cr8W1.6C3Ni1.4Si coatings fabricated at the laser power of 1000, 1200 and 1400 W were 0.203, 0.291, and 0.369, respectively, the corresponding wear rates are 0.214 × 105, 0.464 × 105, and 0.984 × 105 μm3/Nm, respectively. The COFs and wear rates increase with the increase of laser power. The wear mechanism is primary abrasive wear and oxidation wear, fatigue and adhesive wear.
Keywords: Fibre laser, Co30Cr8W1.6C3Ni1.4Si coating, TC4 titanium alloy, laser thermal spraying (LTS), coefficient of friction (COF), wear mechanism