Abstract: Tribological properties, phase compositions and wear mechanisms of laser cladding NiAl coating were investigated from room temperature to 1000 degrees C under air atmosphere environment. The results showed that a glaze layer composed of NiO, Ni₂O₃, Al₂O₃ and NiAl₂O₄ phases as well as Ni3Al phase were formed on worn surface under high temperature, which act as a solid lubricant and anti-wear material improving the tribological properties of NiAl coating at elevated temperatures. The wear mechanism is dominated by abrasive wear below 500 degrees C, and transforms to plastic deformation and adhesive wear at 500 degrees C up to 700 degrees C and oxidation wear at 900 degrees C and above, owing to formation of new oxide phase during tribochemical reaction.

KeyWords Plus: OXIDATION BEHAVIOR; COMPOSITE COATINGS; MICROSTRUCTURE; WEAR; NANOPARTICLES; TRANSITION; FRACTURE

Published in TRIBOLOGY INTERNATIONAL, 104 321-327; 10.1016/j.triboint.2016.09.014 DEC 2016