Study of microstructure and tribological properties of NiCrAlY coatings reinforced with Al2O3 particles

This study examines the influence of NiCrAlY powder with and without Al2O3 Reinforcement doses of 5, 10 and 20% by weight, produced by plasma spraying method have been investigated. In order to prepare a composite powder, shaft ball mill blender for an hour for each powder were used. The NiCrAlY powder and powder composite NiCrAlY / Al2O3 with values of 5%, 10%, 20% Al2O3 were coated on Inconel 718 substrates by plasma thermal spraying. In order to evaluate the microstructure, morphological and thermal stability evolutions of the powders and coatings were investigated using X-ray diffraction, scanning electron microscopy with energy dispersive spectroscopy and optical microscopy. Vickers micro and macro hardness test was used to evaluate the hardness..The pin-on -disk test with 5 N was used to cold resistance assessment of coatings. Findings showed that the composite coatings NiCrAlY/Al2O3 because of the size and morphology of different ingredients, has a higher porosity, but in terms of mechanical properties due to reinforced phase, improvements in composite coatings were observed. Evaluate the wear behavior of Al2O3 10% coatings showed that 37.7× 10-6(mm3/Nm)abrasion resistance better than other coatings, especially coatings from powders without reinforcement 114.6× 10-6 (mm3/Nm) abrasion resistance had.