In order to meet the requirement of self-lubricating and wear resistant properties of brush seal coatings for advanced aeroengines

two kinds of novel composite coatings

NiCoCrAlY-Cr2O3 and NiCoCrAlY-Cr2O3-AgMo

were prepared with plasma spray technology. Microstructures

phase compositions

mechanical properties

friction and wear performances of the above coatings were characterized and analyzed with scanning electron microscopy (SEM)

X-ray diffraction (XRD)

Raman spectroscopy and CSM high-temperature tribometer. The results show that both coatings exhibit very low porosity

high microhardness and tensile strength. The wear rates of two coatings are all at the order of 10-5 mm3· N-1·m-1

indicating the excellent wear resistance. The friction coefficient of the coating NiCoCrAlY-Cr2O3 decreases with temperature increasing

which shows a minimum value of 0.3 at 800℃ . NiCoCrAlY-Cr2O3-AgMo coating keeps a lower friction coefficient of about 0.23 from 400℃ to 800℃. Investigation of friction and wear mechanisms show that at 400℃

a lubricating film containing Ag is formed between the coating and the counterpart

while Ag2MoO4 formed above 600℃ effectively reduces the friction and wear at high temperatures.