The concentration o Benzotriazole plays an important role in the mechanical properties o ceramic coatings. In this work, hybrid nano-composite zirconia–alumina–Benzotriazole coatings with 1.2, 2.4, 3.6 and 4.8% o Benzotriazole are deposited on the Al 2024 substrate by the sol–gel technique. The phase, structure, and morphology are determined by grazing-incidence X-ray diraction, Fourier-transorm inrared spectroscopy, and eld-emission scanning electron microscopy and the nanomechanical properties are assessed by atomic orce microscopy at loads o 50 and 60 µN. Uniorm and homogenous amorphous coatings are deposited at 150 °C and the thicknesses o the zirconia–alumina and zirconia–alumina–Benzotriazole coatings with 1.2%, 2.4%, 3.6%, and 4.8% Benzotriazole are 670, 560, 750, 790, and 1040 nm, respectively. The surace roughness o the coatings decreases by 3.5 and 8 times ater introducing 1.2% and 3.6% Benzotriazole to the coatings, respectively, but urther increasing the Benzotriazole concentration rom 3.6 to 4.8% decreases the hardness, strength, and maximum shear tension. The optimal concentration o Benzotriazole depends on the Hertzian pressure and the hardness and strength o the zirconia–alumina–3.6% Benzotriazole under a load o 60 µN are 23 and 46 times higher than those o the zirconia–alumina coating. The smallest riction coecient o 0.11 is observed at a load o 60 µN and abrasive wear and shear are dominant.
