LAUSR

A dense Al2O3 interlayer was inserted into TiN to enhance the tribological and anti-corrosion properties of TiN hard coating via a hybrid process of magnetron sputtering and atomic layer deposition (ALD). The influence of the ALD-Al2O3 layer on the microstructure, mechanical, tribological and anti-corrosion properties of TiN was examined. The TiN-Al2O3 coating exhibits low friction coefficient and specific wear rate, due to the structure change and columnar refinement caused by the addition of amorphous ALD-Al2O3 interlay which improves the mechanical properties of hard coating. The improved corrosion properties of TiN are attributed to the fact that the insulating ALD-Al2O3 used as a sealing layer can prevent the corrosive chlorine ions migrating into the lower TiN layer and block the charge transport in coatings. Moreover, raising the insertion position of ALD-Al2O3 layer away from the steel substrate results in a further increase in the anti-corrosion property of TiN-Al2O3 composite coating.