Effect of Al addition on structure and properties of sputtered TiC films

The article reports on the effect of Al addition on the structure, macrostress σ, mechanical properties and oxidation resistance of TiC-Al thin films. These films were sputtered using dc unbalanced magnetron equipped with a TiC target (purity 99.95%) fixed with an Al (99.99%) fixing ring of various inner diameters Ø_in. It was found that a continuous increase in Al content in the TiC-Al film results in (i) gradual change of the film structure from the crystalline TiC through X-ray amorphous TiC-Al to the crystalline Al₂Ti, (ii) decrease in the compressive macrostress (σ<0) up to its conversion to the tensile one (σ>0), (iii) decrease in film microhardness, H and (iv) increase in its oxidation resistance.