Multicomponent Ti-Si-B-C superhard and tough composite coatings by magnetron sputtering

Multicomponent TiSiBC thin film with high harnness and modulus of 45 GPa and 520 GPa with 50% elasticovery after unloading have been sysnthesised by single target magne-tron sputtering. The thickness of the film was of the order of 4 mu m. The film showed less than 0.1 value for coefficient of friction. The film showed amorphous matrix with crystalline nano phases of TiB2, phase containing Ti and Si and TiC, which led to achieve higher hardness, mid-ulus with higher toughness. High values of hardness of these coatings were due the high density of boundaries between the small, nanometer size grains embedded in the matrix of amorphous TiSiBC phases. The tougness value Klc measured by nanoindentation was found in the range of 4.5-5 MP am(1/2).(c) 2012 Elsevier B.V. All rights reserved.