Study of the adhesion of nc-TiC/a-C:H coatings on plasma-treated steel substrates
| Authors | |
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| Year of publication | 2014 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | Nanocrystalline titanium carbide embedded in an hydrogenated amorphous carbon matrix (nc-TiC/a-C:H) shows high hardness and Young's modulus together with low wear and low friction coefficient. The adhesion of nc-TiC/a-C(:H) films to industrially attractive substrates is often poor, therefore an adhesion promoting interlayer is routinely introduced to overcome this problem. The aim of the recent work is to study the adhesion of nc-TiC/a-C:H coatings to high speed steel substrates. The coatings were deposited by the hybrid PVD-PECVD process using the unbalanced configuration of the magnetic field. The substrates were treated by several methods including chemical, mechanical and plasma techniques. The influence of the cleaning time and bias voltage on the substrate holder on the resulting adhesion was studied. In addition titanium interlayers with various thicknesses were deposited on the substrates prior to the coating deposition in order to study its adhesion as a function of the interlayer thickness. The dynamic impact, Rockwell, scratch and indentation tests were used to study the effect of the above listed surface processing techniques on the resistance of the coating/interlayer/substrate system against mechanical damage. The indentation induced defects were studied using Fisherscope H100 and Hysitron TI950 nanoindentation equipments. The resistance of the interface against fracture was studied by comparison of the number of cracks around and/or below the residual indentation imprints. Details of microstructure in the vicinity of the indentation print were studied using transmission electron microscopes JEOL 2100F and Philips CM12 STEM and scanning electron microscope MIRA 3 FEG-SEM. |
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