Many examples of industrial products demonstrate the successful combination of sputtering and electroplating. Satellite components operating under extreme conditions in space are initially coated by a thin sputtered Cu film, a subsequent thick silver layer for effective reflection of solar radiation is deposited by electroplating. Hardness, biocompatibility and variable colour can be combined if a sputtered thin niobium film is oxidized by anodic oxidation.

The “teamwork” of surface treatment by dielectric barrier discharge and deposition sequences allows even more complex coating designs. In a so-called plasma printing process a local surface modification (generation of functional groups) is achieved by structured discharges. Subsequent local metallization is the basis for flexible circuit boards or various kinds of sensors.

A well established example for the use of hybrid processes in the optical coating industry is the anti-reflective film stack on plastic lenses for ophthalmics. First a several micron thick transparent scratch resistant film is applied, deposited by PECVD or a wet-chemical process, then followed by an electron beam evaporated interference coating of anorganic materials. High performance optical filters nowadays call for more sophisticated deposition processes. Magnetron sputtering of ultrathin pure metal films and oxidation in a separate oxygen plasma has shown to be a route to meet highest demands on precision even for several hundreds of individual layers. But also the combination of sputtering, ALD and PECVD may be a promising approach for the future of optical coatings.

Improvement of the mechanical and thermal properties of Ti-Al-N coatings can be obtained by multilayer architecture. Here, TiAlN/ZrN multilayer coatings, which have similar modulation period of ~6 nm and varied thickness ratios (λ) of ZrN versus TiAlN sublayers from 1:4 to 4:1, were synthetized using cathode arc evaporation. With the increase of λ value, a change from incoherent to coherent growth between TiAlN and ZrN sublayers is observed. Such a change leads to a modification of their mechanical properties. Especially, the TiAlN/ZrN coating with λ value of 4:1, which shows columnar structure with coherent growth, behaves the maximum hardness value of ~33.3 GPa. In order to better understand this structural change, the total energy and separation work of (200) crystal plane for TiAlN/ZrN are obtained by means of first-principles calculation. Increasing λ leads to a drop in the total energy as well as an elevated separation work, which is beneficial to the thermodynamic stability of coherent TiAlN/ZrN system. This calculation is in good agreement with the experimental results.

The financial support from National Natural Science Foundation of China (Grant nos. 51371201 and 51371199) is highly acknowledged. Li Chen thanks the support from the teacher research foundation (Grant No. 2013JSJJ005) and YuYing plan of Central South University of China.

In this contribution, nitride-based multilayer thin films relevant for machining industry (e.g. Cr-Al-N) are analysed regarding their mechanical and thermal properties. In particular, the influence of chemical composition and layer thicknesses on the film structure, hardness, and residual stresses as well as the thermal properties are investigated. The latter will be studied by combining experimental thermal conductivity measurements and continuum mechanics modeling.

It will be shown, how directional-dependent thermal transport properties of the coating can be tailored by optimizing the coating architecture, while at the same time sustaining high mechanical performance.

Regarding coatings for cutting tools, the coating supplier and tool manufacturer are confronted with different challenges. On the one hand, broadband coatings can increase efficiency of the tool manufacturing considerably, on the other hand sophisticated operations like machining of difficult to cut materials need highly specialized coating designs in order to enable efficient high performance cutting.