In mechanical engineering there is an increasing demand for lightweight design and materials engineering from the view points of weight reduction, reduction of consumed energy and upgrading of performance. One major drawback of light metal alloys is their poor tribological properties concerning friction and wear under high surface loadings. This study focuses on the development of combined coatings on light metal substrates which show high wear resistance and low friction coefficients under dry sliding conditions. The combined coatings consist of a thermally sprayed ceramic or metallurgical primary coating to provide the wear resistance. Subsequently a coating with dry lubricating ability is deposited to achieve a low friction coefficient, either by application of a lubricant lacquer containing microscale solid lubricant particles (e.g. PTFE, MoS 2 ), by cathode sputtering of MoS 2 or by deposition of pure carbon containing coatings (a-C:H) by plasma assisted CVD.

The increasing use of magnesium alloys in many engineering applications is mainly limited by their unsatisfying surface properties, especially the poor tribological properties and the poor corrosion resistance. Therefore an effective and well designed coating technology has to be adapted to allow a successful implementation of magnesium alloys under tribological load and in an corrosive environment. This presentation gives an overview of the performance of different functional metallurgical and ceramic coatings on magnesium diecastings which are applied by atmospheric plasma spraying (APS) and high velocity oxygen fuel spraying (HVOF).

This paper aims to fabricate wear resistant composite coatings on light metal substrates which also exhibit low friction coefficients. It demonstrates that combined ceramic polymer coating systems are a powerful concept for industrial applications where high wear resistance, creep resistance and compressive strength as well as low friction coefficients are required. The results show that, under the specific experimental conditions used, the titanium dioxide layer in connection with the applied lubricant lacquer showed better performance than the mixed aluminum oxide/titanium dioxide layers. Paper includes a German-language abstract.