Plasma-sprayed wear-resistant coatings with respect to ecological aspects

This work introduces some aspects of further improvement of the environmental friendly character of thermal spraying. After a short overview of the present state of the technical development, general relations between the spraying process and the environment will be discussed. Then, the possibilities to contribute to an improvement of the environmental friendliness will be shown. The use of spraying powders on the basis of Fe-TiC will be presented first of all. These powders are produced by means of SHS synthesis. They do not contain any elements — or only on a limited scale — that can be classified as being critical. The spraying behaviour of these powders and the wear resistance of the coatings that are sprayed with them are not yet optimal. The results that have been obtained, however, allow us to draw the conclusion that the way taken so far is the right way. Furthermore, possibilities will be presented to reduce the amount of sealings or to use alternative, more environmentally friendly materials. Finally, a possible improvement of the properties of thermally sprayed coatings, which is based on a laser shock treatment, will be indicated. This type of laser treatment is presently not yet practicable in a techno-economically reasonable way, but it offers innovative possibilities for future developments.