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

This work introduces some aspects of further improvement of the environment al friendly character of thermal spraying. After a short overview of the pr esent state of the technical development, general relations between the spr aying process and the environment will be discussed. Then, the possibilitie s 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 presente d 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 clas sified as being critical. The spraying behaviour of these powders and the w ear resistance of the coatings that are sprayed with them are not yet optim al. The results that have been obtained, however, allow us to draw the conc lusion that the way taken so far is the right way. Furthermore, possibiliti es 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 present ly not yet practicable in a techno-economically reasonable way, but it offe rs innovative possibilities for future developments. (C) 2000 Elsevier Scie nce B.V. All rights reserved.