Thermal Spraying of FeNiW-Coatings to Improve the Performance of Casting Molds in the Aluminium Industry

The lifetime of casting molds in the aluminium industry is strongly limited by the high corrosiveness of aluminium melts and alternating thermal and mechanical loads.

By the use of sintered inlays of pseudoalloys with a high content of tungsten the lifetime of casting molds can be elongated to a factor of 1000. Replacing these massive parts by a coating would result in a considerable saving of costs.

PTA-welding of the materials proved to produce dense coatings but also effects in a high heat input in the base material.

Therefore thermal spray processes especially twin wire arc spraying and plasma spraying was investigated to produce appropriate coatings with a minimized heat input in the base material. By variation of the spray parameters the microstructure and density of the coating can be adapted to the application.