Abstract
Cored wires expand the spectrum of coating materials, that can be processed from wire feedstock. In particular they allow to provide a custom-made alloy composition. For many industrial applications a low thermal expansion coefficient is desirable to adapt the expansion behavior to specific needs. Bulk material alloys within the system Fe-Ni-Co show thermal expansion coefficients below 5 10–6 K–1 at temperatures below 600 °C. Thermal spraying is a suitable technology to manufacture coatings, that provide a gradient of the thermal expansion behavior, or free standing bodies for components with low shape changes due to thermal interference. Detailed research has to be done on the influence of the alloy composition regarding the specific metallurgical requirements on wire feedstock material for arc spraying. Fe-Ni(-Co) coatings are produced from cored wires by arc spraying. Guidelines for the choice of the optimum process parameters with respect to coating properties and economical effects are worked out. The coatings are characterized with concern to porosity, oxide content, surface roughness, deposition efficiency, power consumption and deposition rate. The coefficient of thermal expansion is determined by dilatometry.
