Investigation of the influence of path planning and robot dynamics on near net-shape coatings

For a large number of industrial applications, thermally sprayed WC-Co coatings constitute an established concept for the wear protection of surfaces subjected to high tribomechanical stresses. Compared with thermal processes, particularly coatings which were applied by means of high-velocity oxy-fuel (HVOF) spraying exhibit not only improved mechanical properties but also the advantage of the slight divergence of the spraying plume. This offers process-induced advantages especially with regard to coatings with precise contours. However, it has not yet been possible to apply any post-processing free thermally sprayed coatings to forming tools. One new approach in this context is to use finely structured materials with an adjusted path strategy for the application of dense, smooth and thin coatings with uniform coating thicknesses. Before high-quality coatings can be applied to real forming tools, the effects and the fundamental mechanisms must be investigated on test geometries. In this study, an investigation is conducted into the influences of different path planning strategies and into the influence of the robot dynamics on the path application behaviour during the high-velocity oxy-fuel spraying process using fine WC-12Co powders on regular-geometrical inner radii with the objective of a nearshape low-post processing coating.