Manufacturing parameter analysis for alumina coating on steel substrate by automated image processing of isolated splats samples

Abstract

Thermal spray technology, which involves the Atmospheric Plasma Spraying (APS), encompasses a category of coating processes that supply surface properties to protect or improve the performance of a substrate or component. The coating produced by this technology is built by overlapped splats, whose morphology determines the coating properties. In the same way, the splats obtained in a separated distribution by interposing a perforated mask but using the same thermal spray parameters, has a relationship with the overlapped splats inside the coating. The samples with isolated splats have the advantage of being faster and cheaper to generate and analyse. This article analyses alumina plasma-sprayed splats on steel substrates by image processing techniques, which recognize individual splats and their corresponding morphology (doughnut and pancake) parameters. These parameters allow the user to efficiently classify the splats. After that classification, a quality control can be implemented by comparison between the original and checked sample of isolated splats and a new sample obtained during a small interruption in the normal operation. Additionally, these parameters obtained in an automated way can be used to evaluate the effect of different selections of spraying process parameters.

Mathematical Modeling and Analysis Using Nondimensionalization Technique of the Solidification of a Splat of Variable Section

“…The thermal spray system used was the SURFACE ONE from Oerlikon Metco, Switzerland, which includes a robot IRB 2600 of ABB, Switzerland. As González et al [45] explain, the parameters that control the spray process are electric current and Ar/H2 gas flow.…”