Modeling Properties of HVOF Thermally Sprayed WC-Co Coatings Based on Particle-in-Flight Characteristics

Abstract

Abstract Numerous factors, such as the spray parameters and non-predictable conditions, during the spraying process influence the properties of thermally sprayed coatings. However, the condition of the particles at the moment of impact on the substrate is the most crucial factor for the morphology and the mechanical properties of a coating. Thus, nowadays particle analyzing systems are employed in order to explain the relation between the process parameters and the properties of a layer. Yet, modeling of thermal spray processes is conducted disregarding particle parameters and only correlating process parameters with layer properties. This article presents a new approach on process modeling, for relating spray parameters to particle-inflight conditions. The modeling of the particle properties in relation to the process parameters shall allow conducting targeted adjustments during the running process, to optimize particle properties. This method will enable to influence coating properties during the spraying process, eliminating the influence of unpredictable environmental or process-related disturbances. In a series of experiments, spray beam properties were measured in an HVOF thermal spray process with agglomerated and sintered WC-Co powder. Spray parameters were correlated to the particle-in-flight conditions, which were measured by utilizing two particle analyzing systems.