APS TriplexPro-200 and HVOF K2: Comparison of Two Modern Thermal Spray Systems with Regard to Particle in-Flight and Coating Properties Using Iron Based Feedstock Materials

New and further developments in the field of thermal spraying systems (increased particle velocities, enhanced process stability) are leading to improved coating properties. At the same time innovations in the field of feedstock materials are supporting this trend. The combination of modern thermal spraying systems and new material concepts has led to a renaissance of Fe-based feedstocks. Using modern APS or HVOF systems, now it is possible to compete with classical materials for wear and corrosion applications like Ni basis (e.g. NiCrBSi) or metal matrix composites (e.g. WC/Co, Cr₃C₂/NiCr). This work focuses on that combination and wants to analyze the in-flight particle and spray jet properties achievable with two different modern thermal spraying systems (kerosene driven HVOF system K2, three-cathode APS system TriplexPro-200) and Fe-based powders. Velocity fields are measured with innovative diagnostic systems (e.g. laser doppler anemometry), temperature fields are determined with equipment like computer tomography. Additionally, resulting coatings are analyzed metallographically with regard to their properties and a correlation with the particle in-flight properties is given. The experimental work is accompanied by computational fluid dynamics (CFD) simulations of spray jet and particle velocities/temperatures, leading to a comprehensive analysis and characterization of the achievable particle properties with state of the art HVOF and APS systems.