A SPS (Suspension Plasma Spray) process is shown from the start through the completion of a coating production. Included with the SPS footage is video of two process diagnostics which show the feedstock injection entering the plume and the droplet velocity and temperature at the standoff distance. This video features three Progressive Surface thermal spray products the:
• LiquifeederHE® suspension and solution feed system. This system provides closed-loop control on the flowrate of liquid-based feedstocks while simultaneously monitoring the pressure and density of the flow. The LiquifeederHE® design has been optimized for a production environment through being able to accommodate multiple supply tank volumes, minimize the flowrate stabilization time prior to spraying, and reduce maintenance with automated cleaning features.
• 100HE high energy/enthalpy plasma torch. This DC arc torch can be operated continuously at power ranges up to 105 kW on binary or ternary gas mixtures of Ar, H2, He, or N2. These characteristics make the 100HE® a very effective and versatile platform for handling the increased energy requirements inherent in liquid feedstock processes. For example, the 100HE® has been used to produce a columnar yttria-stabilized zirconia (YSZ) coating from a 40 wt% powder suspension at a flowrate of 130 ml/min (62 g YSZ/min) with a deposition efficiency of greater than 50%.
• CITS Pro® closed-loop gas and feeder control software. This software provides computerized control, monitoring, and data-logging of the entire thermal spray process and can be integrated with most major brands of thermal spray torches and feeders.
Progressive Surface has supplied feeders and complete SPS systems to a variety of worldwide customers. The primary interest in SPS has been to replace air plasma spray (APS) and electron beam physical vapor deposition (EB-PVD) YSZ coatings in aerospace applications and to produce dense yttrium oxide (yttria) coatings for semiconductor applications.