SAPS Service Thermal Spray Treatment Supersonic Plasma Spraying Metal Surface Coating Spray Process

The main difference is particle velocity. In supersonic plasma spraying the molten particles fly much faster (typically in the range of about 400 to 600 m/s or higher, compared with roughly 150 to 400 m/s in conventional APS), and the jet is more concentrated. As a result, the coatings are denser, with lower porosity, higher bond strength, and a more uniform microstructure.

The main advantages are dense, low-porosity coatings; high bond strength; high deposition efficiency; relatively high productivity; a smooth and compact coating surface; and good performance in wear, corrosion, and thermal-barrier applications. Because it still uses a plasma heat source, it can melt high-melting-point ceramics that combustion-based processes such as HVOF cannot handle well.

Key parameters include arc current and voltage (high-efficiency supersonic systems often run at high voltage and comparatively low current), plasma gas composition and flow rate, powder feed rate, spray or stand-off distance, traverse speed, and cooling conditions. These are optimized for each powder and coating requirement.