In 2019, we opened our surface coating R & D shop to explore the combination of robots, process control, and thermal spray. Thermal spray is a family of processes used for coating parts to improve thermal, corrosion, and wear resistance. There are several processes: plasma spray, high-velocity oxy-fuel, detonation gun, and twin wire arc spray. But in every case, these processes create mechanically bonded coatings. Coating bond strength is typically around 10,000 psi, which is adequate for many applications but 6 to 10 times lower than a metallurgical bond.
A unique exception is an old process called spray and fuse, which uses a self-fluxing brazing alloy as a matrix. After spraying, the part is fused, which creates a brazed or metallurgically bonded coating with much higher bond strength, less prone to bond line separations (failures) in high impact applications.
Spray and fuse is an old process. Combined with advanced robotic process control, it produces high quality, well-bonded coatings.
See the full video explaining the spray and fuse process and how to automate surface preparation, coating, fusing, and inspection: