What is Thermal Spray Coating?

A coating produced by a process in which molten or semi-molten particles are applied by impact onto a substrate.The impacting molten particles on the substrate rapidly solidify to form a coating.

For better comprehension, the following sketches show the different steps of spraying:

• Fusion
• Atomisation and speed up
• Temprature and speed control
• Coating building

• Transport of the spraying particles
• Impact on the surface
• Thermal transfer from particles to substrate
• Solidification and contraction of particles
• Mechanical bond
• Local fusion

This process carried out correctly is called a "cold process" (relative to the substrate material being coated) as the substrate temperature can be kept low during processing avoiding damage, metallurgical changes and distortion to the substrate material.