The advantages and disadvantages of the cold spray coating process

Publisher Summary As with any other materials processing technique, the cold spray process has its own advantages and disadvantages. The main advantage of the cold spray process is that it is a solid-state process, which results in many unique coating characteristics. The main disadvantage arises due to the plastic deformation process, which leads to a loss of ductility of the coating. In the thermal spray processing technique, electrical, chemical or mechanical energy is used to produce a high velocity–high temperature gas jet. The coating material, usually in powder form, is introduced into this gas jet. In processes such as plasma and flame spraying, these particles are molten and the liquid droplets impinge on the substrate surface. Liquid flow and quenching leads to the formation of splats, which interlock with each other to form the coating. Processes such as the detonation gun and High Velocity Oxy-Fuel spray [“HVOF”] heat the particles close to their melting temperature, but do not fully melt them. These processes accelerate the particles to a greater extent than the plasma and flame spray processes. Upon impact onto the substrate surface, the enhanced kinetic energy is converted to thermal energy, resulting in particle fusion/melting and leading to the formation of splats.