Thermal spray v cold spray: the differences
Refinishing or repairing parts is a cost-effective way to extend their lifespan. However, selecting the right spray process can be challenging. Thermal spray techniques have been used for a century, while cold spray is a relatively recent development. But what are the differences between the processes?
What is thermal spray?
Thermal plasma spray coating uses a heat source to melt a powder coating. The molten droplets are then sprayed onto a substrate. Thermal plasma spray coatings such as https://www.poeton.co.uk/advanced-treatments/apticote-800-thermal-plasma-spray/ are used primarily on metal but can also be used to coat non-metallic substrates.
So why use thermal plasma spray for coatings? Thermal-sprayed components have a robust and corrosion-resistant finish and are easily customisable to suit your needs. Better yet, thermal plasma spray significantly extends your equipment’s lifespan.
What is cold spray?
Cold spray is used to deposit coatings at a lower temperature than their melting point. As a result, metals can be deposited in their solid state without being melted or dissolved. Cold spraying uses high or low pressure to move spray powder down the spray nozzle, converting heat energy into kinetic energy.
A cold spray system is useful for wear-resistant coatings, improving the surface of materials and repairing hardware. It’s also ideal for coating ductile materials as no chemical heating or melting is required.
Thermal spray v cold spray
There are several significant differences between thermal and cold spray. The size of the coating particles is very different. Cold spray uses much finer particles, while thermal spray can spray ceramics and materials in wire form.
Cold spray creates no material oxidation, while minimal oxidation occurs during thermal spraying. However, engineering spray parameters can mitigate the potential for coating cracks during the thermal spray process.
Thermal spray is the right choice for brittle, high-density materials, while cold spray is better for ductile materials such as bronze and zinc.
Ultimately, which process you choose comes down to your priorities. Cold spray is worth looking into if you require less part distortion, while thermal plasma spray is a more established technology and could prove more cost-effective for your project.
