Thermal spray coating has been around since people first discovered how to turn metal into powder, which was well over 100 years ago. It was first patented in 1882!
The very early method used powdered lead for making batteries. Since then, many new materials and application techniques have been developed. It’s helpful to know just what kind of thermal spraying needs to be done for the job at hand. Here, we’ll take a look at what thermal coatings can do. Then we’ll break down few different kinds of spray coating processes and what they are best used for, so you can decide which one will be right for you.
What is Thermal Spray Coating?
This method of industrial coating uses a heat source to apply material typically powder or wire to a surface. The heat source melts the coating material into drops that can be sprayed onto the surface. Coatings can be applied to different thicknesses, depending on what they will be used for. The spray technique is faster than many other coating application techniques. Different types of coating materials and processes have different properties. Things like the hardness, porosity, and surface texture change depending on what coating you use and how it is applied. What coating process should you choose? Here are a few common ones and what they work best for.
This method uses a plasma torch to apply the coating material. This method is ideal for applying very thin layers – you’ll get a coat that can be measured in micrometers or millimeters. This is a flexible method that can easily be adapted for different materials. From the usual powder to ceramics and metals, this is a great, reliable method when you need to be able to apply thin coats of a variety of substances.
Combustion Flame Spray
If you need to spray a thermal coating on a delicate surface, the combustion spray method is a great choice. This method doesn’t use a very high flame velocity, so it won’t add as much stress to the surface you’re spraying. However, this low flame velocity also means that the coating will have less solidly adhered to the surface. Another benefit of this method is that it’s relatively inexpensive. If you have a surface that can’t handle a lot of stress or are looking to save money, this is the way to go.
High-velocity oxy-fuel, or HVOF spray, uses fast acceleration to send particles at a high speed, giving you a very thin, precise coating. This method creates coats that are well-adhered and strong, in spite of being thin, as long as the coating is applied evenly. This kind of coating is resistant to corrosion, but not very resistant to high heat. Use this method when you need a durable, strong coat that won’t be exposed to high temperatures.
With all of the modern developments in thermal spray coating technology, it is easier than ever to find the right technique for the task at hand. Consider the material you’ll be using, the surface it will be sprayed on, and the purpose it is being used for in order to make the right choice. The right coating method will hold up for as long as possible with minimal maintenance.