Thermal spray coatings are used to protect surfaces and improve performance in different materials, from airplane parts to medical implants, to make products stronger, longer-lasting, and better suited to tough environments. Here’s a brief introduction to thermal spray coatings.
What Are Thermal Spray Coatings?
Thermal spray coatings are layers of material, usually metal, ceramic, or plastic, that are sprayed onto a surface. The material is heated until it becomes molten or semi-molten, and then sprayed at high speed onto the object. When it hits the surface, it cools and sticks, forming a strong, protective coating.
There are several different types of thermal spraying, including flame spraying, plasma spraying, and high-velocity oxy-fuel spraying. Each method uses a different heat source or speed, depending on the coating material and the job it needs to do.
Dense, Hard-Wearing, and Abrasion Resistance
One of the main strengths of thermal plasma spray coatings, like those shown at https://www.poeton.co.uk/surface-treatments/thermal-metal-sprays/plasma-coatings, is that they are dense and hard-wearing. A dense coating has very few gaps or holes, creating a strong protective barrier over the material to make the surface tough and long-lasting, even under heavy use. In addition to being dense, these coatings offer excellent abrasion resistance. They can stand up to rubbing, scraping, and other types of mechanical wear without breaking down.
Thermal Resistance
Another key feature of thermal spray coatings is their thermal resistance. Some coatings, particularly ceramic ones, can withstand extremely high temperatures without melting, cracking, or losing their strength, making them ideal for use in harsh, high-heat environments such as jet engines, gas turbines, and car exhaust systems.
Porosity and Abradable Applications
While many thermal spray coatings are made to be dense and tough, porosity – the presence of tiny holes or gaps – can also be a useful feature in some applications. A certain level of porosity can help trap lubricants, allow airflow, or reduce the weight of the part depending on the specific need. In addition, some coatings are designed to be abradable, meaning they are intended to wear down gently over time without damaging the parts they touch.
