Thermal spray coatings are a response to the need to protect engine components and other parts from environments that can result in corrosion or other types of damage. Without some form of protection, these parts will have to be replaced or repaired on a frequent basis and may even suffer a catastrophic failure during operation. Additionally, thermal spray coatings can be used to add desired properties to components, such as changing their conductivity. In addition to these advantages, coatings can easily be applied, reducing production and maintenance costs.
The Thermal Spray Coating Process
A thermal spray involves depositing a coating on an object by use of a spray. There are a wide variety of specific thermal sprays, ranging from flame-based sprays to plasma jets. In general, the type of spray is dependent on the nature of the object being coated, the purpose of the coating and the nature of the material that will make up the coating.
Thermal spray coating systems are computer controlled and capable of extremely delicate spray applications. These systems can control the thickness of the coating, ensuring that the coating provides the desired properties. This is especially useful when applying a coating to electronic or precision-engineered components where the process must conform to exacting standards.
Thermal Spray Coating Feedstock Materials
There are a wide variety of feedstock materials that are used in thermal coatings. These materials can range from ceramic materials such as chrome oxide to metallic tungsten carbide coatings. The feedstock used is dependant on the ultimate purpose of the coating. For example, tough ceramic coatings are used to protect engine parts that are exposed to high temperatures and pressures, while other coatings may be designed to ensure that a medical implant will not react with the patient’s body. Finally, conductive coatings are used for electronic applications such as creating circuit boards.
Uses for Thermal Spray Coating Processes
Thermal spray coating is used in a wide variety of applications. Some of the most common include the following:
- Adding heat and wear resistant coatings to engine parts. Adding non-reactive coatings to components that may be exposed to corrosive substances. For medical purposes, thermal spray coatings can be used to ensure that an implant or prosthetic will not provoke an immune response from the patient’s body. A thermal spray coating can ensure that the component has the desired electrical properties. Coatings can be used for electromagnetic interference (EMI) and radio frequency interference (RFI) shielding, especially when weight and volume savings are important. Finally, when seeking to repair a part, coatings can be used to rebuild worn surfaces to their original dimensions. This can allow the reuse of components that would otherwise have to be replaced.
In some cases, thermal spray coating has found itself replacing earlier methods of protecting a part. For example, thermal spray coating techniques are increasingly displacing traditional hard chrome plating, due a number of economic and environmental advantages. In addition, because thermal spray coating can eliminate the need to replace parts, this technique is becoming preferred over older repair techniques by budget conscious businesses.
Thermal spray coating not only can help reduce long-term maintenance costs, but it also permits the production of components with properties simply not obtainable by other fabrication techniques. These advantages allow businesses making use of thermal spray coating to drastically reduce their costs, without compromising on the quality of their maintenance and fabrication. Because of these factors, the popularity of thermal spray coating techniques will certainly continue to increase for the foreseeable future.