Useful Facts About Diffusion Coatings

By Marci Nielsen


the use and/or operation of metal components occurs in many different environments. The environments differ a lot and some of them cause significant effect on the metal. Effect may be caused by high temperatures or corrosive elements. Functionality, aesthetic value, and durability among other aspects get affected diversely by such adverse conditions. These effects led to research that led to the invention of diffusion coatings. These kinds of coatings are meant to offer protection to substrates against damage that results from environmental effects. This article will discuss the process and how protection is offered.

The process of applying a diffusion coating on a metal substrate is called diffusion coating too. This process is done inside a chamber at temperatures that are very high. Various metals such as nickel, iron, and cobalt are activated thermally during the procedure. Before the process can start, the substrate needs to be cleaned thoroughly first. Cleaning can be done through various methods, but abrasive blasting is commonly used. Cleaning is for removing dirt and other undesirable materials from the surface of substrates.

After proper cleaning has been done, the component is placed inside the container and the coating material added. The container is then completely sealed and placed into a furnace, which may be in the form of a chamber. The temperature of the furnace is then raised to very high levels in the range of 380 to 425 degrees Celsius.

When certain temperatures are attained within the aforementioned range, diffusion occurs to the metal. This makes it to make an alloy with the substrate. The nature of the substrate and the kind of metal used dictate how much time this process can last. However, most processes last from two hours to four hours. The substrate must be continuously turned throughout the process to achieve equal thickness.

The smoothness of the resultant coating is high while the thickness if uniform. Thicknesses can be varied to suit different functions. However, 15-80 micrometers is the normal range of thickness. The coating resembles the metal used in color. Iron, cobalt, chromium, aluminum, and silicon are some among the commonest metals in use. Various metals such as iron, steels, cobalt, and nickel can be coated.

The resultant coating provides significant resistance against oxidation, erosion, oxidation, and reaction with various substances such as water and air among others. This process has made metal components meant for critical functions more reliable, stronger, and more durable. Some of the metal components that are passed through this process include gate valves, power generation components, pump impellers, and gas turbines engine components such as cases, blades, and vanes.

The use of this process is mostly confined in industrial settings. Very few household devices incorporate this process in their production. The invention of the process happened several years ago and it has been undergoing modification over time to achieve perfection. Currently, better methods and technology exist.

Modern day furnaces are very efficient and have improved functionality because they incorporate several features. The coatings achieved today are thin yet very durable, strong, and efficient at avoiding corrosion. This technology is highly employed in the automotive industry.




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