Tuesday, December 1, 2015

Facts One Should Know About Diffusion Coatings

By Marci Nielsen


The operation and application of metal components is done in diverse environments. The variance in the environments is of great importance because some of the environments have diverse impacts on components. Corrosive environments and high temperatures for instance can be very damaging. Adverse environments impact functionality, longevity, and beauty of components. As such, in an attempt to reduce or eliminate the effects, diffusion coatings were invented. The purpose of these coatings is protecting substrates from being ruined by adverse environments. The information below discusses the process and how it offers protection to substrates.

Diffusion coating is the process through which metal substrates are coated with diffusion coating. The process requires a special piece of equipment called a chamber and optimal temperatures are usually very high. Thorough cleaning of substrate must be done first before the process is started. Abrasive blasting is the most commonly used method although other methods can be used. Unwanted materials must be removed because they prevent complete bonding between the metal and substrate.

Once the substrate has been cleaned properly, it is placed into a contained together with the metal used for coating. The container is then placed inside a furnace or a chamber. The furnace is turned on and the temperature set to the range of 380-425 degrees centigrade.

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.

This process is highly employed in industrial settings than it is applied in residential settings. In fact, very few equipment in homes need or have components coated this way. The process has been in use for long now, and since its invention, it has been modified severally. Modification are aimed at making it perfect in terms of the methods and technologies used.

Modern furnaces incorporate several important features that make them more effective and functional. The improved functionality and efficiency allows for the attainment of thin coats that last longer and are stronger, while offering good protection at the same time. The employment of this technology seems to be higher in automobile industry.




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