Thermal Spray Decoded Part 2 of 3

THERMAL
SPRAY
DECODED


What you need to know about
the process and the companies
that do it for you.

4 Can any part or material be thermal sprayed?

5 What’s the difference between a non-thermal spray part and a thermal spray part?

6 Is one thermal spray source as good as the next?


Can any part or material be thermal sprayed?


In short, any material that can be melted can be sprayed by   thermal   spraying.   Depending   on   the   variation of thermal spray, material can be heated in a gun up to as hot as 14,000 C. However, the benefit of plasma & HVOF spraying is that these high temperatures stay inside the gun, transferring very little heat to the substrate itself. Substrate temperature rarely exceeds 300o C so coatings can be applied with little to no pre- or post-heat treatment while component distortion is minimal. With plasma   and HVOF spraying, coatings can be applied to thermal sensitive substrates like low melting point metals and plastics.


What is the difference between a thermal spray part and a non-thermal spray part?


Thermal spray coatings can be used as protection from heat, chemicals, molten metal, abrasion, adhesive wear galling, retting, and weathering. Thermal spray coatings can also be used to repair and renew worn components that would otherwise be too costly to replace. Non-thermal spray parts will generally be made with more expensive base materials in order to provide as many benefits in surface properties from the start of the process. While this non-thermal spray base material should be high quality, without a proper coating it will be subject to natural wear and corrosion, as well as any environmental factors that could expedite damage to the part. It also will be more expensive.


Is one thermal spray source as good as the next?


When deciding on a thermal spray provider, it is best to look for a company that also machines & finishes the parts that are being coated with thermal spray. It is important to remember that the coatings only make the base material better; a coating can make a sturdy part harder, but it can’t make a weak part strong.  As mentioned earlier, parts should be made with the coating process in mind, as there is an art to balancing the machining, turning, and grinding of a part with the coating.