Thermal Spray – Here’s A Second Look

Sure, hard facing relates to thermal spray, though it’s really more about depositing’filler’materials onto a steel surface for repair or dimensional restoration. And, normally, these improvements relate solely to promoting wear resistance, alone.

But did you understand these’overlays’of material might also contribute to corrosion prevention, low friction, anti-fretting or galling, even release (nonstick) properties? What was formerly developed for rebuilding worn parts or those with machining errors is currently extending into many fields of surface engineering.

The principle of applying thermal spray is very basic. That’s, molten or semi-molten metals, alloys, or ceramics, atomized, are fed toward the task piece by a jet stream of air.

As these particles impinge the work surface, they dissipate their heat, quickly cooling, accumulating, fusing right into a cast-like structure described as highly cohesive. Resultant surface finishes, as-sprayed, typically range between 100 and 400 micro inch. So, based on requirements, finish grinding or polishing may be required. (Values under 10 micro inch are very much attainable.)

What forms of materials can be applied by thermal spray? bed liner The clear answer is most metals, ceramic, cermet(ceramic-metal combinations), tungsten carbide, even organic-based compounds like polyesters.

Adhesion, largely mechanical (versus metallurgical), is excellent. Grit blast, as a method of surface preparation, is typical to best promote adhesion. Though tensile strength can be sometimes superior with higher temperature processes, based on selection of material, through micro-welding or diffusion.

Common ways of application include HVOF (high-velocity oxygen flame), which is comparable to the combustion powder thermal spray process (LVOF), though with increased density, stronger bonds and lower residual tensile stress. Plasma spray and vacuum arc spray may also be popular.

Applications continue to develop with this specific technology. Food processing, packaging, molding, plastics, paper and chemical processing, are just a few of the newer, relevant applications. (Many materials are regarded non-objectionable with FDA.)

Ideally, try to find thermal spraying processes with minimal heat transfer to your projects piece. Just to ensure your surfaces are without any warping, surface distortion. Latest versions include’higher kinetic energy systems’to ensure highest density, particle-to-particle cohesive bonding. The result is long-lasting, cost-effective, surface performance.

The Teflon and Powder Coating Processes

The target of both Teflon coating and powder coating is basically similar, even though processes used to utilize each of them are slightly different. Both coatings are supposed to impart some specific property to that that’s being coated. For powder coating, the goal is really a protective layer that may keep that from being damaged, although with Teflon, usually a non-stick surface may be the property that’s intended to be given to that it has been applied to.

The Powder Coating Process

The powder coating that gets applied is simply that-a powder. It basically gets sprayed onto the top and then dries to create a coating. Here’s how the powder coating process works:

1. The powder is put in the feeder unit for the spray gun. Compressed air inside the machine then diffuses it such that it becomes like a fluid even though it continues to be technically a powder.

2. The gun siphons out the powder by pushing high velocity air and propelling the powder from the feeder to the gun.

3. Most guns can spray powder anywhere from 10 to 25 feet. When the powder leaves the gun, it appears like a cloud that’s moving toward that that’s being coded.

4. An electrode on the end of the spray gun emits a charge that’s offered to the particles of powder if they move across the tip. That charge causes the powder particles to start trying to find something to latch to and form a defensive coating over it.

So the powder coating process is extremely simple. After it’s been applied, it is baked onto the item. The entire process is simple to a typical painting job, except powder coating includes a great many benefits over ordinary paint. Like, any powder that doesn’t attach to that can be recycled, and the coating it provides is significantly thicker than paint. So powder coating is a way to provide a smooth, protective coating to something, so think about Teflon coating?

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