Thermal spraying

[melrose]

I would like to ask the differences between oxyfuel spraying and plasma spraying and what are the advantages of thermal spraying over electroplating.

[Gordon]

Hi melrose

to the Surface Engineering Forum.

For basic introduction to the various thermal processes follow links:

Combustion Wire Thermal Spray Process
Metal Spraying
Combustion Powder Thermal Spray Process
Flame Spray Process
High Velocity Oxygen Fuel Thermal Spray Process
Detonation Thermal Spraying Process
Plasma Spray Process
Plasma Flame Theory

Though not oxyfuel or plasma the following links for other thermal spray processes:
Arc Spray Process
Cold Spray Process

Some advantages for thermal spray over electroplating:

• Much larger range of coatings
  
• Better suited to large components
  
• More portable process
  
• Little risk of hydrogen embrittlement
  
• Can be more environmentally friendly
  
• Thicker coatings generally
  

Some advantages of electroplating over thermal spray

1. Better for thin dense coatings
   
2. Better for coatings where oxides and porosity are not wanted
   
3. Better for small and complex shaped components
   
4. Bright smooth finish, finishing not usually required
   

That's off the top of my head, sure there are many more, but I think you need to consider specific coating types and the applications to make sensible comparison. Basically, one process is not better than the other until you evaluate what the coating is intended for. For example what would you choose for a gold coating on a watch strap or say a ceramic coating on a aircraft engine part. These examples are pretty clear cut, but say choosing between hard chromium electroplate and an alternative HVOF WC/CoCr coating is not so simple.

[melrose]

Thanks a lot Gordan! You are great!