Arc Spray:

Wire Spray:

Powder Spray:

PLASMA:
In this process ionized gas is used to heat and propel the tungsten-carbide at moderate speeds ( typically Mach I ) Operating costs are lower than HVOF and the bond strengths and overall densities are reduced. Higher cobalt content (17%) is used to create a tougher coating with some flexibility. Hardness is slightly reduced due to reactant's in the heat of the plasma.

HVOF:
In this process the powder is accelerated to trans-sonic speeds by the rapid combustion of fuel and large quantities of oxygen. The coating is extremely dense and the carbides are left unreacted by the heat and extremely hard. This is the hardest of the carbide coatings and will take moderate loads or impact. The system has high operating costs but HVOF is finding acceptance in roll facing and chrome plating replacement.

Spray & Fuse:
In this process the powder is deposited as a low velocity coating and then remelted at 2000 deg. F. The bonding is metallurgical and the compressive strength is very high with almost zero porosity. Used for resistance to abrasion where some impact or loading may occur. The drawbacks are the high temperatures involved to fuse the coating. Large components can now be fused using induction heating coils but this equipment is very expensive.