Pulsed process in which a measured charge of oxygen, acetylene and powder is ignited by a spark in a barrel roughly a meter long, several times per second, with a nitrogen purge between shots. Each detonation blasts the heated powder onto the part as a small round deposit a few micrometers thick, and overlapping shots build the coating. It produces dense, hard carbide and oxide coatings, and since every shot is a detonation, the gun runs inside a heavily soundproofed cell.
The seal rings stay in the D-gun cell, nobody wants to requalify them on HVOF.
Also heard as
- D-gun
- detonation spray
- detonation gun spraying
Related terms
HVOF
High-velocity oxygen fuel: burning fuel and oxygen under pressure to fire powder at supersonic speed.
Barrel
The long tube on an HVOF or detonation gun where particles are heated and accelerated before exiting.
WC-Co
Tungsten carbide in a cobalt binder, the most common wear-resistant thermal spray coating.
Booth
The soundproofed, ventilated enclosure where the gun, robot and part sit during spraying.