HAI Advanced Material Specialists

Solutions>Spray Processes

Spray Processes

Thermal Spray Powders

Thermal Spray Wires

Wire Spraying

Twin-Wire Arc Spray (Electric Wire Arc Spray)
Electric wire arc spray is achieved by energizing two wires of the coating material at different continuously fed together at an angle. A flow of compressed gas atomizes and accelerates the molten particles toward the substrate.

Single-Wire Combustion Flame Spray
Combustion flame spray is acheived by burning a mixture of oxygen and acetyline in a torch having a flame-accelerating nozzle. For material in wire form, the flame is concentric to the wire fed through the nozzel axis. Combustion gas melts, atomizes, and propels molten particles to the surface for coating. Powders are injected into the flame nozzle by carrier gas, where they melt and are projected to the surface.

Powder Spraying

HVOF Spray is achieved using a oxygen-fuel mixture (propylene, propane, and hydrogen or natural gas). The coating material is fed axially through the gun using nitrogen as a carrier gas. The fuel gas is mixed with oxygen in a proprietary siphon system in the front portion of the gun. The gases are then ejected from the nozzle and ignited externally of the gun. the ignited gases form a circular flame configuration which surrounds the unformly heats the powdered spray material as it exits the gun and is propelled to the surface.

Plasma spray is achieved by using heat transfer form a high-KW electric are to a plasma-forming gas directed through flow enhancing nozzles. Within the spray device the gas flow chamber contains an axial stick cathode adjacent to the nozzle witch forms a ring anode. In the controlled gap a CD arc is maintained through with the existing gas must pass. Heated to nominal temperatures of 10,000F part of the gas ionized to plasma. Ceramic or metallic powder is injected into the exit plume. It melts or is plasticized in the hot gas and propelled at high velocity to the part surface. Dilution of the plume and refined cooling techniques keep surface temperature low.