In Reply to: Re: 4140 steel shafts & casings posted by Gerard on 06/16/02 at 7:10 PM:
There are a number of them Gerard. The Hot process creates a welded joint or a fused coating using common brazing techniques and like part temps.
The cold spray processes produce coatings for restoration of lost dimension to worn or mis-machined parts, corrosion protection, wear resistance, or some combination of those properties. These processes are often used to enhance the performance of metals through surface engineering.
The cold process coatings are applied by melting wires or powders with gas fuel equipment, or electric arc, or plasma. Part temps vary with the different processes and range from around 200°F up to a localized temp similar to welding (PTA system).
The most common equipment types can be viewed in the "Surface Engineering" section of our web site at http://www.usalloysweldtech.com