| 摘要 |
A gas heating device is connected to a stagnation chamber having a Laval nozzle discharging a gas stream with incorporated particles at an ultrasonic speed, thus forming a cold gas spraying system capable of coating a surface by the accelerated particles. To achieve an better layer quality, at least one section of the cold gas spraying system, downstream of the gas heating device, is thermally protected by lining or forming the internal wall of the section with a ceramic insulation material having a heat conductivity of less than 20 W/Km to separate the internal wall of the section from the gas stream. A sleeve may be used, a portion of which is cylindrical and another portion which is a truncated conical section; the cylindrical section being inserted into the stagnation chamber and the conical section being inserted into the convergent subsection of the Laval nozzle. |
