FIELD OF THE INVENTION

The present invention relates to the concepts of cold spraying. More specifically, but not exclusively, the present invention relates to a device and system for cold spraying by upstream mixing and hand-held or robotic manipulated nozzle operation.

BACKGROUND

The existing systems for cold spraying metal particles operate by mixing a pressurized gas together with a stream of powdered metallic particles. The resulting gas/metallic particle mixtures are sprayed onto an object, thereby applying the metallic particles to the surface of the object.

In a cold spray process, specially engineered sub-micron and micron sized solid state particles are accelerated to supersonic speeds through a convergent-divergent nozzle using such gases as helium and nitrogen or other like gases or even compressed air. When the particles impact the surface, they form a strong mechanical and metallurgical bond.

Currently, all existing cold spray systems mix the metallic powder and gas streams very near, at, or directly after the throat of a spray nozzle (i.e., within the spray nozzle body). For this reason, a heater is often included in the nozzle/spray gun assembly. This poses multiple problems, such as, the cold spray nozzle assembly must be large, and must be made even larger when gas pressures increase above 250 psi because the size of the heater must also grow to heat a greater quantity of gas; and the maneuver ability of the cold spray nozzle is limited because the powder supply feed line (which may be densely packed with flowing powder) cannot be easily manipulated because twists and kinks can cause blockages in the line. In such systems, the powder may be discharged from the nozzle at a temperature significantly lower than the temperature of the accelerant (i.e., the gas).

Therefore, a primary object, feature, or advantage of the present invention is to provide a cold spray device and system that includes a compact and highly maneuverable spray nozzle.

Another object, feature, or advantage of the present invention is to precisely control the temperature of the powder at discharge from the nozzle.

As still further object, feature, or advantage of the present invention is to provide a cold spray device and system that mixes the powder and accelerant upstream of the spray nozzle.

One or more of these and/or other objects, features, or advantages of the present invention will become apparent from the specification and claims that follow.

SUMMARY

One embodiment provides a device and system for cold spraying. The cold spray system includes a spray nozzle having an input side and a discharge side. A gas flowpath, a powder flowpath, and a confluence of the gas flowpath and the powder flowpath provide a gas-powder mixture. A gas-powder mixture flowpath between the confluence and the nozzle carry the gas-powder mixture to the input side of the spray nozzle.

Another embodiment provides a cold spray device. A gas-powder mixture is discharged from a nozzle body. A gas-powder mixture input side on the nozzle body is adapted for downstream communication with a gas-powder mixing manifold. The nozzle body may include a gas-powder mixture output side. A gas-powder flowpath may be in communication with the input side and output side. The gas-powder mixture includes a gas temperature and a powder temperature, wherein the powder temperature is generally at the gas temperature at the input side. In a preferred aspect, the cold spray device includes a gas-powder line housing the gas-powder flowpath, wherein the gas-powder line is connected between the inlet on the input side and a spray nozzle on the output side.

Yet another embodiment provides a cold spray system. The cold spray system includes a flowpath having an inlet adapted for receiving communication with two or more inputs and an outlet adapted to discharge at least the two or more inputs. A discharge nozzle may be included in the flowpath at the outlet. A confluence in the flowpath may be included at the inlet for combining the two or more inputs. A nozzle body may be configured to house the discharge nozzle separate and downstream from the confluence. In a preferred aspect, a single line houses the flowpath between the confluence and the nozzle body.

