| 摘要 |
A nozzle particularly suited to direct metal deposition increases the quality of metallurgical properties, enhances deposition rate and process efficiency, and improves surface quality, reliability, and maintainability. The preferred embodiment includes a body having a central axis and a distal end terminating in a distal tip through which a laser beam emerges. A gas-carried powder feed path terminates in one or more powder outlets arranged in a first concentric ring surrounding the laser beam, and a shaping-gas inlet and one or more shaping-gas outlets are arranged in a second concentric ring surrounding the laser beam. The internal geometry of the body is such that the laser beam, powder, and shaping gas all converge substantially within a localized region of a workpiece spaced apart from the distal tip at a working distance. The assembly preferably further includes a powder splitter that evenly distributes powder flow into a plurality of tubes within the body, and an inner tip surrounding the laser beam, the distal tip including conical end against which the powder is urged prior to exiting the body to assist in directing the powder to the localized point of the workpiece. The shaping gas preferably exits the body in a laminar flow condition. At least a portion of the distal tip is adjustable to alter the working distance to the workpiece.
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