Thin-beam laser melting deposition additive manufacturing method and laser processing head used therefor

Abstract

The invention discloses a method for manufacturing thin-beam laser melting deposition addition materials and a laser machining head used in the method. The method comprises that a parallel collimatedlaser is converted into a circular annular laser beam; the circular annular laser beam is then converted into two semicircular annular laser beams with gaps and then restored back to the circular annular laser beam; the circular annular laser beam is converged to form a focusing light spot near the surface of a substrate; the powder is laterally fed from the gaps and then is accelerated to be ejected from a nozzle under the action of jet flow energy; the ejected powder meets the focused spot near the surface of the substrate; and the powder and the substrate surface are heated to fully or semi-molten states so that the powder can achieve liquid or solid phase deposition on the surface of the substrate. In practice, the ejected powder and the focusing light spot continuously move together relatively to the surface of the substrate, the powder is deposited layer by layer and thickened, and a part with a preset shape is finally formed and manufactured. According to the method, the central-coaxial powder feeding is achieved, a laser light path is not shielded, and the purpose of high-speed laser cladding or spraying with low powder splashing is achieved.

Description

technical field [0001] The invention relates to a thin-beam laser melting deposition additive manufacturing method and a laser processing head used in the manufacturing method, belonging to the technical field of laser additive manufacturing. Background technique [0002] Laser additive manufacturing (LAM) technology is a new type of manufacturing technology that uses laser as the energy source, based on the principle of layered manufacturing, and adopts the method of accumulating materials layer by layer to directly manufacture digital models into physical parts. Laser has the characteristics of high energy density, which can realize the manufacture of difficult-to-machine metals and non-metallic materials such as plastics and ceramics. At the same time, laser additive manufacturing technology also has the advantage of not being limited by the structure of parts, and can be used for complex structures, difficult processing and thin-walled materials. Manufacturing of parts. ...

AI Technical Summary

Problems solved by technology

The powder feeding method of the center beam usually has the following deficiencies: ①Because the powder slantly converges to the focus of the spot and then disperses again, the action range with the laser is small, and the degree of heating is different, resulting in serious powder splashing and low utilization rate; ②Due to the diameter of the powder spot It directly determines the size of the deposition spot (welding bead), and the lateral coaxial method requires high coaxiality accuracy of the laser processing head, resulting in a small adjustable range of powder spot diameter, which is difficult to reduce to below the millimeter level, which in turn leads to The deposition spot (weld bead) is wide, and the improvement of forming accuracy is limited

The current laser melting deposition additive manufacturing technology with central coaxial powder feeding mostly uses wire or metal powder as raw materials, but the width of deposited spots is mostly several millimeters or even tens of millimeters, which is not suitable for high-precision additive manufacturing of parts.

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