A device and method for coaxial double-beam laser preheating and slow cooling stress release

Abstract

The invention discloses a coaxial double-beam laser preheating forming slow cooling stress sustained-release device and method. The device comprises beam expanding lenses, collimation convex lenses and focusing convex lenses, wherein the beam expanding lenses, the collimation convex lenses and the focusing convex lenses are sequentially arranged in the emergent direction of laser beams, the beam expanding lenses are used for conducting beam expanding on the laser beams, the collimation convex lenses are used for outputting the laser beams subjected to beam expanding in parallel, and the focusing convex lenses are used for receiving the parallel laser beams and outputting coaxial double beams. Planes A used for outputting the laser beams in parallel so as to form large light spots A are arranged at the convex face central positions of the focusing convex lenses, the convex face portions of the focusing convex lenses enable the laser beams to be focused so as to form small light spots B, and the light spots A and the light spots B are coaxial. By the adoption of the device and method, the convex lenses and concave lenses are combined for use, so that the coaxial double beams with the sizes of the light spots capable of being adjusted are generated, the large light spots are used for preheating and slowly cooling metal powder, the laser absorptivity of materials is improved, stress is released, the temperature gradient is lowered, and the tissue defects such as segregation, cracks and holes are reduced; the small light spots are used for forming, the focusing performance is good, energy is stable, and the forming efficiency, precision and quality are improved.

Description

technical field [0001] The invention belongs to the field of additive manufacturing, and in particular relates to a coaxial double-beam laser preheating forming slow-cooling stress-releasing device and method in laser selective melting and forming. Background technique [0002] Selective Laser Melting (SLM) technology is a typical representative of additive manufacturing. It transforms the traditional three-dimensional manufacturing process into a planar manufacturing-cumulative superposition process, and realizes the manufacture of three-dimensional complex precision parts through layer-by-layer melting of powder. Because the powder is in a static state, the auxiliary support structure can be designed and manufactured, so it is suitable for the manufacture of metal parts with almost any complex shape, and can be widely used in aerospace, automotive, mold, medical and other industries. [0003] However, in the laser forming process, since the high-energy laser provides a hea...

AI Technical Summary

Problems solved by technology

At present, in the laser selective melting forming equipment, there is no report on the use of double-beam laser preheating and slow cooling.

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