Method for conducting melting forming through laser powder scanning

Abstract

The invention provides a method for conducting melting forming through laser powder scanning. The method comprises the following steps that a computer conducts partition processing on a slice section corresponding to each slice, and each slice section is divided into a regular area and an edge curve area; the computer controls a regular light spot laser beam generated by a first laser source to act on the regular areas and controls a changeable-shape light spot laser beam generated by a second laser source to act on the edge curve areas once, metal powder is molten, and target slice sections are formed; and then, a layer of metal powder is laid again on the upper surface of each formed target slice section, the step is repeated, overlaying is conducted layer by layer, forming is conducted in an accumulation mode until the whole forming process is completed, and the formed part is obtained. The method has the advantages that the two beams of laser are adopted for scanning different forming areas in parallel, so that the laser scanning speed is high, laser scanning energy is uniform, thermal stress of the whole part is small, and the part is not liable to deformation.

Description

technical field [0001] The invention belongs to the technical field of laser melting and forming, and in particular relates to a method for melting and forming laser scanning powder. Background technique [0002] The rapid prototyping technology of selective laser melting (Selective Laser Melting, SLM) metal powder can directly form metal parts that are close to complete density. Especially suitable for the manufacture of complex structural parts. [0003] The SLM system is mainly composed of a powder feeding system, a laser scanning system, a powder spreading system, a forming chamber, a control system that controls the operation of the entire equipment, and corresponding programs. Its working principle is: (1) First, input the CAD three-dimensional model of the part into the computer; ( 2) The computer slices and layers the CAD 3D model of the molded part to obtain the scanning path corresponding to each slice; (3) The computer controls the laser scanning system according...

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Problems solved by technology

[0005] This working method of single-beam laser scanning mainly has the following disadvantages: a single-beam laser is required to scan the entire slice section point by point. On the one hand, it takes a long time and reduces the forming efficiency; During the process of laser traversing different positions of the scanning section, the temperature field of the section changes drastically and the uniformity of the temperature field is poor. The significant temperature difference between the material and the environment after heating will increase the thermal stress of the material, making it prone to warping and deformation during the manufacturing process of the part. crack

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