In-situ energy controlled selective laser melting device and method

Abstract

The invention discloses an in-situ energy controlled selective laser melting device and method. According to the in-situ energy controlled selective laser melting device and method, a path of synchronously scanned flat-topped large light spot is additionally arranged, energy below a powder melting point threshold value is provided, the powder preheating/solidification rate is regulated and controlled, formed metal is annealed, the temperature gradient is reduced, and the forming internal stress is reduced, so that behaviors such as deformation and cracking caused by stress are reduced; and meanwhile, due to the fact that energy input lower than the melting point threshold value of a material is provided, material melting can be completed only by providing low energy input for original SLMsmall light spots, and the adverse conditions of molten pool splashing, micro air hole generation and the like are improved. In addition, time and space distribution of laser energy is realized basedon an in-situ energy control mode. Therefore, according to the method, defects generated in the part forming process are effectively reduced, meanwhile, the solidification rate is controlled, the structure evolution is regulated and controlled, and the method plays an important role in stably and efficiently forming high-performance parts and promoting wide application of the additive manufacturing technology.

Description

technical field [0001] The invention belongs to the technical field of additive manufacturing, and in particular relates to an in-situ energy-controlled laser selective melting device and method. Background technique [0002] Selective Laser Melting (SLM) is an additive manufacturing technology that uses high-energy lasers to rapidly melt and solidify irradiated powders to achieve layer-by-layer molding of molded parts. In the process of selective laser melting and molding, the micro-melting pool formed by the powder bed under the irradiation of Gaussian distributed laser spot is easy to cool and solidify due to the uneven heat distribution (uneven heat transfer process) and the resulting imbalance in the mass transfer process. The internal structure of the final structure generates great thermal stress, which causes stress deformation, cracking and other problems in the formed parts, and even leads to the failure of the forming process. In addition, the molten pool formed ...

AI Technical Summary

Problems solved by technology

However, the way to control the laser energy by only changing the shape of the spot is still relatively simple and the range is limited.

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