Method for inhibiting hole defects of uniform metal microdroplet jet 3D printing

Abstract

The invention provides a method for inhibiting hole defects of uniform metal microdroplet jet 3D printing. The method comprises the steps of printing initialization, printing raw material supply, induction heater starting, heating plate starting, on-demand uniform metal microdroplet generator starting, metal microdroplet deposition and the like. According to the method, a new thought that the electric field induction effect is adopted to inhibit the hole defects inside a uniform metal microdroplet jet printed piece is put forward, an electric field is utilized to trigger the bottoms of metal microdroplets to generate Taylor cones, the center areas of the bottoms of the metal microdroplets can make contact with a deposition base body in advance, and the gas entrapment behavior in the microdroplet collision process is fundamentally inhibited; and flow filling of the metal microdroplets in the surface gap area of a deposition solidification layer is promoted through the electric field guiding attraction effect, the effective inhibition of the hole defects inside the printed piece is achieved, and the technical bottleneck that the density of the uniform metal microdroplet jet printed piece cannot be easily further improved is expected to be broken through.

Description

technical field [0001] The invention relates to the technical field of uniform metal droplet jetting 3D printing, in particular to a method for suppressing hole defects in uniform metal droplet jetting 3D printing. Background technique [0002] The additive manufacturing technology based on uniform metal droplet injection is an emerging technology different from traditional metal 3D printing. It controls the parameters such as pulse pressure and vibration waveform to make the molten metal spray form micron to submillimeter uniform Droplets, and then precisely control the coordination and matching between the three-dimensional movement of the deposition substrate and the on-demand ejection of the droplets, and realize the point-by-point, line-by-line, and layer-by-layer printing of metal droplets according to the preset scanning trajectory, and finally form the target three-dimensional structure. Uniform metal droplet jetting 3D printing technology has the advantages of high ...

AI Technical Summary

Problems solved by technology

However, this method is mainly based on the influence of process parameters on the macroscopic density of printed parts, and has not considered the detailed formation process of hole defects in this technology and its potential influencing factors

[0004] In the process of uniform metal droplet jet printing, the entrainment behavior of droplet collision is the physical essence of droplet collision dynamics. The local rapid solidification of metal droplets and the high resistance caused by strong melt Marangoni-driven flow Under the combined action, it is difficult for the air bubbles involved in the bottom of the metal droplets to be discharged under the buoyancy drive, so it is difficult to effectively suppress the pore defects formed by the entrained gas by optimizing the control process parameters; secondly, the continuous accumulation of multiple metal droplets The surface of the deposited layer usually spontaneously forms a "shell"-shaped uneven characteristic morphology. When the molten metal flows into the gaps on the surface of the deposited layer, due to the capillary force of the liquid metal fluid, surface tension and the filling area gas The balance between the reverse resistance, the flow filling process usually has an infiltration limit, that is, it is difficult to completely fill the tiny voids in the interface region of the sediment layer solely relying on the spreading flow of metal droplets

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