Three-dimensional printing system

Abstract

The invention relates to a three-dimensional printing system, in particular to a three-dimensional printing system which is more flexible than an existing laser coaxial wire feeding three-dimensional printing technology and has a non-contact forging function, and belongs to the technical field of additive manufacturing. Compared with an existing coaxial wire feeding three-dimensional printing technology based on laser heating, the coaxial wire feeding three-dimensional printing method has numerous beneficial effects, for example, a flexible heating strategy can be achieved; printing of finer structures is supported; the molten raw material which is just deposited can be prevented from being excessively heated; the effects of emphasizing metal grains and stirring a molten pool in the three-dimensional printing process can be achieved, an area where a molten raw material is about to be deposited can be preheated in advance, hot cracks can be inhibited, and parts with higher comprehensive performance can be obtained; laser cleaning can be integrated in the three-dimensional printing process, and metal three-dimensional printing is carried out on the premise that protective gas is not used in the air; and the method has extremely high fault-tolerant capability on the mechanical assembly precision of a laser light path. The invention has prominent substantive progress.

Description

technical field [0001] The invention relates to a three-dimensional printing system, in particular to a three-dimensional printing system which is more flexible than the existing laser coaxial wire feeding three-dimensional printing technology and has a non-contact forging function, and belongs to the technical field of additive manufacturing. Background technique [0002] 3D printing, also known as additive manufacturing, is a broad category of advanced manufacturing technologies. The raw materials used in 3D printing come in various forms, such as liquids, solid powders, granules, wires, rods, wires, etc. Among them, wire or wire raw materials are often cheaper than powder raw materials, and are easy to store, safer and environmentally friendly. In the existing 3D printing technologies that use lasers as heating sources and wire or wire as raw materials, there are two types of technologies: "paraxial wire feeding" and "coaxial wire feeding". For example, the technical sol...

AI Technical Summary

Problems solved by technology

However, the thermal current generated at the solid / liquid interface is weak, unstable, and the duration of the current is short, the electromagnetic effect that can be generated is weak, and the viscosity of the metal melt is high, and the response to the force of high-speed changes is slow, leading to this technology. The modulation effect on the grain is not significant, especially when the heat continues to accumulate on the printed part as the printing process continues, and the base temperature of the part increases, resulting in a decrease in the temperature gradient at the solid / liquid interface of the molten pool. The intensity of the thermal current will be further reduced, resulting in further weakening of the interaction between the thermal current and the magnetic field; at the initial moment of the molten pool, the temperature difference at the solid / liquid interface reaches a peak value, but as the molten pool solidifies, the area where the molten pool has just solidified and the area that has not yet solidified The temperature difference between the solidified areas is small, the thermal current generated at the solid / liquid interface is weaker, and the internal temperature difference in the unsolidified area inside the molten pool is smaller, and it is more difficult to generate thermal current; relying on the thermal current generated at the solid / liquid interface and The external magnetic field interacts to modulate the grains. In addition to the insignificant effect, there is also the problem of uneven distribution of the intensity of the action.

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