A device that uses nanosecond laser to precisely control the temperature of 3D printing polymer materials

Abstract

The invention discloses a high-molecular material 3D printing device applying nanosecond lasers to accurately control temperatures. The device includes two laser devices, a beam expander, a light beam scanning controller, a preheating chamber, a powder feeding device, a working platform, two temperature sensors and a control module. Through use of the device and in a laser sintering type printing technological process, energy emitted by the laser devices in unit time can be accurately controlled through controlling increase or decrease of the repetition frequency of pulses outputted by a pulse laser, so that a high-molecular material powder is allowed to maintain in a sufficient accuracy range in preheating and sintering processes, the temperature gradient of the interior of the material is uniformly distributed, defects of the interior of a molded workpiece are greatly reduced, moreover, the workpiece molding quality is better, and higher machining accuracy is maintained.

Description

technical field [0001] The invention relates to 3D printing technology, in particular to a device for 3D printing polymer materials using nanosecond laser to precisely control temperature. Background technique [0002] 3D printing is a kind of rapid prototyping technology. This technology is based on digital model files, and the complex 3D shapes that need to be formed are processed into simple 2D cross-section combinations by computer, and bondable materials such as metal or plastic are used to deposit them layer by layer along a certain direction to form a series of 2D cross-sections Layers, and then use some methods to make the cross-sectional layers bond to each other and accumulate into the required 3D workpiece. Compared with traditional manufacturing technologies, 3D printing has the advantages of manufacturing complex items without increasing costs, no assembly, flexible and portable, multi-material combination, reduced waste raw materials, and accurate physical rep...

AI Technical Summary

Problems solved by technology

[0004] However, the current laser sintering 3D printing technology has great limitations. For the printing process of polymer materials, when the laser is irradiated and sintered, the temperature often fluctuates up and down, which is difficult to control accurately.

If the temperature is too low, the laser cannot fully melt the material; if the temperature is too high, the polymer material will degrade and cannot be used effectively

This will lead to poor molding quality of the workpiece and reduced machining accuracy

In the preheating stage before the material powder is sintered, if the preheating temperature cannot be accurately controlled, it will cause large fluctuations in the temperature difference from the sintering time, resulting in an uneven distribution of the temperature gradient inside the material, which in turn makes the molding The workpiece contains certain defects, such as cracks, shrinkage cavities, etc.

The above two limitations will cause the final finished workpiece to be far from the actual requirements of the product in terms of mechanical, electrical, and mechanical properties.

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