3D printing device and printing method for integrated manufacturing of functionally graded materials and structures

Abstract

The invention discloses a 3D printing device and a printing method integrated with functional gradient materials and structures. The 3D printing device includes: a three-dimensional mobile support; a printing nozzle installed on the three-dimensional mobile support, including a stepping motor, a stirring paddle, and a casing and the nozzle, the stepping motor is arranged at the end of the housing, one end of the stirring paddle is connected to the output shaft of the stepping motor through a coupling, and the other end extends to the mixing chamber inside the housing, and the output shaft of the stepping motor It is sealed with the casing; the nozzle and the stepping motor are installed at the other end of the casing oppositely, and a control valve is set on the material flow path between the nozzle and the mixing chamber; printing materials are arranged on the side wall of the mixing chamber The I inlet and the printing material II inlet are respectively connected to the printing material I feeding pump and the printing material II feeding pump; the side wall of the housing between the mixing chamber and the stepping motor is provided with an opening of the air passage I and an air passage II The openings are respectively connected with the air source and the vacuum pump.

Description

technical field [0001] The invention belongs to the technical field of additive manufacturing and functionally graded material / structure manufacturing, and in particular relates to a 3D printing device and a printing method for the integrated manufacture of functionally graded materials and structures. Background technique [0002] The disclosure of information in this Background section is only for enhancement of understanding of the general background of the invention and should not necessarily be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person of ordinary skill in the art. [0003] Functionally graded material (Functionally Gradient Material, referred to as FGM) refers to the use of advanced composite technology in the preparation process of the material, so that the microscopic elements (including material components and microstructure) of the material are continuous in a specific direction (or It ...

AI Technical Summary

Problems solved by technology

[0007] According to the existing research results and information that have been published at home and abroad, the 3D printing technologies and processes that have been proposed for the manufacture of functionally graded materials / structural parts mainly include: directed energy deposition (LENS), laser cladding, and fused deposition modeling (FDM). , polymer injection (Polyjet), powder bed fusion, etc., but, according to the research of the inventor, it is found that these existing 3D printing technologies still have many defects and deficiencies when manufacturing functionally graded materials / structural parts: (1) Inhomogeneous mixing of ingredients

However, in the mixing process of liquid and solid powder, there are the following problems: (1) in the mixing process, the powder is easy to agglomerate and difficult to disperse, which is a common problem in existing solid-liquid mixing; (2) if the viscosity of the liquid is too high, Air will be brought in during the mixing process, prone to bubbles, and it is difficult for solid powder to mix evenly in the liquid; (3) Solid-liquid mixed materials with different ratios can be fed, mixed and extruded during the printing process. The whole process takes a short time and requires fast response

For example, for PDMS-based functionally graded materials, PDMS has a high viscosity, and it is difficult for solid nanoparticles to mix uniformly in PDMS liquid, and bubbles are prone to appear during the mixing process. The uneven distribution of solid nanoparticles and the generated bubbles will seriously affect 3D printing. product quality, etc.

For the field of flexible electronics, various single-material flexible substrates widely used at present are increasingly unable to meet the needs of practical engineering applications.

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