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CN-122008537-A - Method for preparing macro-micro directional structure by variable-diameter fused deposition

CN122008537ACN 122008537 ACN122008537 ACN 122008537ACN-122008537-A

Abstract

The invention discloses a method for preparing a macro-micro directional structure by variable-diameter fused deposition, belonging to the technical field of additive manufacturing. Adding part of titanium trisulfide nanorods into polyether-ether-ketone powder for high-energy ball milling, adding residual filler and antistatic agent for low-energy ball milling, carrying out multi-stage time sequence blending to obtain composite powder, carrying out segmented heating and melt extrusion and gradient slow cooling shaping by a screw, matching with laser to obtain a prefabricated wire by regulating extrusion parameters in a closed loop manner in an online diameter measuring manner, finally controlling the ratio V p/f of printing speed to wire feeding speed in the shaping process, orderly stacking and depositing a fused deposition path along a single direction, and preparing the macro-micro directional structure with the orientation of the titanium trisulfide nanorods consistent with the printing path direction of the polyether-ether-ketone. The method is simple to operate, flexible and controllable in process, and the prepared titanium trisulfide nanorod/polyether-ether-ketone macro-micro directional structure has the advantages of good directionality, high heat conductivity, strong electric conductivity, good wear resistance, high tensile strength and the like, and can be widely applied to the fields of aerospace, electronic chips, medical appliances, transportation and the like as a supporting structure.

Inventors

  • LI YANG
  • MI CHENGJI
  • XU LIANG

Assignees

  • 湖南工业大学

Dates

Publication Date
20260512
Application Date
20260413

Claims (11)

  1. 1. The method for preparing the macro-micro directional structure by variable-diameter fused deposition is characterized by comprising the following steps of: (1) The multistage sequential powder blending is that firstly, part of titanium trisulfide nano rods and all polyether-ether-ketone powder are subjected to high-energy ball milling under the protection of low-temperature inert gas, then the rest of titanium trisulfide nano rods are added into the premix, and then nano silicon dioxide antistatic agent is added for low-energy ball milling, so that composite powder is obtained; (2) Feeding the composite powder obtained in the step (1) into an inlet of a screw extruder, carrying out sectional heating melting and gradient slow cooling shaping to obtain a prefabricated wire, arranging a laser on-line diameter measuring instrument at an outlet, measuring the diameter of the prefabricated wire in real time, and carrying out closed loop feedback adjustment on technological parameters of the extruder; (3) Feeding the prefabricated wire material obtained in the step (2) into a melting cavity of a printer, and dynamically regulating and controlling the ratio V p/f of the printing speed to the wire feeding speed in the forming process to obtain a molten deposition path with the characteristics of variable diameter and variable section; (4) And (3) preparing a macro-micro directional structure, namely regulating and controlling the ratio V p/f to be larger than 1 in the deposition process of the step (3), orderly stacking and depositing the fused deposition path along a single direction, and preparing the macro-micro directional structure with the orientation of the titanium trisulfide nano rod being consistent with the direction of the polyether-ether-ketone printing path.
  2. 2. The method according to claim 1, wherein in the step (1), the average particle diameter of the polyetheretherketone powder is 40 μm, the average diameter of the titanium trisulfide nanorods is 6 μm, the aspect ratio is 10:1 to 20:1, and the average particle diameter of the nanosilica is 30 nm.
  3. 3. The method of claim 2, wherein in the step (1), the mass ratio of the polyether-ether-ketone to the titanium trisulfide nanorods is 90:10-70:30, 25% of the total mass of the titanium trisulfide nanorods is added into the polyether-ether-ketone powder during premix, and the added nano silicon dioxide antistatic agent accounts for 0.3% of the total powder mass.
  4. 4. The method of claim 3, wherein in the step (1), the temperature is controlled to be-5-15 ℃, ball milling is performed under the protection of argon inert gas, the high-energy ball milling rotating speed is 450-500 r/min, the ball mass ratio is 12:1, the total ball milling time is 35-45 min, the low-energy ball milling rotating speed is 150-200 r/min, the ball mass ratio is 6:1, and the total ball milling time is 120-150 min.
  5. 5. The method of claim 1, wherein in the step (2), 4-6 independent temperature control areas are arranged along the extrusion direction of the screw extruder, the temperature is gradually increased from 350-360 ℃ of the feeding section to 390-400 ℃ of the melting section and then reduced to 360-365 ℃ of the outlet section, the rotating speed of the screw is 30-100 r/min, and after the melt is extruded from the outlet, 3-section slow cooling channels of a high-temperature preheating section at 60-80 ℃, a medium-temperature shaping section at 40-60 ℃ and a low-temperature cooling section at 20-40 ℃ are adopted for cooling shaping.
  6. 6. The method of claim 5, wherein in step (2), the diameter fluctuation of the pre-manufactured wire is controlled to be less than + -0.02 mm by a closed loop, and the process parameters of the closed loop feedback adjustment extruder include screw speed, extrusion pressure and extrusion speed.
  7. 7. The method of claim 1, wherein in the step (3), the regulation and control method of V p/f includes two modes, that is, keeping the feeding speed constant, changing the printing speed to realize the regulation and control of the ratio V p/f , and keeping the printing speed constant, and changing the feeding speed to realize the regulation and control of the ratio V p/f .
  8. 8. The method of claim 7, wherein in step (3), a fused deposition path greater than the diameter of the nozzle is prepared when V p/f is changed to be less than 1, and a fused deposition path less than the diameter of the nozzle is prepared when V p/f is changed to be greater than 1.
  9. 9. The method according to claim 1, wherein in step (4), the directional distribution of the titanium trisulfide nanorods is controlled by controlling 3 V p/f 4, Wherein the included angle between the long axis direction of the titanium trisulfide nano rod and the deposition path direction is smaller than 8 degrees.
  10. 10. The method of claim 9, wherein in step (4), the number of layers stacked in a single direction is not less than 5.
  11. 11. The method according to claim 1, wherein the macro-micro oriented structure prepared by the method according to any one of claims 1 to 10 is used for controlling the anisotropy of the heat conductivity, the electrical conductivity, the wear resistance and the mechanical properties of the manufactured piece.

Description

Method for preparing macro-micro directional structure by variable-diameter fused deposition Technical Field The invention belongs to the technical field of additive manufacturing, and particularly relates to a method for preparing a macro-micro directional structure by variable-diameter fused deposition. Background The polyether-ether-ketone as a high-performance special engineering plastic has the advantages of excellent high temperature resistance, high mechanical strength, good biocompatibility, corrosion resistance and the like. The titanium trisulfide nano rod is used as a one-dimensional reinforcing phase filler, and has excellent specific strength, fatigue resistance, higher heat conductivity and electric conductivity in the axial direction. The polyether-ether-ketone and titanium trisulfide nano rods are compounded together, so that the respective advantages can be fully exerted, the performance complementation is realized, and the comprehensive performance of the material is better. However, the titanium trisulfide nanorods are distributed in a disordered state in the polyether-ether-ketone matrix, so that the reinforcing potential of the axial ultrahigh performance of the titanium trisulfide nanorods is difficult to fully develop, and the further improvement of the performance of the composite material is severely restricted. The macro-micro directional structure with the consistent distribution orientation of the titanium trisulfide nano rods and the printing path direction of the polyether-ether-ketone is prepared, so that the anisotropic enhancement effect of the titanium trisulfide nano rods in the polyether-ether-ketone matrix is fully exerted, and a three-dimensional continuous bearing framework is constructed, so that the performances of the part such as heat conductivity, electric conductivity, wear resistance, tensile strength and the like in a specific direction are remarkably improved. The existing variable-diameter 3D printing technology realizes the variable-diameter printing effect by changing the size of the nozzle, but the method cannot prepare a printing path with continuously variable deposited wire diameter, and when the size of the nozzle is too small, the melt is easy to block the nozzle, so that the printing quality and the forming reliability are affected. Therefore, there is a need for a method for preparing macro-micro oriented structures by variable diameter fused deposition without changing the diameter of the nozzle, so as to fully release the reinforcing potential of the titanium trisulfide nanorods and further improve the comprehensive performance of the composite material. Disclosure of Invention In order to achieve the purpose, the invention provides the following technical scheme that the method for preparing the macro-micro directional structure by variable-diameter fused deposition comprises the following steps: (1) The multistage sequential powder blending is that firstly, part of titanium trisulfide nano rods and all polyether-ether-ketone powder are subjected to high-energy ball milling under the protection of low-temperature inert gas, then the rest of titanium trisulfide nano rods are added into the premix, and then nano silicon dioxide antistatic agent is added for low-energy ball milling, so that composite powder is obtained; (2) Feeding the composite powder obtained in the step (1) into an inlet of a screw extruder, carrying out sectional heating melting and gradient slow cooling shaping to obtain a prefabricated wire, arranging a laser on-line diameter measuring instrument at an outlet, measuring the diameter of the prefabricated wire in real time, and carrying out closed loop feedback adjustment on technological parameters of the extruder; (3) Feeding the prefabricated wire material obtained in the step (2) into a melting cavity of a printer, and dynamically regulating and controlling the ratio V p/f of the printing speed to the wire feeding speed in the forming process to obtain a molten deposition path with the characteristics of variable diameter and variable section; (4) And (3) preparing a macro-micro directional structure, namely regulating and controlling the ratio V p/f to be larger than 1 in the deposition process of the step (3), orderly stacking and depositing the fused deposition path along a single direction, and preparing the macro-micro directional structure with the orientation of the titanium trisulfide nano rod being consistent with the direction of the polyether-ether-ketone printing path. Further, in the step (1), the average particle size of the polyether-ether-ketone powder is 40 mu m, the average diameter of the titanium trisulfide nano-rod is 6 mu m, the length-diameter ratio is 10:1-20:1, the average particle size of the nano-silicon dioxide is 30 nm, the mass ratio of the polyether-ether-ketone to the titanium trisulfide nano-rod is 90:10-70:30, 25% of the total mass of the titanium trisulfide nano-rod is added into the polyet