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Online real-time monitoring method of 3D printing process based on positron annihilation

A positron annihilation and 3D printing technology, applied in the field of 3D printing, can solve the problems of low imaging efficiency, high radiation hazards, and high cost, and achieve high detection accuracy, high imaging efficiency, and good imaging quality

Active Publication Date: 2022-08-05
NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] At present, the γ-photon 3D imaging detection technology based on positron annihilation is relatively mature in the field of clinical disease diagnosis, but few scholars have studied it in the field of industrial detection. There are many, its industry standards are not perfect, and the evaluation of processing technology has not formed a unified technical standard
Non-destructive testing methods for 3D printed specimens usually use X-ray testing, electron microscope monitoring, etc. In actual testing, this type of method has disadvantages such as high cost, high radiation hazards, only detection of shallow surface defects, and inability to monitor online in real time.
The industrial CT detection process is planar asynchronous imaging, the imaging efficiency is low, the test time is long, and online real-time detection cannot be realized
Optical microscope and transmission electron microscope cannot detect the inner cavity of parts; the detection depth of X-ray scattering can reach centimeter level, but the resolution of defect size cannot reach nanometer level

Method used

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  • Online real-time monitoring method of 3D printing process based on positron annihilation
  • Online real-time monitoring method of 3D printing process based on positron annihilation
  • Online real-time monitoring method of 3D printing process based on positron annihilation

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Experimental program
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Effect test

Embodiment 1

[0024] When the printing material is PLA, the online real-time monitoring method of the 3D printing process based on positron annihilation includes the following steps:

[0025] Step 1, the H-containing accelerator produced by the accelerator 18 F of H 2 18 O solution in N 2 Under flow transport, positron nuclides 18 The activity of F was 0.1 mCi, and it was passed through a QMA solid phase extraction column (10 mL of NaHCO with a concentration of 0.5 mol / L). 3 Rinse, then rinse with 20mL of ultrapure water), H 18 F was adsorbed on the QMA solid phase extraction column. After the adsorption was completed, 1.5 mL of K222 / K was used. 2 CO 3 The eluent was eluted to the reaction tube, the mixture was heated to 105°C by a heater, and the solvent was evaporated to dryness under nitrogen flow;

[0026] In step 2, 2 mL of anhydrous acetonitrile was added again, the solvent was evaporated to dryness at 105 ° C under the action of nitrogen flow, the cooling fan was turned on to ...

Embodiment 2

[0030] When the printing material is metallic Fe, the online real-time monitoring method of 3D printing process based on positron annihilation includes the following steps:

[0031] Step 1, select positron nuclides 127 Xe, generating a positron nuclide with an activity of 1 mCi 127 Xe;

[0032] Step 2, use positron nuclides 127 Xe makes positrons uniformly and continuously generated inside the 3D printed object during the 3D printing process;

[0033] Step 3: Build a BGO annular array detector with a diameter of 100 cm, and fix the 3D printer inside the γ-photon annular array detector to collect the γ-photon data generated by positron annihilation that conforms to the detection in real time;

[0034] Step 4: Establish a mathematical model of the correspondence between the concentration distribution of positron nuclides and image pixels, and use the OSEM mathematical algorithm to obtain a 3D image of the distribution of printing materials during the printing process of the 3D ...

Embodiment 3

[0036] When the printing material is polypropylene resin, the online real-time monitoring method of 3D printing process based on positron annihilation includes the following steps:

[0037] Step 1, select positron nuclides 55 Fe, forming a positron nuclide with an activity of 0.5 mCi 55 Fe;

[0038] Step 2, use positron nuclides 55 Fe makes positrons uniformly and continuously generated inside the 3D printed object during the 3D printing process;

[0039] Step 3: Build an LSO ring array detector with a diameter of 75cm, and fix the 3D printer inside the γ photon ring array detector to collect the γ photon data generated by the positron annihilation that conforms to the detection in real time;

[0040] Step 4: Establish a mathematical model of the correspondence between the positron nuclide concentration distribution and the image pixels, and use the MLEM mathematical algorithm to obtain a 3D image of the distribution of printing materials during the printing process of the ...

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Abstract

The invention discloses an online real-time monitoring method for a 3D printing process based on positron annihilation, comprising the following steps: a. selecting a type of positron nuclide to generate an active positron nuclide; b. using the positron nuclide Make positrons uniformly and continuously generated inside the 3D printed object; c. Fix the 3D printer inside the γ-photon ring array detector to collect the γ-photon data generated by the annihilation of positrons that conform to the detection in real time; d. Establish the concentration of positron nuclides The mathematical model of the correspondence between the distribution and the image pixels uses the MLEM or OSEM mathematical algorithm to obtain a 3D image of the distribution of the printing material during the printing process of the 3D printer. The present invention has the advantages of spatial synchronous imaging, high imaging efficiency, short test time, good imaging quality, and no radiation hazards; the present invention reconstructs a 3D image of the spatial state distribution of the printing material through a mathematical algorithm, and intuitively and visually achieves the purpose of online real-time monitoring of the 3D printing process .

Description

technical field [0001] The invention belongs to the technical field of 3D printing, in particular to an online real-time monitoring method for a 3D printing process based on positron annihilation. Background technique [0002] The field of γ-photon three-dimensional imaging based on positron annihilation is the clinical application of PET (positron emission tomography) in biomedicine. Habib Zaidi, a scholar at the University of Geneva, conducted a study on the improvement of the spatial resolution of PET instruments in 2007, and believed that PET / CT could replace pure PET. In 2008, he believed that PET / MRI has higher imaging accuracy than PET / CT. At the same time, Martin S Judenhofer of the University of California has been studying how PET detectors evaluate the performance of their data acquisition boards during high-speed sampling since 2004. In 2008, he published a paper in Nature Medicine, confirming that PET / MRI is the study of biological function and A new method in ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01T1/36
CPCG01T1/36
Inventor 肖辉赵敏刘兼唐姚敏陈皓梁欢
Owner NANJING UNIV OF AERONAUTICS & ASTRONAUTICS