Screening method for 3D printing titanium alloy porous scaffold

Abstract

The invention belongs to the field of titanium alloys, and particularly relates to a screening method of a 3D printed titanium alloy porous scaffold, which comprises the following steps: performing 3D printing on titanium alloy powder to obtain different porous scaffolds, and then sequentially performing optical microscope observation, micro computer tomography, static compression experiment and fatigue test on the porous scaffolds to obtain the 3D printed titanium alloy porous scaffold. By adopting the method provided by the invention, not only can the porous scaffold with high pore connectivity and high strength be quickly obtained so as to meet the long-term safe use requirement and the osteogenesis promotion requirement of the porous implant prosthesis, but also the mechanical properties of more different porous units can be predicted; the non-molten powder and impurity components are effectively prevented from remaining on the surface of the 3D printing titanium alloy porous scaffold, and the method is also suitable for screening of most metal porous scaffolds and is wide in application range and high in practicability.

Description

Technical Field

[0001] The present invention belongs to the technical fields of 3D printing and medical devices, and particularly relates to a screening method for 3D printed titanium alloy porous scaffolds. Background Art

[0002] Traditional implants are made of solid titanium alloy. Not only is the elastic modulus much greater than that of the host bone, which easily causes stress shielding, leading to bone resorption and osteoporosis, but also the weight is relatively large, bringing unnecessary burden to patients. However, due to the rapid development of 3D printing technology, the implant can be made porous. While minimizing the weight of the implant, its strength is not reduced, enabling its mechanical properties to achieve good matching with the host bone. The porous structure can provide a large surface area for the attachment and fusion of bone tissue, thereby enhancing the bone integration ability and long-term biological stability of the implant prosthesis. Moreover, the connected pores can transmit biological factors, nutrients, and promote bone ingrowth. Therefore, more in-depth research has been carried out in the field of bone scaffold engineering.

[0003] As a minimal surface that shows periodic changes in three directions, the Triply Periodic Minimal Surface (TPMS) has the advantages of high connectivity, easy control of geometric parameters, large surface area, and suitability for cell adhesion and growth. Currently, there have been studies analyzing the pore characteristics, mechanical properties, fatigue life, and other properties of TPMS porous scaffolds. However, there is a lack of a systematic and complete solution for the screening method of porous implants in clinical research. Therefore, how to efficiently and quickly select 3D printed metal porous scaffolds suitable for specific implantation sites has become an urgent problem for those skilled in the art to solve. Summary of the Invention

[0004] In order to solve the problems existing in the background art, the present invention provides a screening method for 3D printed titanium alloy porous scaffolds to quickly and effectively select porous implants suitable for the implantation site, including:

[0005] S1: According to the Diamond structure and the Gyroid structure, titanium alloy powder is made into multiple 3D titanium alloy porous scaffolds with different relative densities and different unit sizes through a metal 3D printer;

[0006] S2: The multiple 3D titanium alloy porous scaffolds are successively subjected to ultrasonic cleaning and sandblasting to obtain multiple first 3D titanium alloy porous scaffolds;

[0007] S3: Place the first 3D titanium alloy porous scaffold under a microscope to observe and judge the structural integrity of the first 3D titanium alloy porous scaffold at different relative densities. For the first 3D titanium alloy porous scaffolds with incomplete structures, all the first 3D titanium alloy porous scaffolds with the same relative density are removed to obtain multiple second 3D titanium alloy porous scaffolds;

[0008] S4: Use micro-computed tomography and scanning electron microscopy to scan multiple second 3D titanium alloy porous scaffolds respectively to generate two-dimensional slice image data; and calculate the porosity and pore size of the second 3D titanium alloy porous scaffolds according to the two-dimensional slice image data; remove all the second 3D titanium alloy porous scaffolds with the same unit size that do not meet the preset porosity and pore size; and perform morphological characterization on the remaining second 3D titanium alloy porous scaffolds to judge whether there is powder blockage. For the second 3D titanium alloy porous scaffolds with powder blockage, all the second 3D titanium alloy porous scaffolds with the same unit size are removed to obtain multiple third 3D titanium alloy porous scaffolds;

[0009] S5: Use static compression to calculate the mechanical properties of the third 3D titanium alloy porous scaffolds respectively, and screen out multiple fourth 3D printed titanium alloy porous scaffolds whose mechanical properties meet the preset conditions and match the elastic modulus of the implantation site;

[0010] S6: Conduct fatigue tests on multiple fourth 3D printed titanium alloy porous scaffolds, and screen out 3D printed titanium alloy porous scaffolds that meet the preset fatigue degree.

[0011] Furthermore, the relative density of the 3D titanium alloy porous scaffold is 10% - 30%, and the unit size is 1 mm - 2 mm; wherein, the relative density is defined as the ratio of the density of the porous scaffold to that of titanium alloy, and the unit size refers to the side length of a single cell of the porous scaffold.

[0012] Furthermore, the printing design formula for the Diamond structure is:

[0013]

[0014] wherein, represents the printing design formula for the Diamond structure, t represents the relative density of the porous scaffold; x, y, z represent three-dimensional coordinates;

[0015] The printing design formula for the Gyroid structure is:

[0016]

[0017] wherein, represents the printing design formula for the Gyroid structure; t is to control the relative density of the porous scaffold.

[0018] Furthermore, the 3D printed titanium alloy porous scaffold is manufactured by an EBM printer produced by Arcam. Ti-6Al-4V medical grade powder with a particle size range of 65μm - 105μm is used as the raw material for EBM printing, and the 3D printed titanium alloy porous scaffold is formed by melting the powder layer by layer.

[0019] Furthermore, during the ultrasonic cleaning process, the frequency of the cleaning machine is stabilized at about 40KHz, the cleaning time is about 15 minutes, the sandblasting pressure is about 0.55MPa, and the particle size of the glass beads used for sandblasting is 63μm.

[0020] Furthermore, calculating the porosity and pore size of the second 3D titanium alloy porous scaffold includes: using Mimics 20.0 software to perform 3D reconstruction of the second 3D titanium alloy porous scaffold based on two-dimensional slice image data, and then importing the reconstructed 3D model into 3-matic 11.0 software to calculate the actual porosity and pore size of the second 3D titanium alloy porous scaffold.

[0021] Furthermore, calculating the mechanical properties of the third 3D titanium alloy porous scaffold includes:

[0022] Performing a static compression experiment on the third 3D titanium alloy porous scaffold according to the metal material compression test standard of GB / T 7314-2017. Three sets of repeated experiments are conducted on scaffolds of the same structure. The experiment is completed by an ETM series electronic universal testing machine. The average rate of the compression process is 1mm / min. The experiment ends when the sample reaches 60% strain. The average compression performance during the experiment is calculated from the real-time force and displacement data, and then the load-displacement data is converted into stress-strain data, and the mechanical properties of the scaffold are obtained from the stress-strain data.

[0023] Furthermore, performing a fatigue test on multiple fourth 3D printed titanium alloy porous scaffolds includes:

[0024] The fatigue experiment is carried out on an INSTRON fatigue testing machine, model E10BMTB. The loading frequency f is 10Hz, and the loading waveform belongs to a sine wave. The ratio of the minimum loading stress to the maximum loading stress is called the stress ratio R, where R = 0.1. The fatigue life is defined as the number of stress loadings when the fourth 3D printed titanium alloy porous scaffold fractures under the same loading stress.

[0025] The present invention has at least the following beneficial effects

[0026] The present invention provides a screening method for 3D printed titanium alloy porous scaffolds. According to the actual implantation site of the patient, it can quickly and effectively screen out 3D printed titanium alloy porous scaffolds with good pore connectivity, complete structure, high mechanical strength, mechanical stability and high fatigue life, meeting conditions such as the transmission of biological factors, nutrients and promoting bone ingrowth, thereby enhancing the prosthesis-bone integration ability and long-term biological stability. In addition, the proposed Gibson-Ashby equation can provide mechanical property prediction for the design of 3D printed titanium alloy porous scaffolds, effectively avoiding the residue of unmelted powder and impurity components on the surface of 3D printed titanium alloy porous scaffolds. Moreover, the method of the present invention is also applicable to the screening of porous scaffolds of other materials such as cobalt-chromium-molybdenum and peek, with a wide application range and strong practicability. Brief Description of the Drawings

[0027] Figure 1 is the flowchart of the method of the present invention;

[0028] Figure 2 is the design model and physical model diagram of the 3D printed titanium alloy porous scaffold in the present invention;

[0029] Figure 3 is the SEM diagram of the 3D printed titanium alloy porous scaffold before and after sandblasting in the present invention;

[0030] Figure 4 is the mechanical property test diagram of the 3D printed titanium alloy porous scaffold in the present invention;

[0031] Figure 5 is the fatigue test diagram of the 3D printed titanium alloy porous scaffold in the present invention. Detailed Embodiments

[0032] The following specific examples illustrate the embodiments of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the drawings provided in the following examples only illustrate the basic concept of the present invention schematically. Without conflict, the following examples and the features in the examples can be combined with each other.

[0033] Among them, the drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and should not be construed as a limitation to the present invention; in order to better illustrate the embodiments of the present invention, some components in the drawings will be omitted, enlarged or reduced, which do not represent the dimensions of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0034] In the drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes and cannot be construed as a limitation of the present invention. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0035] Please refer to Figure 1 , the present invention provides a screening method for 3D printed titanium alloy porous scaffolds, including:

[0036] S1: According to the Diamond structure and the Gyroid structure, titanium alloy powder is made into a plurality of 3D titanium alloy porous scaffolds with different relative densities and different unit sizes through a metal 3D printer;

[0037] Preferably, the printing design formula for the Diamond structure is:

[0038]

[0039] Among them, represents the printing design formula of the Diamond structure, t represents the relative density of the porous scaffold; x, y, z represent three-dimensional coordinates;

[0040] The printing design formula for the Gyroid structure is:

[0041]

[0042] Among them, represents the printing design formula of the Gyroid structure; t is used to control the relative density of the porous scaffold.

[0043] In an embodiment, in the embodiments of the present invention, the t values of the Diamond structure and the Gyroid structure are respectively taken as 1, 0.88, 0.76, 0.63, 0.49 and 1.22, 1.08, 0.92, 0.7, 0.61, corresponding to the relative densities of 10%, 15%, 20%, 25%, 30% of the porous scaffold.

[0044] Preferably, the 3D printed titanium alloy porous scaffold is manufactured by an EBM printer produced by Arcam. The Ti-6Al-4V medical grade powder with a particle size range of 65μm to 105μm is used as the raw material for EBM printing. The 3D printed titanium alloy porous scaffold is formed by melting the powder layer by layer. The design model and physical model of the 3D printed titanium alloy scaffold are as Figure 2 shown. The height of the scaffold is 20mm and the bottom diameter is 10mm.

[0045] S2: Ultrasonically clean and sandblast multiple 3D titanium alloy porous scaffolds in sequence to obtain multiple first 3D titanium alloy porous scaffolds;

[0046] Preferably, the 3D titanium alloy porous scaffold is ultrasonically cleaned to remove contaminants and dust on the surface of the porous scaffold, and then sandblasted to remove residual powder inside the porous scaffold. During the ultrasonic cleaning process, the frequency of the cleaning machine is stabilized at about 40KHz, the cleaning time is about 15min, the sandblasting pressure is about 0.55MPa, the particle size of the glass beads used for sandblasting is 63μm, and there is no sand residue on the sandblasted porous scaffold, which is harmless to the human body and meets the basic biological performance requirements of implants.

[0047] In the embodiment of the present invention, 3D printed titanium alloy porous scaffolds with 30 structures are prepared. The unit sizes are 1mm, 1.5mm, and 2mm respectively, and the relative densities are 10%, 15%, 20%, 25%, and 30% respectively, totaling 90. For easy distinction, the scaffolds are numbered DX-Y and GX-Y, where D and G represent Diamond and Gyroid units respectively, X is the relative density, and Y is the unit size.

[0048] S3: Place the first 3D titanium alloy porous scaffolds under a microscope to observe and judge the structural integrity of the first 3D titanium alloy porous scaffolds under different relative densities. For the first 3D titanium alloy porous scaffolds with incomplete structures, all the first 3D titanium alloy porous scaffolds with the same relative density are removed to obtain multiple second 3D titanium alloy porous scaffolds;

[0049] Use an ordinary optical microscope to observe the structural integrity of the 3D titanium alloy porous scaffold. Due to the excessive porosity and too small relative density, the rod diameter of the 3D titanium alloy porous scaffold will be too small, resulting in discontinuous rod diameter fractures. For example, through microscopic observation, it is found that there are partial rod diameter fractures in some of the first 3D titanium alloy porous scaffolds with a relative density of 10%. Then, all the first 3D titanium alloy porous scaffolds with a relative density of 10% are removed, and the remaining first 3D titanium alloy porous scaffolds are all first 3D titanium alloy porous scaffolds with high structural integrity.

[0050] S4: Use micro-computed tomography and scanning electron microscopy to scan multiple second 3D titanium alloy porous scaffolds respectively to generate two-dimensional slice image data; and calculate the porosity and pore size of the second 3D titanium alloy porous scaffolds according to the two-dimensional slice image data; reject all the second 3D titanium alloy porous scaffolds with the same unit size that do not meet the preset porosity and pore size; and perform morphological characterization on the remaining second 3D titanium alloy porous scaffolds to determine whether there is powder blockage. For the second 3D titanium alloy porous scaffolds with powder blockage, reject all the second 3D titanium alloy porous scaffolds with the same unit size to obtain multiple third 3D titanium alloy porous scaffolds;

[0051] Example: In this invention, a Micro-CT scanner Diondo d2, Germany was used to scan scaffolds D15-1.5, D15-2, G15-1.5 and G15-2. Under the conditions of a scanning voltage of 210 kV and a scanning current of 110 μA, the samples were scanned with a resolution of 7 μm to generate two-dimensional slice image data. The Mimics 20.0 software was used to perform three-dimensional reconstruction on the two-dimensional CT data of the scaffolds, and then the reconstructed three-dimensional model was imported into the 3-matic 11.0 software to calculate the actual porosity and pore size of the scaffolds, as shown in Table 1. Finally, SEM morphological characterization was performed on the 3D printed titanium alloy porous scaffolds before and after sandblasting, as Figure 3 shown.

[0052] Table 1 Actual pore parameters of 3D printed titanium alloy porous scaffolds

[0053]

[0054] It can be seen from the results of Micro-CT and SEM that all scaffolds meet the pore size requirements of porous implants (greater than 300 μm, i.e., the preset pore size and porosity). However, there is powder blockage in the porous scaffolds with a unit size of 1 mm. Therefore, the 3D printed titanium alloy porous scaffolds with a unit size of 1 mm were screened out. And sandblasting treatment can effectively remove the bonded powder on the surface of the scaffolds and provide a stable and reliable scaffold structure. In summary, the porous scaffolds with a unit size greater than or equal to 1.5 mm are suitable for the EBM manufacturing process, have an acceptable pore size and good pore connectivity, and can make great contributions in aspects such as transmitting biological factors and nutrients and promoting bone ingrowth.

[0055] S5: Use static compression to calculate the mechanical properties of the third 3D titanium alloy porous scaffolds respectively, and screen out multiple fourth 3D printed titanium alloy porous scaffolds whose mechanical properties meet the preset conditions and match the elastic modulus of the implantation site;

[0056] Preferably, the calculation of the mechanical properties of the third 3D titanium alloy porous scaffolds includes:

[0057] The static compression experiment was carried out on the third 3D titanium alloy porous scaffold according to the metal material compression test standard of GB / T 7314-2017. Three repeated experiments were conducted on scaffolds of the same structure. The experiment was completed by an ETM series electronic universal testing machine. The average rate during the compression process was 1 mm / min, and the experiment ended when the sample reached 60% strain. The average compression performance during the experiment was calculated from the real-time force and displacement data, and then the load-displacement data was converted into stress-strain data, and the mechanical properties of the scaffold were obtained from the stress-strain data.

[0058] Example: According to the pore characterization results, the present invention carried out a static compression experiment on 3D printed titanium alloy porous scaffolds with unit sizes of 1.5 mm and 2 mm according to the metal material compression test standard of GB / T 7314-2017. Three repeated experiments were conducted on scaffolds of the same structure. The experiment was completed by an ETM series electronic universal testing machine developed by Shenzhen Wance Equipment Co., Ltd. The average rate during the compression process was 1 mm / min, and the experiment ended when the sample reached 60% strain. The average compression performance during the experiment was calculated from the real-time force and displacement data, and then the load-displacement data was converted into stress-strain data, and the mechanical properties of the scaffold were as Figure 4 shown.

[0059] Since the error bar height of the G scaffold is less than that of the D scaffold, it is speculated that the mechanical stability of the G structure is better than that of the D structure. Therefore, the D scaffold was screened out. In addition, the elastic moduli of human cortical bone and cancellous bone are 3 GPa - 27.6 GPa and 0.1 GPa - 1.1 GPa respectively. The mechanical properties of the G15, G20, G25, and G30 scaffolds are all within the applicable range of human bones. However, the G15 scaffold has a higher porosity and pore size, showing stronger potential in terms of biological factor, nutrient transport, and bone ingrowth. Therefore, the G15-1.5 scaffold and the G15-2 scaffold were selected for fatigue testing.

[0060] S6: Conduct fatigue testing on multiple fourth 3D printed titanium alloy porous scaffolds, and screen out 3D printed titanium alloy porous scaffolds that meet the preset fatigue degree;

[0061] Preferably, the fatigue testing of multiple fourth 3D printed titanium alloy porous scaffolds includes:

[0062] The fatigue experiment was carried out on an INSTRON fatigue testing machine, model E10BMTB. The loading frequency f was 10 Hz, and the loading waveform was a sine wave. The ratio of the minimum loading stress to the maximum loading stress is called the stress ratio R, where R = 0.1; the fatigue degree is defined as the number of stress loadings when the fourth 3D printed titanium alloy porous scaffold fractures under the same loading stress.

[0063] Please refer to Figure 5 , based on the compression test results, the G15-1.5 scaffold and G15-2 scaffold with good mechanical stability and pore connectivity were selected for compression-compression fatigue tests. The fatigue experiments were carried out on an INSTRON fatigue testing machine in the United States, model E10BMTB. The loading frequency f was 10 Hz, and the loading waveform was a sine wave. The ratio of the minimum loading stress to the maximum loading stress was called the stress ratio R, where R = 0.1. It can be seen from the fatigue tests that fatigue ratcheting and fatigue damage are the main causes of fatigue failure of 3D printed titanium alloy porous scaffolds, starting from the rough surface of the scaffolds and caused by the accumulation of microplastic deformation. Fatigue ratcheting occurs first during the cyclic compression of the porous scaffolds and further induces fatigue damage, where fatigue ratcheting plays a dominant role in the fatigue failure of the scaffolds. The analysis results of the fatigue failure mechanism show that the fatigue behavior of the porous scaffolds with large unit sizes exhibits slow strain accumulation. Without reducing the porosity of the scaffolds, larger-sized scaffolds help reduce the number of notches for crack initiation, thereby improving the fatigue life of the scaffolds. Specifically, the G15-2 scaffold has a stronger crack propagation resistance ability than the G15-1.5 scaffold.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the present technical solution, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A screening method for 3D printed titanium alloy porous scaffolds, characterized in that, Including: S1: Fabricate multiple 3D titanium alloy porous scaffolds with different relative densities and different unit sizes from titanium alloy powder through a metal 3D printer according to the Diamond structure and the Gyroid structure; S2: Ultrasonically clean and sandblast multiple 3D titanium alloy porous scaffolds in sequence to obtain multiple first 3D titanium alloy porous scaffolds; S3: Place the first 3D titanium alloy porous scaffolds under a microscope to observe and judge the structural integrity of the first 3D titanium alloy porous scaffolds under different relative densities. Reject all the first 3D titanium alloy porous scaffolds with incomplete structures under the same relative density to obtain multiple second 3D titanium alloy porous scaffolds; S4: Use micro-computed tomography and scanning electron microscopy to scan multiple second 3D titanium alloy porous scaffolds respectively to generate two-dimensional slice image data; and calculate the porosity and pore size of the second 3D titanium alloy porous scaffolds according to the two-dimensional slice image data. Reject all the second 3D titanium alloy porous scaffolds that do not meet the preset porosity and pore size under the same unit size; and conduct morphological characterization on the remaining second 3D titanium alloy porous scaffolds to judge whether there is powder blockage. Reject all the second 3D titanium alloy porous scaffolds with powder blockage under the same unit size to obtain multiple third 3D titanium alloy porous scaffolds; S5: Use static compression to calculate the mechanical properties of the third 3D titanium alloy porous scaffolds respectively, and screen out multiple fourth 3D printed titanium alloy porous scaffolds whose mechanical properties meet the preset conditions and match the elastic modulus of the implantation site; S6: Conduct fatigue tests on multiple fourth 3D printed titanium alloy porous scaffolds, and screen out 3D printed titanium alloy porous scaffolds that meet the preset fatigue degree.

2. The screening method of a 3D printed titanium alloy porous scaffold according to claim 1, characterized in that The relative density of the 3D titanium alloy porous scaffold is 10% - 30%, and the unit size is 1 mm - 2 mm; wherein, the relative density is defined as the ratio of the density of the porous scaffold to that of the titanium alloy, and the unit size refers to the side length of a single cell of the porous scaffold.

3. The screening method of a 3D printed titanium alloy porous scaffold according to claim 1, characterized in that, The printing design formula of the Diamond structure is: Among them, represents the printing design formula of the Diamond structure, t represents the relative density of the porous scaffold; x, y, and z represent three-dimensional coordinates; The printing design formula of the Gyroid structure is: Among them, represents the printing design formula of the Gyroid structure; t controls the relative density of the porous scaffold.

4. The screening method of a 3D printed titanium alloy porous scaffold according to claim 1, characterized in that The 3D printed titanium alloy porous scaffold is manufactured by an EBM printer produced by Arcam Company, and Ti-6Al-4V medical grade powder with a particle size range of 65 μm - 105 μm is used as the EBM printing raw material, and the 3D printed titanium alloy porous scaffold is formed by melting the powder layer by layer.

5. The screening method of a 3D printed titanium alloy porous scaffold according to claim 1, characterized in that, During the ultrasonic cleaning process, the frequency of the cleaning machine is stabilized at about 40 KHz, the cleaning time is about 15 min, the sandblasting pressure is about 0.55 MPa, and the particle size of the glass beads used for sandblasting is 63 μm.

6. The screening method of a 3D printed titanium alloy porous scaffold according to claim 1, wherein The calculating the porosity and pore size of the second 3D titanium alloy porous scaffold includes: using Mimics 20.0 software to conduct three-dimensional reconstruction on the second 3D titanium alloy porous scaffold according to the two-dimensional slice image data, and then importing the reconstructed three-dimensional model into 3-matic 11.0 software to calculate the actual porosity and pore size of the second 3D titanium alloy porous scaffold.

7. A screening method for a 3D printed titanium alloy porous scaffold according to claim 1, characterized in that, The calculation of the mechanical properties of the third 3D titanium alloy porous scaffold includes: Conduct static compression experiments on the third 3D titanium alloy porous scaffold according to the metal material compression test standard of GB / T 7314-2017. Three sets of repeated experiments are carried out on scaffolds of the same structure. The experiment is completed by an ETM series electronic universal testing machine. The average rate of the compression process is 1 mm / min. The experiment ends when the sample reaches 60% strain. The average compression performance during the experiment is calculated from the real-time force and displacement data, and then the load-displacement data is converted into stress-strain data, and the mechanical properties of the scaffold are obtained from the stress-strain data.

8. The screening method of a 3D printed titanium alloy porous scaffold according to claim 1, characterized in that, The fatigue test on multiple fourth 3D printed titanium alloy porous scaffolds includes: The fatigue experiment is carried out on an INSTRON fatigue testing machine, model E10BMTB. The loading frequency f is 10 Hz, and the loading waveform belongs to a sine wave. The ratio of the minimum loading stress to the maximum loading stress is called the stress ratio R, where R = 0.1; the fatigue life is defined as the number of stress loadings when the fourth 3D printed titanium alloy porous scaffold fractures under the same loading stress.

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