Method for preparing porous titanium alloy dental implant through binder jet 3D printing

Abstract

The invention provides a method for preparing a porous titanium alloy dental implant through binder jet 3D printing, and relates to the field of biomedical materials. Comprising the following steps that spherical TC4 titanium alloy powder with different particle sizes is mixed in a powder mixing machine, and the mixed powder is dried; modeling software is used for designing a proper porous printing model, a file is exported into a printer program, and a 3D printer is used for printing; the printed green body and the workbench are dried and cured together, the dried and cured green body is taken out, and redundant powder on the surface of the material and in the porous section is removed; and putting the green body into a sintering furnace for degreasing and sintering, cooling to a certain temperature, reheating for annealing treatment, and finally cooling to room temperature along with the furnace to obtain the porous titanium alloy implant. The density is improved through mutual cooperation of powder with different particle sizes, the pore size and porosity are adjusted by changing a model, the sintering process and annealing treatment are combined, and the obtained product meets the performance requirements of medical dental implants.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical biological implant materials, and in particular relates to a porous titanium alloy dental implant suitable for dentistry, and more specifically to a method for preparing a porous titanium alloy dental implant by adhesive jet 3D printing. Background Art

[0002] Many people lose one or more teeth due to many reasons such as caries, periodontal disease, trauma, etc. According to the Global Dental Health Report, tooth loss is a common problem that affects a considerable portion of the adult population. In response to a series of problems with traditional restoration methods, such as unstable dentures, damage to adjacent teeth, and discomfort caused by long-term wear, implant restoration technology has developed rapidly. Porous material implants can obtain an elastic modulus that matches human bones by adjusting the pore size and porosity, and can maintain good yield strength and fatigue strength. Porous metal implants also have good biocompatibility, which can not only provide more metal surfaces to promote cell attachment, growth, proliferation and differentiation, but also use interconnected pores to promote the transport of nutrients and metabolic waste.

[0003] Binder jetting 3D printing is an additive manufacturing technology that uses a binder to bond powder materials layer by layer to form a three-dimensional object. Each layer of powder is fixed together by the spraying of a binder, and then undergoes post-processing, such as degreasing or sintering, to enhance the structural strength and stability. During the post-processing of binder jetting 3D printing technology, it is difficult to ensure uniform temperature during the heating process, and the mechanical properties of the material in different directions are uneven due to the temperature gradient. In binder jetting 3D printing production, the cooling stage of sintering is often accompanied by material shrinkage, which causes certain internal stresses in the material. The existing production process directly cools to room temperature after sintering, and then performs heat treatment or other operations to eliminate the internal stresses generated during the heating and cooling processes. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing a porous titanium alloy dental implant by binder jet 3D printing, so as to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] A method for preparing a porous titanium alloy dental implant by binder jet 3D printing, comprising the following steps:

[0007] (1) mixing spherical TC4 titanium alloy powders of different particle sizes in a powder mixer and drying the mixed powders;

[0008] (2) Use modeling software to design a suitable porous printing model, export the file to the printer program, and print it using a 3D printer;

[0009] (3) drying and curing the printed green body together with the workbench, taking out the dried and cured green body and cleaning the excess powder on the material surface and inside the porous section;

[0010] (4) The green body is placed in a sintering furnace for degreasing and sintering, cooled to a certain temperature and then reheated for annealing, and finally cooled to room temperature in the furnace to obtain a porous titanium alloy implant.

[0011] The technical solution is further optimized, and the spherical TC4 titanium alloy powder includes spherical titanium alloy powder A and spherical titanium alloy powder B, and the diameters of the spherical titanium alloy powder A and the spherical titanium alloy powder B are 0-15 μm and 15-53 μm, respectively.

[0012] The technical solution is further optimized, the mixing ratio of the spherical titanium alloy powder A and the spherical titanium alloy powder B is 1:4-1:6, the mixing time is 2 hours, and the drying temperature of the mixed titanium alloy powder is 140°C for 2-3 hours.

[0013] The technical solution is further optimized, the porous printing model can be divided into an upper platform, a porous section and a thread, the upper platform and the porous section are connected by a frustum, and the thread is arranged on the outer surface of the porous section.

[0014] The technical solution is further optimized. In step (2), the mixed and dried titanium alloy powder is added into the hopper of the 3D printer for printing. The printing parameters are as follows: the binder saturation is 20%-40%, the layer thickness is 70-150 μm, the powder bed temperature is 30°C-60°C, and the drying time is 10-15s.

[0015] The technical solution is further optimized, and the drying and curing temperature in step (3) is 130-150° C. and the time is 3 hours.

[0016] The technical solution is further optimized, and the degreasing temperature in step (4) is 600-700°C and the insulation time is 2h.

[0017] The technical solution is further optimized, and the sintering temperature in step (4) is 1150-1300° C., and the holding time is 2-3 hours.

[0018] The technical solution is further optimized, in step (4), the green body after sintering is cooled to 100°C and then heated for annealing, the annealing temperature is 500-600°C, and after keeping the temperature for 2 hours, it is cooled to room temperature in the furnace.

[0019] The technical solution is further optimized by introducing inert gas for protection during the entire process in the sintering furnace.

[0020] Different from the prior art, the above technical solution has the following beneficial effects:

[0021] The present invention provides a method for preparing a porous titanium alloy dental implant by binder jet 3D printing, wherein titanium alloy powders of different particle sizes are combined with each other and the voids of coarse powder are filled with fine powder, so that the density of the titanium alloy is increased within a certain range, thereby ensuring that the titanium alloy can still have the performance that meets the requirements for the use of dental implants after having a certain number of pores.

[0022] The present invention combines the sintering process of binder jet 3D printing with post-heat treatment, and directly performs annealing after the sintering temperature drops to a certain temperature, making the production steps of the titanium alloy more coherent and effectively avoiding oxidation of the titanium alloy during repeated heating. Through the operation of sintering + annealing heat treatment, the performance of the titanium alloy implant is enhanced, ensuring its various performances during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the porous titanium alloy implant model structure;

[0024] Among them, 1 is the upper platform, 2 is the porous section, and 3 is the thread.

[0025] Figure 2 Schematic diagram of sintering temperature curve. DETAILED DESCRIPTION

[0026] In order to explain the technical content, structural features, achieved objectives and effects of the technical solution in detail, the following is a detailed description in conjunction with specific embodiments and accompanying drawings.

[0027] [Example 1]

[0028] A method for preparing a porous titanium alloy dental implant by binder jet 3D printing, characterized in that it comprises the following steps:

[0029] (1) Spherical TC4 titanium alloy powders A and B were mixed in a powder mixer at a ratio of 1:4 for 2 h, and the mixed powders were dried at 140° C. for 2 h;

[0030] (2) Use modeling software to design Figure 1 The porous printing model of suitable size is shown, and the file is exported to the printer program. The mixed TC4 titanium alloy powder is added to the hopper of the 3D printer for printing. The printing parameters are as follows: the binder saturation is 20%, the layer thickness is 70μm, the powder bed temperature is 45℃, and the drying time is 10s.

[0031] (3) The printed green body and the workbench are placed in a hot air blower for drying and curing; the drying and curing temperature is 130°C and the time is 3 hours. Then, a brush is used to clean the surface of the green body, and a blower is used to clean the excess powder inside the porous section of the green body.

[0032] (4) Take out the cleaned green body and put it into the sintering furnace for degreasing, sintering and annealing. Introduce argon gas into the sintering furnace for protection. The temperature setting is as shown in Figure 2 The specific temperature changes are as follows: first, the temperature is increased from room temperature to 600°C at a rate of 5°C / min for debinding, and the holding time is 2h; then the temperature is increased to 1150°C at a rate of 5°C / min for sintering, and the holding time is 2h, then the temperature is decreased to 100°C at a rate of 10°C / min, and then the temperature is increased to 500°C at a rate of 5°C / min for annealing, and the holding time is 2h, and finally the furnace is cooled to room temperature.

[0033] [Example 2]

[0034] A method for preparing a porous titanium alloy dental implant by binder jet 3D printing, characterized in that it comprises the following steps:

[0035] (1) Spherical TC4 titanium alloy powders A and B were mixed in a powder mixer at a ratio of 1:5 for 2 h, and the mixed powders were dried at 140° C. for 2.5 h;

[0036] (2) Use modeling software to design Figure 1 The porous printing model of suitable size is shown, and the file is exported to the printer program. The mixed TC4 titanium alloy powder is added to the hopper of the 3D printer for printing. The printing parameters are as follows: the binder saturation is 30%, the layer thickness is 100μm, the powder bed temperature is 45℃, and the drying time is 12s.

[0037] (3) The printed green body and the workbench are placed in a hot air blower for drying and curing; the drying and curing temperature is 140°C and the time is 3 hours. Then, a brush is used to clean the surface of the green body, and a blower is used to clean the excess powder inside the porous section of the green body.

[0038] (4) Take out the cleaned green body and put it into the sintering furnace for degreasing, sintering and annealing. Introduce argon gas into the sintering furnace for protection. The temperature setting is as shown in Figure 2The specific temperature changes are as follows: first, the temperature is increased from room temperature to 650°C at a rate of 5°C / min for debinding, and the holding time is 2h; then the temperature is increased to 1200°C at a rate of 5°C / min for sintering, and the holding time is 2.5h, then the temperature is decreased to 100°C at a rate of 10°C / min, and then the temperature is increased to 550°C at a rate of 5°C / min for annealing, and the holding time is 2h, and finally the furnace is cooled to room temperature.

[0039] [Example 3]

[0040] (1) Spherical TC4 titanium alloy powders A and B were mixed in a powder mixer at a ratio of 1:6 for 2 h, and the mixed powders were dried at 140° C. for 3 h;

[0041] (2) Use modeling software to design Figure 1 The porous printing model of suitable size is shown, and the file is exported to the printer program. The mixed TC4 titanium alloy powder is added to the hopper of the 3D printer for printing. The printing parameters are as follows: the binder saturation is 40%, the layer thickness is 150μm, the powder bed temperature is 45℃, and the drying time is 12s.

[0042] (3) The printed green body and the workbench are placed in a hot air blower for drying and curing; the drying and curing temperature is 140°C and the time is 3 hours. Then, a brush is used to clean the surface of the green body, and a blower is used to clean the excess powder inside the porous section of the green body.

[0043] (4) Take out the cleaned green body and put it into the sintering furnace for degreasing, sintering and annealing. Introduce argon gas into the sintering furnace for protection. The temperature setting is as shown in Figure 2 The specific temperature changes are as follows: first, the temperature is increased from room temperature to 700°C at a rate of 5°C / min for debinding, and the holding time is 2h; then the temperature is increased to 1250°C at a rate of 5°C / min for sintering, and the holding time is 3h, then the temperature is decreased to 100°C at a rate of 10°C / min, and then the temperature is increased to 600°C at a rate of 5°C / min for annealing, and the holding time is 2h, and finally the furnace is cooled to room temperature.

[0044] [Density calculation]

[0045] The density of each embodiment was measured by the Archimedean drainage method. The test pieces were placed in an ultrasonic cleaning machine and cleaned in alcohol for 30 minutes. The cleaned test pieces were taken out and dried with a hair dryer. Then, their weight m1 in air was weighed with an electronic balance, and their weight m2 in distilled water was weighed. The actual density ρ1 of the sample was calculated. Finally, the actual density was compared with the theoretical density ρ0 (4.43 g / cm 3 ) is divided by the density ρ2 of the sample. The density calculation formula is:

[0046]

[0047] The calculated densities of the embodiments are:

[0048] Example 1 Example 2 Example 3 Density 97.8％ 98.4％ 97.5％

[0049] The above embodiments are only used to illustrate rather than limit the technical solutions of the present invention. Although the present invention is described in detail with reference to the above embodiments, those skilled in the art should understand that the present invention can still be modified or replaced by equivalents. However, without departing from the scope of protection of the present invention and the claims, all specific extensions should be included in the protection scope of the present invention.

[0050] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "include..." or "comprise..." do not exclude the existence of other elements in the process, method, article or terminal device including the elements. In addition, in this article, "greater than", "less than", "exceed" and the like are understood to exclude the number itself; "above", "below", "within" and the like are understood to include the number itself.

[0051] Although the above embodiments have been described, once those skilled in the art know the basic creative concepts, they can make additional changes and modifications to these embodiments. Therefore, the above description is only an embodiment of the present invention and does not limit the patent protection scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for preparing a porous titanium alloy dental implant by binder jet 3D printing, characterized in that: The following steps are involved: (1) mixing spherical TC4 titanium alloy powders of different particle sizes in a powder mixer and drying the mixed powders; (2) Use modeling software to design a suitable porous printing model, export the file to the printer program, and print it using a 3D printer; (3) drying and curing the printed green body together with the workbench, taking out the dried and cured green body and cleaning the excess powder on the material surface and inside the porous section; (4) The green body is placed in a sintering furnace for degreasing and sintering, cooled to a certain temperature and then reheated for annealing, and finally cooled to room temperature in the furnace to obtain a porous titanium alloy implant.

2. The method for preparing a porous titanium alloy dental implant by binder jet 3D printing according to claim 1, characterized in that: The spherical TC4 titanium alloy powder comprises spherical titanium alloy powder A and spherical titanium alloy powder B. The diameters of the spherical titanium alloy powder A and the spherical titanium alloy powder B are 0-15 μm and 15-53 μm respectively.

3. The method for preparing a porous titanium alloy dental implant by binder jet 3D printing according to claim 1, characterized in that: The mixing ratio of the spherical titanium alloy powder A and the spherical titanium alloy powder B is 1:4-1:6, the mixing time is 2 hours, and the drying temperature of the mixed titanium alloy powder is 140° C., and the drying time is 2-3 hours.

4. The method for preparing a porous titanium alloy dental implant by binder jet 3D printing according to claim 1, characterized in that: The porous printing model can be divided into an upper platform, a porous section and a thread. The upper platform and the porous section are connected by a truncated cone, and the thread is arranged on the outer surface of the porous section.

5. The method for preparing a porous titanium alloy dental implant by binder jet 3D printing according to claim 1, characterized in that: In the step (2), the mixed and dried titanium alloy powder is added into the hopper of a 3D printer for printing, and the printing parameters are as follows: a binder saturation of 20%-40%, a layer thickness of 70-150 μm, a powder bed temperature of 30° C.-60° C., and a drying time of 10-15 seconds.

6. The method for preparing a porous titanium alloy dental implant by binder jet 3D printing according to claim 1, characterized in that: The drying and curing temperature in step (3) is 130-150° C. and the time is 3 hours.

7. The method for preparing a porous titanium alloy dental implant by binder jet 3D printing according to claim 1, characterized in that: The degreasing temperature in step (4) is 600-700° C. and the insulation time is 2 hours.

8. The method for preparing a porous titanium alloy dental implant by binder jet 3D printing according to claim 1, characterized in that: The sintering temperature in step (4) is 1150-1300° C., and the holding time is 2-3 hours.

9. The method for preparing a porous titanium alloy dental implant by binder jet 3D printing according to claim 1, characterized in that: In the step (4), the green body after sintering is cooled to 100° C. and then heated for annealing. The annealing temperature is 500-600° C. After being kept at this temperature for 2 hours, the green body is cooled to room temperature in the furnace.

10. The method for preparing a porous titanium alloy dental implant by binder jet 3D printing according to claim 1, characterized in that: In the entire process of step (4) in the sintering furnace, an inert gas is introduced for protection.

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