Method for strengthening mechanical properties of 3D printed polyether ether ketone by heat treatment

Abstract

The application provides a heat treatment method for strengthening the mechanical properties of 3D printing polyether ether ketone, which comprises the following steps: embedding treatment: placing the 3D printing polyether ether ketone product into a hot pressing tank, adding embedding material into the hot pressing tank until the 3D printing polyether ether ketone product is embedded therein; hot pressing treatment: increasing the temperature in the hot pressing tank to 280-350 DEG C, while filling inert gas into the hot pressing tank until the pressure in the hot pressing tank is 0.5-3.0 MPa, maintaining the condition of the hot pressing tank for 20-180 min, and performing hot pressing treatment on the 3D printing polyether ether ketone product; annealing treatment: annealing the 3D printing polyether ether ketone product after the hot pressing treatment by furnace cooling to room temperature to obtain the strengthened 3D printing polyether ether ketone. The application realizes the common improvement of the elongation at break and tensile breaking strength of the 3D printing polyether ether ketone product.

Description

Technical Field

[0001] This application relates to the field of 3D printing polyetheretherketone (PEEK) technology, and in particular to a heat treatment method for enhancing the mechanical properties of 3D printed PEEK. Background Technology

[0002] 3D printing technology has been widely used in aviation, aerospace, automobiles, ships, medical consumables and other fields, and is gradually expanding to multiple fields such as automobiles, energy and power, rail transportation and electronics, becoming the source of technological breakthroughs for multiple industrial chains.

[0003] Polyetheretherketone (PEEK), as a high-performance engineering plastic, possesses excellent high-temperature resistance, chemical corrosion resistance, and good mechanical properties, demonstrating enormous application potential in numerous fields such as aerospace, biomedicine, and the automotive industry. With the continuous development of 3D printing technology, its application in PEEK material processing is becoming increasingly widespread, enabling the manufacture of complex shapes and personalized customized products.

[0004] However, the insufficient elongation at break and toughness of polyetheretherketone (PEEK) 3D-printed products are currently a significant problem. This limits its use in applications requiring high material flexibility and impact resistance. For example, certain components in the aerospace field need materials that are not easily broken under complex stress and have a certain degree of deformation capability; implants in the biomedical field also require materials with good toughness to adapt to the dynamic mechanical environment of human tissue. Existing 3D-printed PEEK products, due to process limitations, have many internal defects, such as pores and unfused areas, which affect the continuity and uniformity of the material, making it difficult to achieve ideal levels of elongation at break and toughness.

[0005] Therefore, it is of great significance to develop a processing technology and preparation method for enhancing the performance of polyetheretherketone (PEEK) 3D printed products. Summary of the Invention

[0006] This application provides a heat treatment method to enhance the mechanical properties of 3D printed polyetheretherketone (PEEK) to solve the problems mentioned in the background art.

[0007] This application provides a heat treatment method to enhance the mechanical properties of 3D printed polyetheretherketone (PEEK), the method comprising the following steps:

[0008] (1) Embedding treatment: Place the 3D printed polyether ether ketone product into an autoclave, add embedding material into the autoclave until the 3D printed polyether ether ketone product is embedded therein;

[0009] (2) Hot pressing treatment: Raise the temperature inside the autoclave to 280-350℃, and at the same time fill the autoclave with inert gas until the pressure inside the autoclave is 0.5-3.0MPa. Maintain the autoclave conditions for 20-180 minutes to perform hot pressing treatment on the 3D printed polyether ether ketone product.

[0010] (3) Annealing treatment: The 3D printed polyether ether ketone product after hot pressing is cooled to room temperature in the furnace and then annealed to obtain the reinforced 3D printed polyether ether ketone.

[0011] Optionally, the temperature in the hot pressing process is 280-340℃, and the pressure inside the autoclave is 0.5-2.5MPa.

[0012] Optionally, the temperature in the hot pressing process is 280-335℃, and the pressure inside the autoclave is 0.6-2.3MPa.

[0013] Optional, the embedding process specifically includes:

[0014] Spread a layer of embedding material at the bottom of the autoclave, place the 3D printed polyetheretherketone (PEEK) product into the autoclave, and continue to add embedding material to the autoclave until the 3D printed PEEK product is embedded within it.

[0015] Optionally, the distance between each component of the 3D printed polyetheretherketone product and the edge or bottom of the autoclave is greater than or equal to 5 mm.

[0016] Optionally, the embedding material may include one or more of sodium chloride, zirconium oxide, glass beads, and hydroxyapatite.

[0017] Optionally, the particle size of the embedding material is 2-4 mm.

[0018] Optionally, after the annealing process, the process may also include: sandblasting the annealed 3D printed polyetheretherketone (PEEK) product to remove surface deposits, followed by cleaning and sterilization to obtain reinforced 3D printed PEEK.

[0019] Optionally, the heating rate in the hot pressing step is 10-30℃ / h.

[0020] Optionally, the hot pressing process includes: First stage: heating from room temperature to 120-150℃ at a heating rate of 10-30℃ / h, while simultaneously filling the autoclave with inert gas until the pressure inside the autoclave is 0.5-3.0MPa; Second stage: heating from 120-150℃ to 200-300℃ at a heating rate of 10-20℃ / h; Third stage: heating from 200-300℃ to 280℃-350℃ at a heating rate of 5-10℃ / h, holding at the temperature and pressure for 20-180min, and performing hot pressing on the 3D printed polyetheretherketone product.

[0021] The heat treatment method for enhancing the mechanical properties of 3D-printed polyetheretherketone (PEEK) provided in this application improves the elongation at break and toughness of 3D-printed PEEK products, and has the following advantages compared to existing technologies:

[0022] (1) By completely covering the 3D-printed polyetheretherketone (PEEK) product with an embedding material and simultaneously filling the autoclave with inert gas, the combined effect of the embedding material and the inert atmosphere prevents oxidation and decarburization of the 3D-printed PEEK product during subsequent high-temperature and high-pressure heat treatment, maintaining the original state of the PEEK product and ensuring that its quality and performance are not affected by high temperature and high pressure. Simultaneously, the 3D-printed PEEK product is kept in an inert gas atmosphere at a temperature of 280-350℃ and a pressure of 0.5-3.0MPa for hot pressing treatment. Hot pressing treatment can effectively repair micro-defects generated during the 3D printing process, such as micro-cracks and unfused areas, eliminate residual stress inside the product, reduce the porosity of the parts and increase their hardness, making the microstructure of the product more uniform. At the same time, the molecules inside the PEEK product can self-reorganize, thereby improving the stability and density of the final product, and thus improving the elongation at break and tensile strength of the 3D-printed PEEK product, giving it better plasticity and toughness.

[0023] (2) Controlling the particle size of the embedding material helps stabilize the heat treatment effect. If the particle size of the embedding material is too large, it will leave pits on the surface of the 3D printed polyetheretherketone product. If the particle size of the embedding material is too small, the particles of the embedding material may enter the pores of the 3D printed polyetheretherketone product, affecting the mechanical properties of the 3D printed polyetheretherketone product.

[0024] (3) By strictly controlling the temperature in the hot pressing process, the temperature is raised from room temperature to 120-150℃ in the first stage at a rate of 10-30℃ / h, while inert gas is introduced into the autoclave until the pressure inside the autoclave is 0.5-3.0MPa. During this process, the heating rate has little effect on the internal molecular structure of the 3D printed polyether ether ketone product. The heating rate is fast and can reduce the hot pressing cycle. The second stage involves heating from 120-150℃ to 200-300℃ at a rate of 10-20℃ / h. During this process, the molecules within the 3D-printed polyetheretherketone (PEEK) product begin to self-reorganize, but at a relatively slow rate. The third stage involves heating from 200-300℃ to 280℃-350℃ at a rate of 5-10℃ / h. In this application, the heating rate is gradually slowed down and strictly controlled to avoid excessively rapid temperature changes that could lead to intense molecular interactions within the 3D-printed PEEK product, resulting in structural changes (such as shrinkage deformation). Strict temperature control during the heat treatment process can more stably eliminate internal stress in the 3D-printed PEEK product, thereby improving the stability and density of the final product, and consequently increasing the elongation at break and tensile strength of the 3D-printed PEEK product.

[0025] (4) The process flow of this application is reasonable, the processing is simple, and it is suitable for large-scale operation. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A process diagram of a heat treatment method for enhancing the mechanical properties of 3D printed polyetheretherketone (PEEK) according to an embodiment of this application;

[0028] Figure 2 (a) is a physical image of the 3D-printed polyetheretherketone (PEEK) product provided in Comparative Example 1. Figure 2 (b) is a physical image of the 3D printed polyetheretherketone product provided in Example 5. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of this application.

[0030] like Figure 1 As shown, this application provides a heat treatment method to enhance the mechanical properties of 3D printed polyetheretherketone (PEEK), the method comprising the following steps:

[0031] (1) Embedding treatment: Place the 3D printed polyether ether ketone product into an autoclave, add embedding material into the autoclave until the 3D printed polyether ether ketone product is embedded therein;

[0032] (2) Hot pressing treatment: Raise the temperature inside the autoclave to 280-350℃, and at the same time fill the autoclave with inert gas until the pressure inside the autoclave is 0.5-3.0MPa. Maintain the autoclave conditions for 20-180 minutes to perform hot pressing treatment on the 3D printed polyether ether ketone product.

[0033] (3) Annealing treatment: The 3D printed polyether ether ketone product after hot pressing is cooled to room temperature in the furnace and then annealed to obtain the reinforced 3D printed polyether ether ketone.

[0034] Specifically, by heat-treating 3D-printed polyetheretherketone (PEEEK) products, the internal stress of the 3D-printed parts is reduced and their mechanical properties are improved, thus addressing the problems of insufficient elongation at break and toughness in existing PEEK 3D-printed products. First, the 3D-printed PEEK product is placed in an autoclave, and embedding material is added to ensure the product is completely covered. During heat treatment, the 3D-printed PEEK product is exposed to a high-temperature environment. The embedding material isolates the product from air, preventing surface oxidation and maintaining its original state, ensuring its quality and performance are unaffected. Simultaneously, at high temperatures, the carbon on the surface of the 3D-printed PEEK product is easily oxidized, leading to decarburization. The embedding material effectively prevents this reaction, maintaining a stable carbon content and thus ensuring its hardness and strength. Covering the 3D-printed PEEK product with embedding material helps prevent oxidation and decarburization during heat treatment.

[0035] The temperature inside the autoclave is raised to 280°C to 350°C, which is higher than the crystallization temperature of polyetheretherketone (PEEK) but lower than its melting point. At the same time, inert gas is introduced into the autoclave until the pressure inside the autoclave is 0.5-3.0 MPa. In the inert gas environment, oxidation of the PEEK product is prevented under high temperature and high pressure, thus maintaining the surface color and structural dimensions of the 3D printed PEEK product without change, ensuring the original appearance and structure of the 3D printed PEEK product. Only the internal stress is optimized.

[0036] The inert gas used is argon or nitrogen.

[0037] The 3D-printed polyetheretherketone (PEEK) product is kept in an inert gas atmosphere at a temperature of 280-350℃ and a pressure of 0.5-3.0MPa for 20-180 minutes for hot pressing. This hot pressing process ensures that the heat is fully and evenly applied to every microstructure of the product, effectively repairing micro-defects generated during 3D printing, such as micro-cracks and unfused areas. It also eliminates residual stress within the product, reduces porosity, increases hardness, and makes the microstructure more uniform, reducing fragility and the risk of breakage. This improves the elongation at break and tensile strength of the 3D-printed PEEK product. Furthermore, for PEEK, heat treatment allows the internal molecules to self-reorganize, thereby improving the stability and density of the final product.

[0038] Finally, the hot-pressed 3D-printed polyetheretherketone (PEEK) product is cooled to room temperature in the furnace for annealing. Gradual cooling during this process avoids the formation of internal stress and warping, resulting in a strengthened 3D-printed PEEK product that combines elongation at break and toughness. The annealing time is 60-240 minutes.

[0039] This application achieves a combined improvement in the elongation at break and toughness of 3D-printed polyetheretherketone (PEEK) products through the aforementioned scheme. By completely covering the 3D-printed PEEK product with an embedding material and simultaneously filling the autoclave with inert gas, the combined effect of the embedding material and the inert atmosphere prevents oxidation and decarburization of the 3D-printed PEEK product during subsequent high-temperature and high-pressure heat treatment, maintaining the original state of the PEEK product and ensuring that its quality and performance are not affected by high temperature and high pressure. Simultaneously, the 3D-printed polyetheretherketone (PEEK) products are kept in an inert gas atmosphere at a temperature of 280-350℃ and a pressure of 0.5-3.0MPa for hot pressing treatment. Hot pressing treatment can effectively repair micro-defects generated during the 3D printing process, such as micro-cracks and unfused areas, eliminate residual stress inside the product, reduce the porosity of the parts and increase their hardness, making the microstructure of the product more uniform. At the same time, the internal molecules of the PEEK product can self-reorganize, thereby improving the stability and density of the final product, and thus improving the elongation at break and tensile strength of the 3D-printed PEEK product, making the 3D-printed PEEK product have both excellent plasticity and toughness.

[0040] Optionally, the temperature in the hot pressing step is 280-340℃, and the pressure inside the autoclave is 0.5-2.5MPa. Optionally, the temperature in the hot pressing step is 280-335℃, and the pressure inside the autoclave is 0.6-2.3MPa.

[0041] Optional, the embedding process specifically includes:

[0042] Spread a layer of embedding material at the bottom of the autoclave, place the 3D printed polyetheretherketone (PEEK) product into the autoclave, and continue to add embedding material to the autoclave until the 3D printed PEEK product is embedded within it.

[0043] Optionally, the distance between each component of the 3D printed polyetheretherketone product and the edge or bottom of the autoclave is greater than or equal to 5 mm.

[0044] Specifically, by completely encapsulating the 3D-printed polyetheretherketone (PEEK) product with embedding material, the distance between each component of the 3D-printed PEEK product and the edge and bottom of the autoclave is greater than or equal to 5mm. This helps to isolate the components of the 3D-printed PEEK product from the outside environment during heat treatment, avoiding oxidation and decarburization, and ensuring that the appearance color of the 3D-printed PEEK product does not change and the product size remains intact.

[0045] Optionally, the embedding material may include one or more of sodium chloride, zirconium oxide, glass beads, and hydroxyapatite.

[0046] Specifically, sodium chloride, zirconium oxide, glass beads, and hydroxyapatite not only act as isolation agents during heat treatment, but also ensure that the hot pressing effect penetrates fully and evenly into every microstructure of the 3D printed polyetheretherketone (PEEK) product, guaranteeing the consistency and integrity of the hot pressing effect. This, in turn, ensures that each component of the heat-treated 3D printed PEEK product has uniform elongation at break and tensile strength.

[0047] Optionally, the particle size of the embedding material is 2-4 mm.

[0048] Specifically, by controlling the particle size of the embedding material, the stability of the heat treatment effect can be ensured. If the particle size of the embedding material is too large, it may leave pits on the surface of the 3D printed polyetheretherketone (PEEK) product. If the particle size of the embedding material is too small, the particles of the embedding material may enter the pores of the 3D printed PEEK product, affecting its mechanical properties.

[0049] Optionally, after the annealing process, the 3D-printed polyetheretherketone (PEEK) product may be subjected to sandblasting to remove surface deposits, followed by cleaning and sterilization to obtain reinforced PEEK. The cleaning and sterilization processes employ commonly used techniques in the field, such as using water or anhydrous ethanol to clean the PEEK product. Sterilization is performed using high-pressure steam. Specific conditions during the cleaning and sterilization process are set according to actual working conditions to achieve the cleaning and sterilization objectives for the PEEK product; specific parameter settings are not detailed here.

[0050] Optionally, the heating rate in the hot pressing step is 10-30℃ / h.

[0051] Optionally, the hot pressing process includes: First stage: heating from room temperature to 120-150℃ at a heating rate of 10-30℃ / h, while simultaneously filling the autoclave with inert gas until the pressure inside the autoclave is 0.5-3.0MPa; Second stage: heating from 120-150℃ to 200-300℃ at a heating rate of 10-20℃ / h; Third stage: heating from 200-300℃ to 280℃-350℃ at a heating rate of 5-10℃ / h, holding at the temperature and pressure for 20-180min, and performing hot pressing on the 3D printed polyetheretherketone product.

[0052] Specifically, the temperature in the hot pressing process is strictly controlled. In the first stage, the temperature is increased from room temperature to 120-150℃ at a rate of 10-30℃ / h, while inert gas is introduced into the autoclave until the pressure inside the autoclave is 0.5-3.0MPa. During this process, the heating rate has little impact on the internal molecular structure of the 3D printed polyetheretherketone product. The faster heating rate can reduce the hot pressing cycle. The second stage involves heating from 120-150℃ to 200-300℃ at a rate of 10-20℃ / h. During this process, the molecules within the 3D-printed polyetheretherketone (PEEK) product begin to self-reorganize, but at a relatively slow rate. The third stage involves heating from 200-300℃ to 280-350℃ at a rate of 5-10℃ / h. In this application, the heating rate is gradually slowed down and strictly controlled to avoid excessively rapid temperature changes that could lead to intense molecular interactions within the 3D-printed PEEK product, resulting in structural changes (such as shrinkage deformation). Strict temperature control during the heat treatment process can more stably eliminate internal stress in the 3D-printed PEEK product, thereby improving the stability and density of the final product, and consequently improving the elongation at break and toughness of the 3D-printed PEEK product.

[0053] The technical solution of this application will be illustrated in detail below with specific embodiments. Example 1

[0054] A heat treatment method to enhance the mechanical properties of 3D printed polyetheretherketone (PEEK), such as Figure 1 As shown, the method includes the following steps:

[0055] (1) Embedding treatment: Spread a layer of embedding material at the bottom of the autoclave, put the 3D printed polyether ether ketone product into the autoclave, and continue to add embedding material to the autoclave until the 3D printed polyether ether ketone product is embedded in it;

[0056] The embedding material was selected from sodium chloride with a particle size of 2 mm.

[0057] (2) Hot pressing treatment: The temperature inside the autoclave is increased to 280℃ at a rate of 10℃ / h, and nitrogen is introduced into the autoclave at the same time until the pressure inside the autoclave is 0.5-3.0MPa. The autoclave conditions are maintained for 20 minutes to perform hot pressing treatment on the 3D printed polyether ether ketone product.

[0058] (3) Annealing treatment: The 3D printed polyether ether ketone product after hot pressing is cooled to room temperature in the furnace for annealing.

[0059] (4) Sandblast the annealed 3D printed polyether ether ketone product to remove surface deposits.

[0060] (5) The 3D printed polyether ether ketone product after sandblasting is then cleaned and sterilized to obtain reinforced 3D printed polyether ether ketone. Example 2

[0061] A heat treatment method for enhancing the mechanical properties of 3D printed polyetheretherketone (PEEK) includes the following steps:

[0062] (1) Embedding treatment: Spread a layer of embedding material at the bottom of the autoclave, put the 3D printed polyether ether ketone product into the autoclave, and continue to add embedding material to the autoclave until the 3D printed polyether ether ketone product is embedded in it;

[0063] The embedding material was selected from sodium chloride with a particle size of 2 mm.

[0064] (2) Hot pressing treatment: The temperature inside the autoclave is increased to 320℃ at a heating rate of 20℃ / h, and nitrogen is introduced into the autoclave at the same time until the pressure inside the autoclave is 0.5-2.5MPa. The autoclave conditions are maintained for 100min to perform hot pressing treatment on the 3D printed polyether ether ketone product.

[0065] (3) Annealing treatment: The 3D printed polyether ether ketone product after hot pressing is cooled to room temperature in the furnace for annealing.

[0066] (4) Sandblast the annealed 3D printed polyether ether ketone product to remove surface deposits.

[0067] (5) The 3D printed polyether ether ketone product after sandblasting is then cleaned and sterilized to obtain reinforced 3D printed polyether ether ketone. Example 3

[0068] A heat treatment method for enhancing the mechanical properties of 3D printed polyetheretherketone (PEEK) includes the following steps:

[0069] (1) Embedding treatment: Spread a layer of embedding material at the bottom of the autoclave, put the 3D printed polyether ether ketone product into the autoclave, and continue to add embedding material to the autoclave until the 3D printed polyether ether ketone product is embedded in it;

[0070] The embedding material was selected from glass spheres with a particle size of 4 mm.

[0071] (2) Hot pressing treatment: The temperature inside the autoclave is increased to 335℃ at a rate of 30℃ / h, and nitrogen is introduced into the autoclave at the same time until the pressure inside the autoclave is 0.6-2.3MPa. The autoclave conditions are maintained for 180min to perform hot pressing treatment on the 3D printed polyether ether ketone product.

[0072] (3) Annealing treatment: The 3D printed polyether ether ketone product after hot pressing is cooled to room temperature in the furnace for annealing.

[0073] (4) Sandblast the annealed 3D printed polyether ether ketone product to remove surface deposits.

[0074] (5) The 3D printed polyether ether ketone product after sandblasting is then cleaned and sterilized to obtain reinforced 3D printed polyether ether ketone. Example 4

[0075] A heat treatment method for enhancing the mechanical properties of 3D printed polyetheretherketone (PEEK) includes the following steps:

[0076] The difference from Example 2 is that:

[0077] (2) Hot pressing treatment: First stage: The temperature is increased from room temperature to 120-150℃ at a heating rate of 10℃ / h, while inert gas is introduced into the autoclave until the pressure inside the autoclave is 0.5-3.0MPa; Second stage: The temperature is increased from 120-150℃ to 200-300℃ at a heating rate of 10℃ / h; Third stage: The temperature is increased from 200-300℃ to 280℃-350℃ at a heating rate of 5℃ / h, and the temperature and pressure are maintained for 100min to perform hot pressing treatment on the 3D printed polyetheretherketone product. Example 5

[0078] A heat treatment method for enhancing the mechanical properties of 3D printed polyetheretherketone (PEEK) includes the following steps:

[0079] The difference from Example 2 is that:

[0080] (2) Hot pressing treatment: First stage: The temperature is increased from room temperature to 120-150℃ at a heating rate of 20℃ / h, while inert gas is introduced into the autoclave until the pressure inside the autoclave is 0.5-3.0MPa; Second stage: The temperature is increased from 120-150℃ to 200-300℃ at a heating rate of 15℃ / h; Third stage: The temperature is increased from 200-300℃ to 280℃-350℃ at a heating rate of 7℃ / h, and the temperature and pressure are maintained for 100min to perform hot pressing treatment on the 3D printed polyetheretherketone product. Example 6

[0081] A heat treatment method for enhancing the mechanical properties of 3D printed polyetheretherketone (PEEK) includes the following steps:

[0082] The difference from Example 2 is that:

[0083] Hot pressing treatment: First stage: Increase the temperature from room temperature to 120-150℃ at a rate of 30℃ / h, while simultaneously filling the autoclave with inert gas until the pressure inside the autoclave reaches 0.5-3.0MPa; Second stage: Increase the temperature from 120-150℃ to 200-300℃ at a rate of 20℃ / h; Third stage: Increase the temperature from 200-300℃ to 280℃-350℃ at a rate of 10℃ / h, hold at that temperature and pressure for 100min, and perform hot pressing treatment on the 3D printed polyetheretherketone (PEEK) product.

[0084] Comparative Example 1

[0085] No heat treatment is performed on 3D printed polyetheretherketone.

[0086] Comparative Example 2

[0087] A heat treatment method for enhancing the mechanical properties of 3D printed polyetheretherketone (PEEK) includes the following steps:

[0088] The difference from Example 2 is that:

[0089] (2) Hot pressing treatment: The temperature inside the autoclave is increased to 280-340℃ at a heating rate of 32℃ / h, and nitrogen is introduced into the autoclave at the same time until the pressure inside the autoclave is 0.5-2.5MPa. The autoclave conditions are maintained for 100min to perform hot pressing treatment on the 3D printed polyether ether ketone product.

[0090] Experimental Example

[0091] The 3D-printed polyetheretherketone (PEEK) products obtained in Examples 1-6, Comparative Example 1, and Comparative Example 2 were subjected to mechanical property tests, including tensile strength and elongation at break. Each test was performed in at least three parallel trials, and the average value was taken. The results are shown in Table 1.

[0092] Tensile strength was determined according to the method in GB / T1040.3-2006.

[0093] Elongation at break was determined according to the method in GB / T 1040.1-2018.

[0094] Taking Example 5 and Comparative Example 1 as examples, such as Figure 2 As shown, Figure 2 (a) is a physical image of the 3D-printed polyetheretherketone (PEEK) product provided in Comparative Example 1. Figure 2(b) is a physical image of the 3D-printed polyetheretherketone (PEEK) product provided in Example 5. Figure 2 As can be seen, the 3D printed polyetheretherketone product did not undergo any color change or shrinkage in size or other deformation due to the heat treatment method provided in this application.

[0095] Table 1

[0096] Example 1 81.45 2.95 Example 2 83.05 3.30 Example 3 83.00 3.17 Example 4 87.98 4.65 Example 5 88.95 5.81 Example 6 88.14 5.14 Comparative Example 1 75.77 1.96 Comparative Example 2 76.85 2.05

[0097] As shown in Table 1, the 3D-printed polyetheretherketone (PEEK) products obtained in Examples 1-6 all exhibit superior mechanical properties compared to Comparative Examples 1 and 2. Furthermore, comparing Examples 1-3 and Examples 4-6, the tensile strength and elongation at break of the 3D-printed PEEK products in Examples 4-6 are significantly higher than those in Examples 1-3. By strictly controlling the heating rate during the hot-pressing process, it is possible to avoid structural changes in the 3D-printed PEEK products caused by excessively rapid temperature changes. Strictly controlling the temperature during the heat treatment process can more stably eliminate internal stress in the 3D-printed PEEK products, thereby improving the stability and density of the final product, and consequently increasing the elongation at break and tensile strength.

[0098] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A heat treatment method for enhancing the mechanical properties of 3D printed polyetheretherketone (PEEK), characterized in that, Includes the following steps: (1) Embedding treatment: Place the 3D printed polyether ether ketone product into an autoclave, add embedding material to the autoclave until the 3D printed polyether ether ketone product is embedded therein; (2) Hot pressing treatment: The temperature inside the autoclave is raised to 280-350℃, and inert gas is introduced into the autoclave until the pressure inside the autoclave is 0.5-3.0MPa. The autoclave conditions are maintained for 20-180 minutes to perform hot pressing treatment on the 3D printed polyetheretherketone product. (3) Annealing treatment: The 3D printed polyether ether ketone product after hot pressing is cooled to room temperature in the furnace and annealed to obtain the reinforced 3D printed polyether ether ketone.

2. The heat treatment method for enhancing the mechanical properties of 3D printed polyetheretherketone (PEEK) according to claim 1, characterized in that, The temperature in the hot pressing process is 280-340℃, and the pressure inside the autoclave is 0.5-2.5MPa.

3. The heat treatment method for enhancing the mechanical properties of 3D printed polyetheretherketone (PEEK) according to claim 1, characterized in that, The temperature in the hot pressing process is 280-335℃, and the pressure inside the autoclave is 0.6-2.3MPa.

4. The heat treatment method for enhancing the mechanical properties of 3D printed polyetheretherketone (PEEK) according to claim 1, characterized in that, The embedding process specifically includes: A layer of embedding material is spread at the bottom of the autoclave, the 3D printed polyetheretherketone product is placed into the autoclave, and the embedding material is continued to be added to the autoclave until the 3D printed polyetheretherketone product is embedded therein.

5. The heat treatment method for enhancing the mechanical properties of 3D printed polyetheretherketone (PEEK) according to claim 4, characterized in that, The distance between each component of the 3D printed polyetheretherketone product and the edge and bottom of the autoclave is greater than or equal to 5 mm.

6. The heat treatment method for enhancing the mechanical properties of 3D printed polyetheretherketone (PEEK) according to claim 1, characterized in that, The embedding material includes one or more of sodium chloride, zirconium oxide, glass beads, and hydroxyapatite.

7. The heat treatment method for enhancing the mechanical properties of 3D printed polyetheretherketone (PEEK) according to claim 6, characterized in that, The particle size of the embedding material is 2-4 mm.

8. The heat treatment method for enhancing the mechanical properties of 3D printed polyetheretherketone (PEEK) according to claim 5, characterized in that, After the annealing process is completed, the process further includes: sandblasting the annealed 3D printed polyether ether ketone product to remove surface deposits, followed by cleaning and sterilization to obtain reinforced 3D printed polyether ether ketone.

9. The heat treatment method for enhancing the mechanical properties of 3D printed polyetheretherketone (PEEK) according to claim 8, characterized in that, The heating rate in the hot pressing process is 10-30℃ / h.

10. The heat treatment method for enhancing the mechanical properties of 3D printed polyetheretherketone (PEEK) according to any one of claims 1-9, characterized in that, The hot-pressing process includes: a first stage: heating from room temperature to 120-150℃ at a rate of 10-30℃ / h, while simultaneously filling the autoclave with inert gas until the pressure inside the autoclave is 0.5-3.0MPa; a second stage: heating from 120-150℃ to 200-300℃ at a rate of 10-20℃ / h; and a third stage: heating from 200-300℃ to 280℃-350℃ at a rate of 5-10℃ / h, holding at the temperature and pressure for 20-180 minutes to perform hot-pressing on the 3D printed polyetheretherketone (PEEK) product.

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