Titanium molybdenum alloy material formed by slm and preparation method thereof

Abstract

This invention relates to a titanium-molybdenum alloy material formed by SLM (Surface Mount Technology) and its preparation method. The alloy material is made from titanium-molybdenum alloy powder and 3D printed by SLM. The alloy material comprises the following components by weight percentage: molybdenum 16%-25%, Fe≤0.076%, C≤0.01%, N≤0.016%, O≤0.072%, N≤0.002%, with the remainder being titanium. The molybdenum is selected from non-spherical ultrafine molybdenum powder particles with a particle size of less than 5μm. In this invention, the mechanical properties of the alloy are improved by reinforcing with molybdenum powder. The use of non-spherical ultrafine molybdenum powder particles can lower the melting point of molybdenum, combining fluidity with good printing performance, making the titanium-molybdenum alloy powder suitable for SLM forming equipment with lower power.

Description

Technical Field

[0001] This invention relates to the field of alloy material manufacturing technology, specifically to a titanium-molybdenum alloy material and its preparation method. Background Technology

[0002] Titanium alloys, as a widely used metallic material, possess characteristics such as low density, high specific strength, strong corrosion resistance, and good biocompatibility, and have been widely applied in fields such as biomedical materials, the automotive industry, and the aerospace industry. However, titanium alloys themselves have low thermal conductivity and low elastic modulus, making them difficult to machine, which severely limits their application in various fields.

[0003] In recent years, 3D printing technologies such as SLM (Surface Mount Technology) have achieved near-net-shape parts with high density through additive manufacturing, meeting requirements that traditional processes such as turning, forging, and casting cannot achieve. This method offers a new solution for the rapid manufacturing of complex titanium alloy components due to its advantages such as high processing freedom, no limitation by part complexity, and high material utilization. However, titanium-based alloy formed parts manufactured by SLM face challenges compared to traditional forgings and castings, including poor plasticity and low tensile elongation. Furthermore, the V, Al, and Ni components in the material powder are highly toxic, making them unsuitable for clinical applications such as implants or dental orthodontics. Summary of the Invention

[0004] To address the aforementioned issues, this invention proposes a titanium-molybdenum alloy material formed by SLM and its preparation method. This alloy is composed of Ti and Mo and does not contain toxic substances such as Al, V, and Ni. It can rapidly obtain in-situ heat-treated parts during the SLM process, which is better than commonly used traditional sintering methods. Furthermore, the titanium-molybdenum alloy has good biocompatibility and can be used in the biomedical field.

[0005] To achieve the above objectives, the present invention employs the following technical solution: In a first aspect of the present invention, a titanium-molybdenum alloy material formed by SLM is provided, which is made of titanium-molybdenum alloy powder and formed by SLM 3D printing. The alloy material comprises the following components by weight percentage: molybdenum 16%-25%, Fe≤0.076%, C≤0.01%, N≤0.016%, O≤0.072%, N≤0.002%, and the remainder is titanium; the molybdenum is selected from non-spherical ultrafine molybdenum powder particles with a particle size of less than 5μm.

[0006] Preferably, the titanium is titanium powder particles with a purity of 99.8% and a particle size of 15-53μm.

[0007] Preferably, the titanium powder particles comprise the following components by weight percentage: Fe≤0.076%, C≤0.01%, N≤0.016%, H≤0.001%, O≤0.072%, with the remainder being Ti.

[0008] Preferably, the molybdenum powder particles comprise the following components by weight percentage: H≤0.002%, N≤0.002%, Fe≤0.032%, O≤0.18%, C≤0.015%, with the remainder being Mo.

[0009] Preferably, the tensile strength of the titanium-molybdenum alloy material is 835 MPa.

[0010] In a second aspect of the present invention, a method for preparing SLM-molded titanium-molybdenum alloy material is provided, comprising the following steps: Step 1, mixing powder to prepare titanium-based alloy powder: taking 16%-25% by weight of molybdenum powder, with the remainder being titanium powder, and placing it in a planetary ball mill at a ball-to-powder ratio of 1:1, a rotation speed of 150 r / min, and a rotation time of 1 hour, using the mixed titanium-molybdenum alloy powder as the raw material for 3D printing; Step 2, SLM molding to prepare titanium-molybdenum alloy material: drawing a three-dimensional solid model using computer software, and slicing the three-dimensional solid model into layers using slicing software; and inputting the sliced ​​files... The titanium substrate is installed in the 3D printer's forming chamber. The prepared titanium-molybdenum alloy powder is loaded into the powder cylinder, the titanium substrate is leveled, and a layer of composite powder is evenly spread on the substrate. The forming chamber is sealed, the argon valve is opened, and a certain amount of argon gas is filled. Under the protection of inert gas, the titanium alloy powder bed is selectively scanned and melted by laser. After each layer is scanned, the substrate is lowered by one layer thickness, the powder cylinder is raised by one layer thickness, and a scraper is used to reciprocate to lay up a new layer of titanium alloy powder. This operation is repeated until all preset slices are completed, and titanium-molybdenum alloy material of the target size and shape is obtained by layer-by-layer deposition.

[0011] Preferably, 20% by weight of molybdenum powder and 80% by weight of titanium powder are used.

[0012] Preferably, in the second step of the processing, the laser is controlled to complete the entire process using a cross-scanning method, with the laser power being 150-190W and the scanning speed being 400-1000mm / s.

[0013] Preferably, in the second step of the processing, the thickness of each titanium alloy powder layer is 20 to 50 micrometers, and the laser scanning direction of the upper and lower layers is rotated by 67°.

[0014] Preferably, the oxygen content in the forming chamber is less than 1000 ppm during the second step of the processing.

[0015] This invention effectively addresses the problems of high toxicity in SLM-formed titanium alloy materials and poor tensile strength in pure titanium SLM, resulting in materials with stronger tensile properties and greater suitability for medical applications closely related to the human body, particularly in implants and orthodontic treatment. Compared with existing technologies, the advantages and positive effects of this invention are as follows: This invention stabilizes the β phase of titanium alloys through molybdenum powder reinforcement, significantly improving the alloy's mechanical properties, especially in maintaining certain strain conditions and biocompatibility while enhancing tensile strength. The invention utilizes non-spherical ultrafine molybdenum powder particles, which lower the melting point of molybdenum and combine fluidity with good printing performance. This makes the titanium-molybdenum alloy powder suitable for lower-power SLM molding equipment, enabling selective area molding of titanium-molybdenum alloys under lower power conditions (below 200W), greatly enhancing the competitiveness of lower-power printing equipment. Attached Figure Description

[0016] Figure 1 Scanning electron microscope image of titanium-molybdenum alloy powder.

[0017] Figure 2 This is a scanning electron microscope image of titanium powder (gray area).

[0018] Figure 3 A scanning electron microscope image of molybdenum powder (gray area).

[0019] Figure 4 for Figure 1 The energy density gradient screening results for titanium-molybdenum alloy materials (the best group is shown in gray).

[0020] Figure 5 for Figure 1 Tensile results of tensile specimens prepared from molybdenum powder alloy material. Detailed Implementation

[0021] To better understand the technical solution of this invention, the content of this invention includes, but is not limited to, the specific embodiments described below. Similar technologies and methods should be considered within the scope of protection of this invention. To make the technical problems to be solved, the technical solutions, and advantages of this invention clearer, a detailed description will be provided below in conjunction with the accompanying drawings and specific embodiments.

[0022] The SLM-formed titanium-molybdenum alloy material in this embodiment is shown in the scanning electron microscope image as follows: Figure 1As shown, the material is 3D printed using titanium-molybdenum alloy powder via SLM molding. The alloy material comprises the following components by weight percentage: molybdenum 16%-25%, Fe≤0.076%, C≤0.01%, N≤0.016%, O≤0.072%, N≤0.002%, with the remainder being titanium. The titanium used is titanium powder with a purity of 99.8% and a particle size of 15-53 μm. A scanning electron microscope image of the titanium powder (gray area) is shown below. Figure 2 As shown. The molybdenum is selected from non-spherical ultrafine molybdenum powder particles with a particle size of less than 5 μm. A scanning electron microscope image of the molybdenum powder (gray area) is shown below. Figure 3 As shown.

[0023] Pure titanium (Ti) exhibits excellent deformability at room temperature, but its strength is relatively low, which greatly limits the application range of titanium alloys. Molybdenum (Mo), as a β-stabilizing element, not only strongly stabilizes the β phase and improves the mechanical properties of the alloy, but also enhances the corrosion resistance of titanium alloys.

[0024] Further, the titanium powder particles comprise the following weight percentage components: Fe≤0.076%, C≤0.01%, N≤0.016%, H≤0.001%, O≤0.072%, with the remainder being Ti. The molybdenum powder particles comprise the following weight percentage components: H≤0.002%, N≤0.002%, Fe≤0.032%, O≤0.18%, C≤0.015%, with the remainder being Mo. The uniform spherical particle size variation of the titanium powder can increase the powder's stacking density and powder flowability during SLM scanning. The ultrafine non-spherical molybdenum powder can lower the melting point of molybdenum, allowing for better bonding between the two powders. This combination of flowability and good printing performance makes the titanium-molybdenum alloy powder suitable for lower-power SLM forming equipment, enabling selective forming of titanium-molybdenum alloys under lower power conditions (below 200W), significantly improving the competitiveness of lower-power printing equipment.

[0025] The method for preparing SLM-formed titanium-molybdenum alloy material according to this embodiment specifically includes the following steps: Step 1: Preparation of Titanium-Based Alloy Powder through Powder Mixing: Take 16%-25% by weight of molybdenum powder, with the remainder being titanium powder. Place the mixture in a planetary ball mill at a ball-to-powder ratio of 1:1, add zirconia balls, and rotate at 150 rpm for 1 hour. Use the resulting titanium-molybdenum alloy powder as the raw material for 3D printing. The raw materials selected are titanium and molybdenum powders with micron-sized particle sizes. The titanium powder particles have a diameter of 15-53 μm, and the molybdenum powder particles have a diameter ≤5 μm and are non-spherical.

[0026] Under the splitting and repeated mixing of zirconia spheres, the powder undergoes collisions, impacts, and friction, ensuring continuous and uniform mixing of molybdenum and titanium powders. Low-intensity, short-duration rotary mixing further homogenizes and refines the powder, ultimately resulting in a composite powder with a uniformly dispersed distribution of the additive phase. Traditional methods struggle to prepare dispersion-strengthened titanium-molybdenum alloys, while 3D printing allows for rapid production of samples with the desired shape through direct molding and controllable properties. Furthermore, the sphericity of the powder particles can be controlled by varying the mixing time.

[0027] The second step, SLM molding and preparation of titanium-molybdenum alloy material: A three-dimensional solid model is drawn using computer software, and the three-dimensional solid model is sliced ​​into layers using slicing software; the sliced ​​file is input into the 3D printer, a titanium substrate is installed in the molding chamber of the 3D printer, the prepared titanium-molybdenum alloy powder is loaded into the powder cylinder, the titanium substrate is leveled, and a layer of composite powder is evenly spread on the substrate, the molding chamber is sealed, the argon valve is opened, and a certain amount of argon is filled to make the molding chamber full of argon with an oxygen content of less than 1000ppm.

[0028] The layered and sliced ​​files were imported into the SLM printing equipment, and the SLM forming process parameters were set. The SLM processing parameter range was preset based on the composition ratio of the mixed alloy powder, and adaptation tests were conducted to determine the ideal processing parameters for the target sample. Furthermore, using laser power, scanning speed, and powder layer thickness as variables, the SLM forming strategy was set based on the gradient change of energy density within the preset laser power and scanning speed parameter range. Using 20% ​​molybdenum powder and 80% titanium powder by weight, the energy density gradient changes of 14 samples are shown below. Figure 4 As shown.

[0029] After extensive screening of parameters and proportions, tensile tests were conducted on the best-performing samples. The laser power was 150–190 W, the scanning speed was 400–1000 mm / s, the thickness of each titanium alloy powder layer was 20–50 μm, preferably 30–50 μm, and the laser scanning direction of the upper and lower layers was rotated by 67°.

[0030] In an inert gas protected environment, a laser is used to selectively scan and melt the titanium alloy powder bed. After each layer is scanned, the substrate is lowered by one layer thickness, the powder feeding cylinder is raised by one layer thickness, and a scraper is used to reciprocate to lay up a new layer of titanium alloy powder. During the processing, the laser is controlled to use a cross-scanning method to complete the entire process. This operation is repeated until all preset slices are completed, and titanium-molybdenum alloy material of the target size and shape is obtained by layer-by-layer deposition.

[0031] Based on the tensile test results of the samples obtained above, the processing parameters that yielded the most ideal results from the energy density gradient change test were selected, such as... Figure 4 As shown, the optimal energy density for the sample is 100 J / mm².3 (Shown in gray in the figure), refining the samples under these processing parameters can yield an optimal low-power printing ideal parameter.

[0032] The 3D-printed sample of titanium-molybdenum alloy material formed by SLM in this embodiment has a smooth surface, obvious metallic luster, no cracks on the sample surface, and improved tensile strength. Figure 5 The strain-stress curves show that the tensile strength of the titanium-molybdenum alloy material is increased to 835 MPa (e.g., Figure 5 The vertical axis shows the peak stress. Ordinary pure titanium typically has a tensile strength of 400 MPa.

[0033] This invention effectively addresses the problems of high toxicity in SLM-formed titanium alloy materials and poor tensile strength in pure titanium SLM, enabling the material to achieve stronger tensile properties and making it more suitable for medical applications closely related to the human body, especially clinical applications in human implants or dental orthodontics.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Those skilled in the art can modify the technical solutions described in the present invention, or make equivalent substitutions for some of the technical features, and these modifications or substitutions do not cause the corresponding technical solutions to deviate from the scope of the present invention.

Claims

1. A titanium-molybdenum alloy material formed by SLM, characterized in that: The alloy is made of titanium-molybdenum alloy powder and 3D printed by SLM molding. The alloy material includes the following components by weight percentage: molybdenum 16%-25%, Fe≤0.076%, C≤0.01%, N≤0.016%, O≤0.072%, N≤0.002%, and the remainder is titanium. The molybdenum is selected from non-spherical ultrafine molybdenum powder particles with a particle size of less than 5μm.

2. The SLM-formed titanium-molybdenum alloy material according to claim 1, characterized in that: The titanium used is titanium powder particles with a purity of 99.8% and a particle size of 15-53μm.

3. The SLM-formed titanium-molybdenum alloy material according to claim 2, characterized in that: The titanium powder particles comprise the following components by weight percentage: Fe≤0.076%, C≤0.01%, N≤0.016%, H≤0.001%, O≤0.072%, with the remainder being Ti.

4. The SLM-formed titanium-molybdenum alloy material according to claim 1, characterized in that: The molybdenum powder particles comprise the following components by weight percentage: H≤0.002%, N≤0.002%, Fe≤0.032%, O≤0.18%, C≤0.015%, with the remainder being Mo.

5. The SLM-formed titanium-molybdenum alloy material according to claim 1, characterized in that: The tensile strength of the titanium-molybdenum alloy material is 835 MPa.

6. The method for preparing an SLM-formed titanium-molybdenum alloy material according to claim 1, characterized in that: Includes the following steps: Step 1: Powder Mixing and Preparation of Titanium-Based Alloy Powder: Take 16%-25% by weight of molybdenum powder, with the remainder being titanium powder, and place it in a planetary ball mill at a ball-to-powder ratio of 1:1, a rotation speed of 150 r / min, and a rotation time of 1 hour. Use the mixed titanium-molybdenum alloy powder as the raw material for 3D printing. Step 2: SLM Molding and Preparation of Titanium-Molybdenum Alloy Material: Use computer software to create a 3D solid model, and use slicing software to slice the 3D solid model into layers. Input the sliced ​​file into the 3D printer, and install it in the 3D printer's forming chamber. The titanium substrate is prepared by loading titanium-molybdenum alloy powder into a powder cylinder, leveling the titanium substrate, and uniformly spreading a layer of composite powder on the substrate. The molding chamber is sealed, the argon valve is opened, and a certain amount of argon gas is filled. Under the protection of inert gas, the titanium alloy powder bed is selectively scanned and melted by laser. After each layer is scanned, the substrate is lowered by one layer thickness, the powder cylinder is raised by one layer thickness, and a new titanium alloy powder layer is laid by reciprocating motion of a scraper. This operation is repeated until all preset slices are completed, and titanium-molybdenum alloy material of the target size and shape is obtained by layer-by-layer deposition.

7. The preparation method according to claim 6, characterized in that: Take 20% by weight of molybdenum powder and 80% by weight of titanium powder.

8. The preparation method according to claim 6, characterized in that: In the second step of the processing, the laser is controlled to complete the entire process using a cross-scanning method. The laser power is 150-190W and the scanning speed is 400-1000mm / s.

9. The preparation method according to claim 6, characterized in that: In the second step of the processing, the thickness of each titanium alloy powder layer is 20 to 50 micrometers, and the laser scanning direction of the upper and lower layers is rotated by 67°.

10. The preparation method according to claim 6, characterized in that: During the second step of the processing, the oxygen content in the forming chamber is less than 1000 ppm.

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