Titanium alloy material for inhibiting beta-fleck defect through uniform doping of nano iron powder as well as preparation method and application of titanium alloy material
Through the preparation method of titanium alloy material with uniformly doped nano iron powder, the problem of β-fleck defect in laser powder bed melting process is solved, and the high density and high performance application of the material is achieved, especially in human implants in the field of biomedical medicine.
Patent Information
- Application Number
- CN202510667794.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-22
- Publication Date
- 2025-08-15
AI Technical Summary
In the laser powder bed melt additive manufacturing process, titanium alloy materials are prone to form β-fleck defects, resulting in uneven mechanical properties of the material and the initiation of fatigue cracks, which are difficult to effectively suppress in the prior art.
Using a titanium alloy material with uniformly doped nano-iron powder, the nano-iron powder is mixed with micro-spherical titanium powder under an inert gas atmosphere, and printed layer by layer using an additive manufacturing process. The process parameters are controlled to ensure that the nano-iron powder is uniformly diffused in the titanium matrix and avoid local iron segregation and brittle TiFe precipitation phase.
It achieves the composition uniformity and high consistency of microstructure of titanium alloy materials, avoids β-fleck defects, improves the density and mechanical properties of the materials, and is suitable for high-end manufacturing and biomedical fields.
Smart Images
Figure CN120485595A_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the technical field of additive manufacturing of metal materials, and in particular relates to a titanium alloy material in which β-fleck defects are suppressed by uniformly doping with nano-iron powder, and a preparation method and application thereof. Background Art
[0002] In additive manufacturing processes such as laser powder bed fusion (LPBF), titanium alloys (such as pure titanium and Ti-6Al-4V) are prone to element segregation due to their rapid solidification characteristics, forming localized β-phase-enriched regions (β-fleck). This defective region, due to its uneven composition distribution, leads to significant fluctuations in the material's mechanical properties (such as decreased tensile strength and increased brittleness), and becomes a source of fatigue crack initiation, seriously restricting the reliability and service life of titanium alloy components.
[0003] At present, some technologies control the composition by adding micron-sized β-stabilizing element (such as Fe, Mo) powder. However, due to the large particle size (>10μm), its diffusion efficiency in the molten pool is insufficient, which aggravates the segregation of iron elements and forms β-fleck defects. There are also technologies that use pre-alloyed powder for preparation. Although it can alleviate the problem of composition segregation, it has defects such as high raw material cost and low composition flexibility, which makes it difficult to meet customized needs.
[0004] Therefore, there is an urgent need to provide a new titanium alloy material to suppress β-fleck defects, so that the titanium alloy material can be used for the manufacture of precision components in multiple fields. Summary of the Invention
[0005] The purpose of this application is to provide a titanium alloy material that suppresses β-fleck defects by uniformly doping with nano-iron powder, as well as its preparation method and application, aiming to solve the problem in the prior art that titanium alloy materials are prone to β-fleck defects in additive manufacturing processes.
[0006] To achieve the above application objectives, the technical solutions adopted in this application are as follows:
[0007] In a first aspect, the present application provides a titanium alloy material that suppresses β-fleck defects by uniformly doping with nano-iron powder. The titanium alloy material uses micron-spherical titanium powder as a substrate, and nano-iron powder is uniformly distributed inside the substrate; wherein, based on the total mass of the titanium alloy material as 100%, the nano-iron powder is 0.5-2.0wt% and the micron-spherical titanium powder is 98-99.5wt%.
[0008] In some embodiments, the nano iron powder has a particle size of 300-500 nm and a purity of ≥99.5%.
[0009] In some embodiments, the micron spherical titanium powder has a particle size of 15-53 μm and a purity of ≥99.9%.
[0010] In some embodiments, the titanium alloy material includes the following features:
[0011] (a) Density ≥ 99.98%, no β-fleck defect;
[0012] (b) The β phase is evenly distributed in the microstructure, and there is no TiFe precipitation phase;
[0013] (c) Ultimate tensile strength ≥940 MPa, fracture strain ≥17%.
[0014] In a second aspect, the present application provides a method for preparing a titanium alloy material that suppresses β-fleck defects by uniformly doping with nano-iron powder, comprising the following steps:
[0015] In an inert gas atmosphere, nano iron powder and micron spherical titanium powder are uniformly mixed according to mass percentage to obtain a mixed powder;
[0016] The mixed powder is printed layer by layer using an additive manufacturing process to obtain a titanium alloy material.
[0017] In some embodiments, in the step of uniformly mixing the nano-iron powder and the micron-shaped spherical titanium powder according to mass percentage, a three-dimensional powder mixer is used to process the mixture at a rotation speed of 100-150 rpm for 6-8 hours.
[0018] In some embodiments, the inert gas atmosphere includes at least one of an argon gas atmosphere, a nitrogen gas atmosphere, and a helium gas atmosphere; and in the inert gas atmosphere, an oxygen concentration is ≤100 ppm.
[0019] In some embodiments, the process parameters of the additive manufacturing process include: substrate preheating temperature of 200-220°C, laser power of 100-400W, scanning speed of 600-1500mm / s, layer thickness of 0.03-0.05mm, and scanning spacing of 0.105-0.110mm.
[0020] In some embodiments, during the layer-by-layer printing step, the printing path of each layer is rotated 90° clockwise based on the previous layer, and a "striped" pattern is adopted.
[0021] In some embodiments, the dimensions of the titanium alloy material are: 24-26 mm in length, 13-15 mm in width, and 2.5-3 mm in thickness.
[0022] In a third aspect, the present application provides an application of a titanium alloy material in the biomedical field in which β-fleck defects are suppressed by uniformly doping with nano-iron powder.
[0023] The first aspect of the present application provides a titanium alloy material that suppresses β-fleck defects by uniformly doping with nano-iron powder. The titanium alloy material uses micron-shaped spherical titanium powder as a substrate, and nano-iron powder is uniformly distributed inside the substrate. Due to the small size and large specific surface area of the nano-iron powder, it quickly dissolves and evenly diffuses into the titanium matrix during the laser powder bed melting process, avoiding the problem of local iron element segregation caused by insufficient diffusion of the micron iron powder. At the same time, the nano-iron powder diffuses quickly and avoids local iron enrichment, ensuring that there is no β-phase enriched area (β-fleck) and brittle TiFe precipitation phase. The high surface activity of the nano-iron powder enhances the wettability of the molten pool, promotes melt flow and pore filling, avoids unfused defects, and is beneficial to improving the density of the product. In addition, it is low in cost and highly practical, providing a solution for the application of high-performance titanium alloys in the field of high-end manufacturing, which is beneficial to the widespread application of titanium alloy materials.
[0024] The second aspect of the present application provides a preparation process for a titanium alloy material that suppresses β-fleck defects by uniformly doping with nano-iron powder. The raw materials are first mixed evenly, and then the mixed powder is printed layer by layer using an additive manufacturing process. This is beneficial to improving the doping uniformity of the nano-iron powder. At the same time, by controlling the various process parameters of the additive manufacturing process, the stable diffusion of the nano-iron powder under complex thermal cycles is ensured; it is ensured that the titanium alloy doped with nano-iron powder has no β-phase enriched area (β-fleck) and brittle TiFe precipitation phase, and the microstructure is highly uniform, so as to improve the overall properties of the titanium alloy material. Moreover, the preparation process is simple, does not require the use of large instruments and equipment, and is conducive to large-scale application.
[0025] The third aspect of the present application provides an application of a titanium alloy material in the biomedical field that suppresses β-fleck defects by uniformly doping with nano-iron powder. The titanium alloy material provided above has the characteristics of high composition uniformity, no β-fleck defects, and high strength and plasticity. Therefore, it can be widely used in the biomedical field, especially suitable for human implants (such as bone screws, joint prostheses), to avoid in vivo corrosion or fatigue failure caused by uneven composition. Therefore, the titanium alloy material in the biomedical field that suppresses β-fleck defects by uniformly doping with nano-iron powder has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.
[0027] Figure 1These are SEM images of the pure titanium powder, micron iron powder, and the Ti-Fe mixed powder containing nano iron powder obtained in Example 1 provided in the examples of the present application.
[0028] Figure 2 This is an EDX image of the Ti-Fe mixed powder containing nano-iron powder provided in the examples of the present application.
[0029] Figure 3 The comparative example 1 provided in this application contains a Ti-Fe mixed powder of micron iron powder (such as Figure 3 a) and the Ti-Fe mixed powder containing nano iron powder in Example 1 (such as Figure 3 b) SEM image of the prepared titanium alloy.
[0030] Figure 4 These are EBSD analysis diagrams of the Ti-Fe mixed powder comprising micron iron powder in Comparative Example 1 and the Ti-Fe mixed powder comprising nanometer iron powder in Example 1 provided in this application. DETAILED DESCRIPTION
[0031] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.
[0032] In this application, the term "and / or" describes the relationship between associated objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.
[0033] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.
[0034] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. Some or all of the steps can be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.
[0035] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.
[0036] The weights of the relevant components mentioned in the examples of this application may not only refer to the specific content of each component, but also represent the weight ratio between the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the examples of this application, it is within the scope disclosed in the examples of this application. Specifically, the mass in the examples of this application may be μg, mg, g, kg, etc., which are mass units known in the chemical industry.
[0037] The terms "first" and "second" are used solely for descriptive purposes to distinguish objects, such as substances, from one another and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the technical features being referred to. For example, a first XX could also be referred to as a second XX, and similarly, a second XX could also be referred to as a first XX, without departing from the scope of the embodiments of this application. Thus, features defined as "first" or "second" may explicitly or implicitly include one or more of such features.
[0038] A first aspect of an embodiment of the present application provides a titanium alloy material that suppresses β-fleck defects by uniformly doping with nano-iron powder. The titanium alloy material uses micron-shaped spherical titanium powder as a substrate, and the nano-iron powder is uniformly distributed inside the substrate. Particularly, based on the total mass of the titanium alloy material as 100%, the nano-iron powder accounts for 0.5-2.0wt% and the micron-shaped spherical titanium powder accounts for 98-99.5wt%.
[0039] The first aspect of the embodiment of the present application provides a titanium alloy material that suppresses β-fleck defects by uniformly doping with nano-iron powder. The titanium alloy material uses micron-shaped spherical titanium powder as a substrate, and nano-iron powder is uniformly distributed inside the substrate. Due to the small size and large specific surface area of the nano-iron powder, it quickly dissolves and evenly diffuses into the titanium matrix during the laser powder bed melting process, avoiding the problem of local iron element segregation caused by insufficient diffusion of the micron iron powder. At the same time, the nano-iron powder has a fast diffusion speed and avoids local iron enrichment, ensuring that there is no β-phase enriched area (β-fleck) and brittle TiFe precipitation phase. The high surface activity of the nano-iron powder enhances the wettability of the molten pool, promotes melt flow and pore filling, avoids unfused defects, and is beneficial to improving the density of the product. In addition, it is low in cost and highly practical, providing a solution for the application of high-performance titanium alloys in the field of high-end manufacturing, which is beneficial to the widespread application of titanium alloy materials.
[0040] In some embodiments, the amount of nano-iron powder added includes, but is not limited to, typical but non-limiting values such as 0.5 wt%, 0.8 wt%, 1.0 wt%, 1.2 wt%, 1.5 wt%, 1.8 wt%, and 2.0 wt%, based on the total mass of the titanium alloy material as 100%. If the amount of nano-iron powder added is too much, the alloy plasticity will be severely damaged; if the amount of nano-iron powder added is too little, the strength will be too low and will not meet the requirements for industrial use.
[0041] In some embodiments, based on the total mass of the titanium alloy material as 100%, the added amount of micron spherical titanium powder includes but is not limited to typical but non-limiting values such as 98wt%, 98.2wt%, 98.5wt%, 98.8wt%, 99wt%, 99.2wt%, and 99.5wt%.
[0042] In some embodiments, the nano iron powder has a particle size of 300-500 nm and a purity of ≥99.5%. In some specific embodiments, the particle size of the nano iron powder includes, but is not limited to, typical but non-limiting values such as 300 nm, 320 nm, 350 nm, 380 nm, 400 nm, 420 nm, 450 nm, 480 nm, and 500 nm.
[0043] In some embodiments, the micron spherical titanium powder has a particle size of 15-53 μm and a purity of ≥99.9%. In some specific embodiments, the particle size of the micron spherical titanium powder includes, but is not limited to, typical but non-limiting values such as 15 μm, 17 μm, 20 μm, 22 μm, 25 μm, 27 μm, 30 μm, 32 μm, 35 μm, 37 μm, 40 μm, 42 μm, 45 μm, 47 μm, 50 μm, and 53 μm.
[0044] In some embodiments, the titanium alloy material includes the following features:
[0045] (a) Density ≥ 99.98%, no β-fleck defect;
[0046] (b) The β phase is evenly distributed in the microstructure, and there is no TiFe precipitation phase;
[0047] (c) Ultimate tensile strength ≥940 MPa, fracture strain ≥17%.
[0048] A second aspect of the present invention provides a method for preparing a titanium alloy material by uniformly doping with nano-iron powder to suppress β-fleck defects, comprising the following steps:
[0049] S01 in an inert gas atmosphere, the nano-iron powder and micron spherical titanium powder are uniformly mixed by mass percentage to obtain a mixed powder;
[0050] S02. Print the mixed powder layer by layer using an additive manufacturing process to obtain a titanium alloy material.
[0051] The second aspect of the embodiment of the present application provides a preparation process for a titanium alloy material that suppresses β-fleck defects by uniformly doping with nano-iron powder. The raw materials are first mixed evenly, and then the mixed powder is printed layer by layer using an additive manufacturing process. This is beneficial to improving the doping uniformity of the nano-iron powder. At the same time, by controlling the various process parameters of the additive manufacturing process, the stable diffusion of the nano-iron powder under complex thermal cycles is ensured; it is ensured that the titanium alloy doped with nano-iron powder has no β-phase enriched area (β-fleck) and brittle TiFe precipitation phase, and the microstructure is highly uniform, so as to improve the overall properties of the titanium alloy material. Moreover, the preparation process is simple, does not require the use of large instruments and equipment, and is conducive to large-scale application.
[0052] In step S01 , nano iron powder and micron spherical titanium powder are uniformly mixed according to mass percentage under an inert gas atmosphere to obtain a mixed powder.
[0053] In some embodiments, in the step of uniformly mixing the nano-iron powder and the micron-shaped spherical titanium powder according to mass percentage, a three-dimensional powder mixer is used to process the mixture at a rotation speed of 100-150 rpm for 6-8 hours.
[0054] In some embodiments, the inert gas atmosphere includes at least one of an argon gas atmosphere, a nitrogen gas atmosphere, and a helium gas atmosphere; and in the inert gas atmosphere, an oxygen concentration is ≤100 ppm.
[0055] In step S02, the mixed powder is printed layer by layer using an additive manufacturing process to obtain a titanium alloy material.
[0056] In some embodiments, the process parameters of the additive manufacturing process include: substrate preheating temperature of 200-220°C, laser power of 100-400W, scanning speed of 600-1500mm / s, layer thickness of 0.03-0.05mm, and scanning spacing of 0.105-0.110mm.
[0057] In some specific embodiments, the substrate preheating temperature includes, but is not limited to, typical but non-limiting values such as 200° C., 205° C., 210° C., 215° C., and 220° C.
[0058] In some specific embodiments, the laser power includes, but is not limited to, typical but non-limiting values such as 100 W, 150 W, 200 W, 250 W, 300 W, 350 W, and 400 W. If the laser power is too high, the sample may warp, and if the laser power is too low, excessive voids may result.
[0059] In some specific embodiments, the scanning speed includes but is not limited to typical but non-limiting values such as 600 mm / s, 700 mm / s, 800 mm / s, 900 mm / s, 1000 mm / s, 1100 mm / s, 1200 mm / s, 1300 mm / s, 1400 mm / s, and 1500 mm / s.
[0060] In some specific embodiments, the layer thickness includes, but is not limited to, typical but non-limiting values such as 0.03 mm, 0.035 mm, 0.04 mm, 0.045 mm, and 0.05 mm.
[0061] In some specific embodiments, the scanning pitch includes, but is not limited to, typical but non-limiting values such as 0.105 mm, 0.106 mm, 0.107 mm, 0.108 mm, 0.109 mm, and 0.110 mm.
[0062] In some specific embodiments, the process parameters of the additive manufacturing process include: substrate preheating temperature of 200° C., laser power of 250 W, scanning speed of 1000 mm / s, layer thickness of 0.04 mm, and scanning spacing of 0.105 mm.
[0063] In some embodiments, during the layer-by-layer printing step, the printing path of each layer is rotated 90° clockwise based on the previous layer, and a "striped" pattern is adopted.
[0064] In some embodiments, the dimensions of the titanium alloy material are: 24-26 mm in length, 13-15 mm in width, and 2.5-3 mm in thickness.
[0065] In some specific embodiments, the dimensions of the titanium alloy material are: 24 mm in length, 13 mm in width, and 2.5 mm in thickness.
[0066] A third aspect of the embodiments of the present application provides an application of a titanium alloy material in the biomedical field in which β-fleck defects are suppressed by uniform doping with nano-iron powder.
[0067] The third aspect of the embodiment of the present application provides an application of a titanium alloy material in the biomedical field that suppresses β-fleck defects by uniformly doping with nano-iron powder. The titanium alloy material provided above has the characteristics of high composition uniformity, no β-fleck defects, and high strength and plasticity. Therefore, it can be widely used in the biomedical field, especially suitable for human implants (such as bone screws, joint prostheses), to avoid in vivo corrosion or fatigue failure caused by uneven composition. Therefore, the titanium alloy material in the biomedical field that suppresses β-fleck defects by uniformly doping with nano-iron powder has a wide range of applications.
[0068] The following describes the details in conjunction with specific embodiments.
[0069] Example 1
[0070] A titanium alloy material that suppresses β-fleck defects by uniformly doping with nano-iron powder. The titanium alloy material uses micron-shaped spherical titanium powder as a substrate, and the nano-iron powder is uniformly distributed inside the substrate. Specifically, based on the total mass of the titanium alloy material being 100%, the nano-iron powder accounts for 1wt% and the micron-shaped spherical titanium powder accounts for 99wt%. The nano-iron powder has a particle size of 300nm and a purity of 99.7%. The micron-shaped spherical titanium powder has a particle size of 15μm and a purity of 99.95%.
[0071] The preparation method comprises the following steps:
[0072] Provide an argon gas atmosphere, where the oxygen concentration is ≤100ppm;
[0073] Nano iron powder and micron spherical titanium powder were mixed according to the mass percentages provided in Example 1, and processed in a three-dimensional powder mixer at a speed of 150 rpm for 3 hours to obtain a mixed powder;
[0074] The mixed powder is printed layer by layer using an additive manufacturing process to obtain a titanium alloy material. The process parameters of the additive manufacturing process include: substrate preheating temperature of 200°C, laser power of 250W, scanning speed of 1000mm / s, layer thickness of 0.04mm, and scanning spacing of 0.105mm. In the layer-by-layer printing step, the printing path of each layer is rotated 90° clockwise based on the previous layer, and a "striped" mode is adopted.
[0075] Performance test: The obtained titanium alloy material has an ultimate tensile strength of 940 MPa and a fracture strain of 17%; there is no β-fleck defect; the β phase is evenly distributed in the microstructure, and there is no TiFe precipitation phase.
[0076] Example 2
[0077] A titanium alloy material that suppresses β-fleck defects by uniformly doping with nano-iron powder. The titanium alloy material uses micron-shaped spherical titanium powder as a substrate, and the nano-iron powder is uniformly distributed inside the substrate. Specifically, based on the total mass of the titanium alloy material being 100%, the nano-iron powder accounts for 0.5wt% and the micron-shaped spherical titanium powder accounts for 99.5wt%. The nano-iron powder has a particle size of 400nm and a purity of 99.7%. The micron-shaped spherical titanium powder has a particle size of 25μm and a purity of 99.95%.
[0078] The preparation method comprises the following steps:
[0079] Provide an argon gas atmosphere, where the oxygen concentration is ≤100ppm;
[0080] Nano iron powder and micron spherical titanium powder were mixed according to the mass percentages provided in Example 2, and processed in a three-dimensional powder mixer at a speed of 130 rpm for 2 hours to obtain a mixed powder;
[0081] The mixed powder is printed layer by layer using an additive manufacturing process to obtain a titanium alloy material. The process parameters of the additive manufacturing process include: substrate preheating temperature of 200°C, laser power of 100W, scanning speed of 600mm / s, layer thickness of 0.03mm, and scanning spacing of 0.105mm. In the layer-by-layer printing step, the printing path of each layer is rotated 90° clockwise based on the previous layer, and a "striped" mode is adopted.
[0082] Performance test: The obtained titanium alloy material has no β-fleck defects and no TiFe precipitation phase.
[0083] Example 3
[0084] A titanium alloy material that suppresses β-fleck defects by uniformly doping with nano-iron powder. The titanium alloy material uses micron-shaped spherical titanium powder as a substrate, and the nano-iron powder is uniformly distributed inside the substrate. Specifically, based on the total mass of the titanium alloy material being 100%, the nano-iron powder accounts for 1.5wt% and the micron-shaped spherical titanium powder accounts for 98.5wt%. The nano-iron powder has a particle size of 450nm and a purity of 99.7%. The micron-shaped spherical titanium powder has a particle size of 40μm and a purity of 99.95%.
[0085] The preparation method comprises the following steps:
[0086] Provide an argon gas atmosphere, where the oxygen concentration is ≤100ppm;
[0087] Nano iron powder and micron spherical titanium powder were mixed according to the mass percentages provided in Example 3, and processed using a three-dimensional powder mixer at a speed of 100 rpm for 3 hours to obtain a mixed powder;
[0088] The mixed powder is printed layer by layer using an additive manufacturing process to obtain a titanium alloy material. The process parameters of the additive manufacturing process include: substrate preheating temperature of 200°C, laser power of 300W, scanning speed of 800mm / s, layer thickness of 0.04mm, and scanning spacing of 0.105mm. In the layer-by-layer printing step, the printing path of each layer is rotated 90° clockwise based on the previous layer, and a "striped" mode is adopted.
[0089] Performance test: The obtained titanium alloy material has no β-fleck defects and no TiFe precipitation phase.
[0090] Example 4
[0091] A titanium alloy material that suppresses β-fleck defects by uniformly doping with nano-iron powder. The titanium alloy material uses micron-shaped spherical titanium powder as a substrate, and the nano-iron powder is uniformly distributed inside the substrate. Specifically, based on the total mass of the titanium alloy material being 100%, the nano-iron powder accounts for 2wt% and the micron-shaped spherical titanium powder accounts for 98wt%. The nano-iron powder has a particle size of 500nm and a purity of 99.7%. The micron-shaped spherical titanium powder has a particle size of 53μm and a purity of 99.95%.
[0092] The preparation method comprises the following steps:
[0093] Provide an argon gas atmosphere, where the oxygen concentration is ≤100ppm;
[0094] Nano iron powder and micron spherical titanium powder were mixed according to the mass percentages provided in Example 4, and processed in a three-dimensional powder mixer at a speed of 150 rpm for 6 hours to obtain a mixed powder;
[0095] The mixed powder is printed layer by layer using an additive manufacturing process to obtain a titanium alloy material. The process parameters of the additive manufacturing process include: substrate preheating temperature of 200°C, laser power of 400W, scanning speed of 1500mm / s, layer thickness of 0.04mm, and scanning spacing of 0.105mm. In the layer-by-layer printing step, the printing path of each layer is rotated 90° clockwise based on the previous layer, and a "striped" mode is adopted.
[0096] Performance test: The obtained titanium alloy material has no β-fleck defects and no TiFe precipitation phase.
[0097] Comparative Example 1
[0098] A titanium alloy material that suppresses β-fleck defects by uniformly doping with nano-iron powder. The titanium alloy material uses micron-shaped spherical titanium powder as a substrate, and micron-shaped iron powder is uniformly distributed inside the substrate. Specifically, based on the total mass of the titanium alloy material being 100%, the micron-shaped iron powder accounts for 1wt% and the micron-shaped spherical titanium powder accounts for 99wt%. The particle size of the micron-shaped iron powder is 15μm and the purity is 99.7%. The particle size of the micron-shaped spherical titanium powder is 15μm and the purity is 99.95%.
[0099] The preparation method comprises the following steps:
[0100] Provide an argon gas atmosphere, where the oxygen concentration is ≤100ppm;
[0101] Mix micron iron powder and micron spherical titanium powder according to the mass percentages provided in Comparative Example 1, and process them in a three-dimensional powder mixer at a speed of 150 rpm for 3 hours to obtain a mixed powder;
[0102] The mixed powder is printed layer by layer using an additive manufacturing process to obtain a titanium alloy material. The process parameters of the additive manufacturing process include: substrate preheating temperature of 200°C, laser power of 250W, scanning speed of 1000mm / s, layer thickness of 0.04mm, and scanning spacing of 0.105mm. In the layer-by-layer printing step, the printing path of each layer is rotated 90° clockwise based on the previous layer, and a "striped" mode is adopted.
[0103] Performance test: The ultimate tensile strength of the obtained titanium alloy material is 820 MPa, the fracture strain is 11%, and β-fleck defects exist.
[0104] Performance testing and result analysis
[0105] (1) Figure 1 These are SEM images of pure titanium powder, micron iron powder, and the Ti-Fe mixed powder containing nano iron powder obtained in Example 1. It can be seen that the nano iron powder is attached to the titanium powder.
[0106] as well as, Figure 2 This is an EDX image of the Ti-Fe mixed powder containing nano-iron powder obtained in Example 1. It can be seen that the nano-iron powder is evenly distributed on the titanium powder.
[0107] (2) Figure 3 Comparative Example 1 contains Ti-Fe mixed powder containing micron iron powder (such as Figure 3 a) and the Ti-Fe mixed powder containing nano iron powder in Example 1 (such as Figure 3 b) SEM image of the titanium alloy prepared, with arrows indicating β-fleck regions. It can be seen that the Ti-Fe mixed powder containing micronized iron powder in Comparative Example 1 has multiple β-fleck defect regions, while the Ti-Fe mixed powder containing nanometer-sized iron powder in Example 1 has no β-fleck defect regions.
[0108] Figure 4 EBSD analysis of the Ti-Fe mixed powder containing micron iron powder in comparative example 1 and the Ti-Fe mixed powder containing nano iron powder in example 1 shows that the Ti-Fe mixed powder containing nano iron powder in example 1 has a uniform β phase matrix and no TiFe precipitate phase.
[0109] In summary, the embodiments of the present application provide a titanium alloy material that suppresses β-fleck defects by uniformly doping with nano-iron powder. The titanium alloy material uses micron-shaped spherical titanium powder as a substrate, and nano-iron powder is uniformly distributed inside the substrate. Due to the small size and large specific surface area of the nano-iron powder, it quickly dissolves and evenly diffuses into the titanium matrix during the laser powder bed melting process, avoiding the problem of local iron element segregation caused by insufficient diffusion of the micron iron powder. At the same time, the nano-iron powder diffuses quickly and avoids local iron enrichment, ensuring that there is no β-phase enriched area (β-fleck) and brittle TiFe precipitation phase. The high surface activity of the nano-iron powder enhances the wettability of the molten pool, promotes melt flow and pore filling, avoids unfused defects, and is beneficial to improving the density of the product. In addition, it is low in cost and highly practical, providing a solution for the application of high-performance titanium alloys in the field of high-end manufacturing, which is beneficial to the widespread application of titanium alloy materials.
[0110] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.
Claims
1. A titanium alloy material with β-fleck defects suppressed by uniform doping with nano-iron powder, characterized in that: The titanium alloy material uses micron-shaped spherical titanium powder as a base material, and nano-iron powder is evenly distributed inside the base material; wherein, based on the total mass of the titanium alloy material being 100%, the nano-iron powder accounts for 0.5-2.0wt% and the micron-shaped spherical titanium powder accounts for 98-99.5wt%.
2. The titanium alloy material with β-fleck defects suppressed by uniform doping with nano iron powder according to claim 1, characterized in that: The nano iron powder has a particle size of 300-500 nm and a purity of ≥99.5%; and / or, The particle size of the micron spherical titanium powder is 15-53 μm, and the purity is ≥99.9%.
3. The titanium alloy material with suppressed β-fleck defects by uniform doping with nano iron powder according to claim 1, characterized in that: The titanium alloy material includes the following features: (a) Density ≥ 99.98%, no β-fleck defect; (b) The β phase is evenly distributed in the microstructure, and there is no TiFe precipitation phase; (c) Ultimate tensile strength ≥940 MPa, fracture strain ≥17%.
4. A method for preparing a titanium alloy material with suppressed β-fleck defects by uniformly doping with nano-iron powder as claimed in any one of claims 1 to 3, characterized in that: The steps include: In an inert gas atmosphere, nano iron powder and micron spherical titanium powder are uniformly mixed according to mass percentage to obtain a mixed powder; The mixed powder is printed layer by layer using an additive manufacturing process to obtain a titanium alloy material.
5. The method for preparing a titanium alloy material with suppressed β-fleck defects by uniformly doping with nano iron powder according to claim 4, characterized in that: In the step of uniformly mixing the nano iron powder and the micron spherical titanium powder according to mass percentage, a three-dimensional powder mixer is used at a rotation speed of 100 to 150 rpm for 45 minutes to 6 hours.
6. The method for preparing a titanium alloy material with suppressed β-fleck defects by uniformly doping with nano iron powder according to claim 4, characterized in that: The inert gas atmosphere includes at least one of an argon gas atmosphere, a nitrogen gas atmosphere, and a helium gas atmosphere; and, in the inert gas atmosphere, an oxygen concentration is ≤100 ppm.
7. The method for preparing a titanium alloy material with suppressed β-fleck defects by uniformly doping with nano iron powder according to claim 4, characterized in that: The process parameters of the additive manufacturing process include: substrate preheating temperature of 200-220°C, laser power of 100-400W, scanning speed of 600-1500mm / s, layer thickness of 0.03-0.05mm, and scanning spacing of 0.105-0.110mm.
8. The method for preparing a titanium alloy material with suppressed β-fleck defects by uniformly doping with nano iron powder according to claim 4, characterized in that: In the step of layer-by-layer printing, the printing path of each layer is rotated 90° clockwise based on the previous layer, and a "striped" mode is adopted.
9. The method for preparing a titanium alloy material with suppressed β-fleck defects by uniformly doping with nano iron powder according to claim 8, characterized in that: The dimensions of the titanium alloy material are: length 24-26 mm, width 13-15 mm, and thickness 2.5-3 mm.
10. Use of the titanium alloy material according to any one of claims 1 to 3 in the field of biomedicine in which β-fleck defects are suppressed by uniform doping with nano-iron powder.