Method for preparing high-oxygen-content titanium alloy by adopting laser powder bed melting process

Abstract

The invention provides a method for preparing a high-oxygen-content titanium alloy by adopting a laser powder bed melting process, and belongs to the technical field of additive manufacturing titanium alloy preparation. Pure titanium powder and metal oxide powder are subjected to ball-milling dispersion treatment to obtain titanium alloy composite powder; and after the titanium alloy composite powder is subjected to preheating treatment in a vacuum environment, a laser powder bed melting process is adopted for printing forming, and the high-oxygen-content titanium alloy is obtained. On the basis of a laser powder bed melting technology, through reasonable design of powder components and a preparation process in the early stage, various high-oxygen-content titanium alloys (Ti-M-O alloys, and M is Cu, Fe, Ni, Cr, Co or Mn) with excellent comprehensive performance can be prepared, so that the requirements on material performance in industrial production are met.

Description

Technical Field

[0001] This invention belongs to the field of additive manufacturing titanium alloy preparation technology, and particularly relates to a method for preparing high oxygen content titanium alloys using laser powder bed melting process. Background Technology

[0002] Titanium alloys, due to their low density, high specific strength and stiffness, excellent corrosion resistance, and strong thermal stability, have been widely used in key structural components in modern aerospace, transportation, and equipment manufacturing. Laser additive manufacturing technology, as an emerging advanced manufacturing method, possesses advantages such as high design flexibility, short manufacturing cycle, high integration, and rapid cooling rate, significantly shortening the processing and assembly cycle of parts and is considered a revolutionary technology of epoch-making significance. In recent years, additive manufacturing of titanium alloys has developed rapidly and has attracted widespread attention from researchers in various fields. Currently, the comprehensive mechanical properties of additively manufactured titanium alloys have initially approached the level of traditional forged materials. Furthermore, leveraging its laser sintering and rapid cooling process characteristics, it is expected to develop new titanium alloy systems. However, this technology still faces problems such as insufficient mechanical properties and limited strengthening efficiency in practical applications, urgently requiring the exploration of new strategies and methods to solve these problems.

[0003] Carbon, nitrogen, and oxygen are common interstitial elements in titanium alloys, exerting a significant strengthening effect, with their strengthening efficiency being significantly higher than other alloying elements and external reinforcing phases. Among them, oxygen is the most common interstitial element, with a particularly significant strengthening effect. However, according to the design principle of titanium alloys, "Al+10(O+C+2N)+1 / 3Sn+1 / 6Zr<9.0wt.%", the theoretical upper limit of oxygen content in aluminum-containing titanium alloys is only about 0.3wt.%. For aluminum-free titanium alloys, although the oxygen content can be increased to 0.72wt.%, oxygen is prone to segregation at grain boundaries. Increased oxygen content at grain boundaries leads to a significant increase in grain boundary brittleness, resulting in grain boundary cracking. At the same time, oxygen may also agglomerate within the grains, causing premature material failure, thus making it difficult to fully realize its strengthening potential. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a method for preparing high-oxygen-content titanium alloys using laser powder bed melting. This method fully leverages the reinforcing effect of oxygen as an interstitial atom, effectively solving problems such as oxygen segregation at grain boundaries and grain agglomeration in high-oxygen-content titanium alloys.

[0005] To achieve the above objectives, the present invention provides the following technical solution: This invention proposes a method for preparing high-oxygen-content titanium alloys using laser powder bed melting technology, comprising the following steps: Pure titanium powder (TA1) and metal oxide powder (M)x O y Titanium alloy composite powder (TA1+M) was obtained by ball milling dispersion treatment of (where M represents a metallic element, x represents the number of atoms of the metallic element, and y represents the number of atoms of the oxygen element). x O y ); The titanium alloy composite powder was preheated in a vacuum environment and then printed using a laser powder bed melting process to obtain a high oxygen content titanium alloy.

[0006] Further, the preheating treatment is performed at a temperature of 50-100°C for 1-3 hours. Preferably, the preheating treatment is performed at a temperature of 100°C for 2 hours.

[0007] Further, the process parameters of the laser powder bed melting process are as follows: laser power of 160-240W, scanning speed of 600-1400mm / s, scanning line spacing of 100-140μm, powder layer thickness of 30-40μm, and substrate temperature of 45-60℃. Preferably, the process parameters of the laser powder bed melting process are as follows: laser power of 160-200W, scanning speed of 800-1000mm / s, scanning line spacing of 100-140μm, powder layer thickness of 30-40μm, and substrate temperature of 45℃.

[0008] Further, the ball-to-material ratio in the ball milling dispersion treatment is 1:1-5:1, and the dispersion time is 10-40 hours. Preferably, the ball-to-material ratio is 1:1-2:1, and the dispersion time is 16-20 hours.

[0009] Furthermore, the pure titanium powder has a particle size of 15-53 μm, and the oxide powder has a particle size of 200 nm-10 μm.

[0010] Furthermore, the type of oxide powder is determined according to the type of high oxygen-containing titanium alloy ultimately required, including but not limited to ferric oxide (Fe2O3), ferrous oxide (FeO), copper oxide (CuO), nickel oxide (NiO), chromium oxide (Cr2O3), cobalt oxide (CoO), and manganese oxide (MnO).

[0011] Furthermore, the mass ratio of the pure titanium powder to the oxide powder is (98-99):(1-2), for example, the mass ratio of the pure titanium powder to the oxide powder is 98:2 or 99:1.

[0012] Furthermore, the titanium alloy composite powder needs to pass through a 200-400 mesh sieve before preheating treatment, preferably through a 300 mesh sieve.

[0013] This invention also proposes a high-oxygen-content titanium alloy prepared according to the above method, wherein the oxygen content in the high-oxygen-content titanium alloy is 0.3-0.8 wt.%. More specifically, the high-oxygen-content titanium alloy prepared by this invention comprises, by mass percentage: 1-5 wt.% metallic elements, 0.3-0.8 wt.% oxygen elements, and the balance being titanium elements.

[0014] This invention utilizes the characteristics of laser localized sintering and rapid cooling in additive manufacturing technology. By mixing oxides with titanium alloy powder, appropriate β-phase stabilizing elements (such as M=Cu, Fe, Ni, Cr, Co, Mn, etc.) and oxygen can be simultaneously introduced into the titanium matrix, effectively avoiding oxygen segregation at grain boundaries and intragranular agglomeration. Through the synergistic effect between Ti and OM elements, a high oxygen content can be uniformly distributed and stably exist within the grains as interstitial atoms. This distribution enhances the mechanical properties of the material through the interaction between local solutes and dislocations, while also strengthening the interaction between basal / cylindrical and conical surfaces, thereby significantly improving the elongation of the material through mechanisms such as promoting cross-slip. Therefore, using oxide-titanium alloy composite powder and preparing high-oxygen-content titanium alloys through laser powder bed melting is expected to fully leverage the strengthening effect of interstitial elements, thereby significantly improving the comprehensive mechanical properties of titanium alloys.

[0015] Compared with the prior art, the present invention has the following advantages and technical effects: (1) This invention prepares a high-oxygen-content titanium alloy with excellent comprehensive mechanical properties. This invention is based on the characteristics of laser local sintering and rapid cooling in laser powder bed melting technology, using metal oxide M x O y (M = Cu, Fe, Ni, Cr, Co, Mn, etc.) decomposes under laser irradiation, and the released metal element M segregates at the α-Ti grain boundaries, promoting the formation of the β phase, thereby effectively inhibiting the enrichment of oxygen elements at the grain boundaries; at the same time, under the diffusion effect, oxygen elements are mainly distributed inside the α-Ti grains and occupy the interstitial positions of the hexagonal lattice, realizing interstitial solid solution strengthening of the material.

[0016] (2) This invention designs and prepares different types of high oxygen-content titanium alloys with excellent comprehensive properties. This invention, through the rational design of powder composition and preparation process in the early stage, can prepare a variety of high oxygen-containing titanium alloys (Ti-MO alloys, where M is Cu, Fe, Ni, Cr, Co, Mn and other elements) with excellent comprehensive performance, thereby meeting the material performance requirements in industrial production. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a process flow diagram of the laser powder bed melting process used in this invention to prepare high oxygen content titanium alloys; Figure 2 The image shows the morphology of the titanium alloy composite powder obtained after mixing in Example 1 (the left side shows the morphology of the composite powder after mixing, and the right side shows the oxide particles on the surface of a single titanium alloy powder particle). Figure 3 The image shows the interstitial oxygen element in the grain structure of the high oxygen content titanium alloy block obtained in Example 1 (the left side shows the distribution of oxygen atoms in the interstitial titanium atoms under dark field image, and the right side shows the distribution of oxygen atoms in the interstitial titanium atoms under bright field image). Figure 4 The engineering stress-strain curve of the Ti-O-Cu alloy prepared in Example 1; Figure 5 The engineering stress-strain curve of the Ti-O-Fe alloy prepared in Example 2; Figure 6 The engineering stress-strain curve of the Ti-O-Ni alloy prepared in Example 3; Figure 7 The engineering stress-strain curve of the Ti-O-Mn alloy prepared in Example 4; Figure 8 The graph shows a comparison of the mechanical properties of the Ti-O-Cu alloys prepared in Example 1 and Comparative Example 1. Detailed Implementation

[0018] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0019] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0020] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0021] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0022] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0023] This invention provides a method for preparing high-oxygen-content titanium alloys using laser powder bed melting, comprising the following steps: Pure titanium powder (TA1) and oxide powder (M) x O y Titanium alloy composite powder (TA1+M) was obtained by ball milling and dispersion treatment of (where M represents a metallic element). x O y ); After preheating titanium alloy composite powder in a vacuum environment, it is printed using laser powder bed melting process to obtain high oxygen content titanium alloy (Ti-OM alloy for short).

[0024] This invention solves the problems of oxygen segregation and agglomeration in high-oxygen-content titanium alloys through a combined process of powder mixing, vacuum preheating, and laser powder bed melting. Ball milling dispersion ensures uniform mixing of pure titanium powder and metal oxide powder, laying the foundation for uniform element distribution. Vacuum preheating removes moisture and residual gases from the powder, preventing porosity defects during printing. The localized sintering and rapid cooling characteristics of laser powder bed melting promote the decomposition of metal oxides, allowing metal elements (Cu, Fe, etc.) to segregate at the α-Ti grain boundaries to form the β phase, inhibiting oxygen enrichment at grain boundaries. Simultaneously, oxygen is uniformly distributed within the grains as interstitial atoms, achieving interstitial solid solution strengthening.

[0025] In a preferred embodiment of the present invention, the preheating temperature is 50-100°C and the time is 1-3 hours. Preferably, the preheating temperature is 100°C and the time is 2 hours.

[0026] The parameter settings described above in this invention can efficiently remove adsorbed moisture and trace gases from titanium alloy composite powder without altering the powder's physicochemical properties. This parameter range avoids excessively high temperatures that could lead to powder oxidation or adhesion, while ensuring sufficient holding time to guarantee thorough impurity removal, thereby improving the density of subsequently printed parts and reducing defects such as cracking and porosity caused by residual gases.

[0027] In a preferred embodiment of the present invention, the process parameters of the laser powder bed melting process are as follows: laser power of 160-240W, scanning speed of 600-1400mm / s, scanning line spacing of 100-140μm, powder layer thickness of 30-40μm, and substrate temperature of 45-60℃. More preferably, the process parameters of the laser powder bed melting process are as follows: laser power of 160-200W, scanning speed of 800-1000mm / s, scanning line spacing of 100-140μm, powder layer thickness of 30-40μm, and substrate temperature of 45℃.

[0028] The process parameters of the laser powder bed melting process in this invention are optimized based on the "melting-solidification" mechanism of laser powder bed melting. A laser power of 160-240W ensures complete powder melting; a scanning speed of 600-1400mm / s and a scanning line spacing of 100-140μm balance forming efficiency and melt pool continuity; and a powder layer thickness of 30-40μm and a substrate temperature of 45-60℃ reduce interlayer stress. This combination of parameters enables rapid cooling, promotes β-phase formation and uniform oxygen solution, while ensuring the dimensional accuracy and mechanical property stability of the formed parts.

[0029] In a preferred embodiment of the present invention, the type of oxide powder is determined according to the type of high oxygen-content titanium alloy required in the end, including but not limited to ferric oxide (Fe2O3), ferrous oxide (FeO), copper oxide (CuO), nickel oxide (NiO), chromium oxide (Cr2O3), cobalt oxide (CoO), and manganese oxide (MnO). This embodiment of the present invention uses MnO, NiO, CuO, and Fe2O3 as examples to prepare high oxygen-content titanium alloys.

[0030] The core function of the metal oxides in this invention is to "simultaneously provide oxygen and β-phase stabilizing metal elements." These oxides are easily decomposed under laser irradiation, releasing oxygen to achieve interstitial strengthening, while the released metal elements (Fe, Cu, etc.) stabilize the β-phase and inhibit oxygen grain boundary segregation. These oxides were chosen because their decomposition temperature matches the laser melting temperature, and the metal elements have good compatibility with the titanium matrix, enabling the overall alloy performance to be improved through the synergistic effect of Ti-OM.

[0031] In a preferred embodiment of the present invention, the ball-to-material ratio for ball milling dispersion is 1:1-5:1, and the dispersion time is 10-40 hours. Preferably, the ball-to-material ratio is 1:1-2:1, and the dispersion time is 16-20 hours.

[0032] In this invention, ball milling dispersion ensures the uniform dispersion of the two powders. A suitable ball-to-powder ratio provides sufficient impact force to break up powder agglomerates; sufficient dispersion time allows the metal oxide powder to adhere uniformly to the surface of the pure titanium powder, avoiding excessively high local concentrations. This parameter range balances dispersion efficiency and powder integrity, preventing powder breakage due to an excessively large ball-to-powder ratio and uneven dispersion due to an excessively small ratio, thus ensuring the uniform distribution of subsequent alloying elements.

[0033] In a preferred embodiment of the present invention, the particle size of the pure titanium powder is 15-53 μm. This particle size is suitable for the powder spreading and melting requirements of laser powder bed melting. Powder within this particle size range has good flowability, which can ensure the uniformity of the powder layer; at the same time, it is convenient to absorb laser energy to achieve full melting, avoiding incomplete melting due to excessively large particle size, and difficulties in powder spreading or accelerated oxidation due to excessively small particle size, thus ensuring the stability of the printing process and the density of the formed parts.

[0034] In a preferred embodiment of the present invention, the oxide powder has a particle size of 200 nm to 10 μm. The nano- to micron-sized particle size increases the contact area between the oxide and the pure titanium powder, making it easier to disperse evenly during ball milling and avoiding agglomeration. During the subsequent laser melting process, the small-particle oxide can decompose rapidly and uniformly, allowing oxygen and metal elements to diffuse into the titanium matrix simultaneously, avoiding defects caused by excessively high local element concentrations and ensuring the consistency of alloy composition and performance.

[0035] In a preferred embodiment of the present invention, the mass ratio of pure titanium powder to oxide powder is (98-99):(1-2), for example, the mass ratio of pure titanium powder to oxide powder is 98:2 or 99:1.

[0036] The mass ratio of pure titanium powder to oxide powder can be precisely controlled to maintain the final oxygen content within the target range of 0.3-0.8 wt.%, which not only breaks through the oxygen content limitation of traditional titanium alloys and fully utilizes the interstitial strengthening effect, but also ensures that the amount of metal elements added is moderate, avoiding grain boundary cracking due to excessive oxides and insufficient strengthening effect due to insufficient oxides, thus optimizing mechanical properties.

[0037] In a preferred embodiment of the present invention, the titanium alloy composite powder needs to be passed through a 200-400 mesh sieve before preheating treatment.

[0038] For example, in this embodiment of the invention, a method for preparing high oxygen-content titanium alloys using laser powder bed melting (process flow diagram is shown) is provided. Figure 1 ), including the following steps: (1) Pure titanium alloy powder (TA1, particle size 15-53μm) and metal oxide powder (M x O y =Fe2O3, FeO, CuO, NiO, Cr2O3, CoO or MnO, with a particle size of 200nm-10μm), placed in a 5L stainless steel container, with a ball-to-particle ratio of 1:1-5:1, and dispersed using a three-dimensional mixing process for 10-40 hours to obtain titanium alloy composite powder (TA1+M). x O y ); (2) Take out the titanium alloy composite powder after three-dimensional mixing and dispersion, pass it through a 200-400 mesh sieve, and then preheat it in a vacuum oven at 50-100℃ for 1-3 hours. After cooling to room temperature, use a 3D printer to prepare it using laser powder bed melting process. Set the process parameters of laser powder bed melting process as follows: laser power of 160-240W, scanning speed of 600-1400mm / s, scanning line spacing of 100-140μm, powder layer thickness of 30-40μm, and substrate temperature of 45-60℃ to obtain high oxygen content titanium alloy.

[0039] In this embodiment of the invention, the "laser powder bed melting process" is an additive manufacturing process based on the powder bed melting (PBF) principle. It uses a high-energy laser beam to scan and completely melt powder materials (metals) layer by layer, causing them to solidify and accumulate into shape.

[0040] The present invention also proposes a high oxygen content titanium alloy prepared according to the above method, wherein the high oxygen content titanium alloy comprises, by mass percentage: 1-5 wt.% metal elements, 0.3-0.8 wt.% oxygen elements, and the balance being titanium elements.

[0041] The design of this invention, with an oxygen content of 0.3-0.8 wt.% in the high-oxygen titanium alloy, is key to balancing strengthening effect and structural stability. This range is higher than the upper limit of oxygen content in traditional aluminum-containing titanium alloys (approximately 0.3 wt.%), fully utilizing the interstitial strengthening effect of oxygen; while the synergistic effect of metallic elements (Cu, Fe, etc.) avoids grain boundary segregation and agglomeration problems caused by excessive oxygen content. Simultaneously, this combination of oxygen content and metallic elements can improve alloy elongation through mechanisms such as promoting cross-slip, achieving comprehensive optimization of strength and plasticity.

[0042] In this embodiment of the invention, the theoretical calculations only consider the oxygen introduced by the additional metal oxides. However, in reality, the pure titanium powder (TA1) itself already contains a certain amount of oxygen. This is a common phenomenon in all commercial titanium powders; oxygen is the most common and difficult-to-remove interstitial impurity element in titanium. Therefore, the actual oxygen content = background oxygen of the titanium powder + oxygen introduced by the oxides. This makes the actual measured value necessarily higher than the "theoretical value" calculated solely from the oxides.

[0043] In this embodiment of the invention, room temperature refers to "25±2℃".

[0044] All raw materials used in the embodiments of this invention are commercially available. The pure titanium alloy powder (TA1) is purchased from the market (any manufacturer), with a purity of 99.9% and a particle size of 15-53 μm. All metal oxide powders used are commercially available, with a particle size of 2-10 μm.

[0045] The technical solution of the present invention will be further illustrated by the following embodiments.

[0046] Example 1 A method for preparing high-oxygen-content titanium alloys using laser powder bed melting technology includes the following steps: (1) Weigh 980g of pure titanium alloy powder (TA1, with a particle size of 15-53μm) and 20g of metal oxide powder (CuO, with a particle size of 200nm-10μm), place them in a 5L stainless steel container, with a ball-to-material ratio of 2:1, and disperse them for 20h using a three-dimensional mixing process to obtain titanium alloy composite powder; (2) Take out the titanium alloy composite powder after three-dimensional mixing and dispersion, pass it through a 300-mesh sieve, and then preheat it in a vacuum oven at 100°C for 2 hours. After cooling to room temperature, use a 3D printer to prepare it using laser powder bed melting process. The process parameters of laser powder bed melting process are set as follows: laser power is 160W, scanning speed is 800mm / s, scanning line spacing is 100μm, powder layer thickness is 30μm, and substrate temperature is 45°C to obtain a high oxygen content titanium alloy block (Ti-O-Cu alloy).

[0047] The theoretical oxygen content of the Ti-O-Cu alloy is 0.40 wt.%, while the actual oxygen content is 0.60 wt.%.

[0048] Example 2 A method for preparing high-oxygen-content titanium alloys using laser powder bed melting technology includes the following steps: (1) Weigh 980g of pure titanium alloy powder (TA1, with a particle size of 15-53μm) and 20g of metal oxide powder (Fe2O3, with a particle size of 200nm-10μm), place them in a 5L stainless steel container, with a ball-to-material ratio of 1:1, and disperse them for 16h using a three-dimensional mixing process to obtain titanium alloy composite powder; (2) Take out the titanium alloy composite powder after three-dimensional mixing and dispersion, pass it through a 300-mesh sieve, and then preheat it in a vacuum oven at 100°C for 2 hours. After cooling to room temperature, use a 3D printer to prepare it using laser powder bed melting process. The process parameters of laser powder bed melting process are set as follows: laser power is 180W, scanning speed is 1000mm / s, scanning line spacing is 140μm, powder layer thickness is 30μm, and substrate temperature is 45°C to obtain a high oxygen content titanium alloy block (Ti-O-Fe alloy).

[0049] The theoretical oxygen content of the Ti-O-Fe alloy is 0.60 wt.%, while the actual oxygen content is 0.70 wt.%.

[0050] Example 3 A method for preparing high-oxygen-content titanium alloys using laser powder bed melting technology includes the following steps: (1) Weigh 990g of pure titanium alloy powder (TA1, with a particle size of 15-53μm) and 10g of metal oxide powder (NiO, with a particle size of 200nm-10μm), place them in a 5L stainless steel container, with a ball-to-material ratio of 2:1, and disperse them for 18h using a three-dimensional mixing process to obtain titanium alloy composite powder. (2) Take out the titanium alloy composite powder after three-dimensional mixing and dispersion, pass it through a 300-mesh sieve, and then preheat it in a vacuum oven at 100°C for 2 hours. After cooling to room temperature, use a 3D printer to prepare it using laser powder bed melting process. The process parameters of laser powder bed melting process are set as follows: laser power is 200W, scanning speed is 800mm / s, scanning line spacing is 120μm, powder layer thickness is 35μm, and substrate temperature is 45°C to obtain a high oxygen content titanium alloy block (Ti-O-Ni alloy).

[0051] The theoretical oxygen content of the Ti-O-Ni alloy is 0.36 wt.%, while the actual oxygen content is 0.50 wt.%.

[0052] Example 4 A method for preparing high-oxygen-content titanium alloys using laser powder bed melting technology includes the following steps: (1) Weigh 980g of pure titanium alloy powder (TA1, with a particle size of 15-53μm) and 20g of metal oxide powder (MnO, with a particle size of 200nm-10μm), place them in a 5L stainless steel container, with a ball-to-material ratio of 1:1, and disperse them for 20h using a three-dimensional mixing process to obtain titanium alloy composite powder. (2) Take out the titanium alloy composite powder after three-dimensional mixing and dispersion, pass it through a 300-mesh sieve, and then preheat it in a vacuum oven at 100°C for 2 hours. After cooling to room temperature, use a 3D printer to prepare it using laser powder bed melting process. The process parameters of laser powder bed melting process are set as follows: laser power is 180W, scanning speed is 800mm / s, scanning line spacing is 100μm, powder layer thickness is 40μm, and substrate temperature is 45°C to obtain a high oxygen content titanium alloy block (Ti-O-Mn alloy).

[0053] The theoretical oxygen content of the Ti-O-Mn alloy is 0.45 wt.%, while the actual oxygen content is 0.55 wt.%.

[0054] Performance testing The morphology of the titanium alloy composite powder obtained after mixing in Example 1 is shown in the figure. Figure 2 (The left side shows the morphology of the composite powder after mixing, and the right side shows the oxide particles on the surface of a single titanium alloy powder particle.) It can be seen that the oxide particles are uniformly dispersed on the surface of the titanium alloy powder and do not change the sphericity of the titanium alloy powder.

[0055] The characterization diagram of interstitial oxygen element in the high oxygen content titanium alloy bulk obtained in Example 1 is shown in the figure. Figure 3 (The left image shows oxygen atoms distributed in the interstices of titanium atoms under dark field image, and the right image shows oxygen atoms distributed in the interstices of titanium atoms under bright field image.) It can be seen that oxygen atoms are located in the interstitial position of the α phase of titanium alloy.

[0056] The engineering stress-strain curves of the high oxygen-content titanium alloy blocks prepared in Examples 1-4 are shown below. Figure 4-7 As can be seen, the prepared alloy has excellent comprehensive mechanical properties, with a tensile strength of 1100 ~ 1300 MPa and a fracture elongation of 5 ~ 15%.

[0057] Comparative Example 1 Same as Example 1, except that the Ti-O-Cu alloy was prepared by casting. Titanium ingots, copper ingots, and titanium dioxide ingots of the same content were fed in sequence from low melting point to high melting point, and the furnace was shut off and evacuated to 8.0 × 10⁻⁶. -4The pressure is increased to MPa, and then argon gas is introduced for two purges. First, a small current is used to ignite the arc at a distance of 1 cm from the raw material to begin melting. The current is gradually increased until the raw material is liquefied. After 5 minutes, the current is gradually reduced. The arc is extinguished and the material is cooled. After cooling, the material is flipped using a turning rod to prevent the raw material from absorbing oxygen at high temperatures or causing oxidation. After cooling, the material is flipped and the arc is ignited again for melting. Once a liquid is formed, magnetic stirring is activated, with the magnetic stirring current controlled at 10-20 A. Then, the melting current is increased to 350-600 A, and the current is controlled according to the flow of the liquid to prevent low-melting-point components from burning off during the melting process. After ensuring the alloy composition is uniform, the material is placed in a square mold and completely melted into a liquid. It is then cooled and solidified in the furnace to obtain the Ti-O-Cu alloy.

[0058] Performance testing The mechanical properties of the Ti-O-Cu alloys prepared in Example 1 and Comparative Example 1 were tested three times each (i.e., Sample 1, Sample 2, and Sample 3). The test results are shown in [Figure 1]. Figure 8 As can be seen, the mechanical properties of the alloy prepared by the method of Example 1 are significantly better than those of Comparative Example 1.

[0059] Comparative Example 2 Same as Example 1, except that the preheating step is omitted.

[0060] Comparative Example 3 Same as Example 1, except that the process parameters of the laser powder bed melting process are: laser power of 300W, scanning speed of 500mm / s, scanning line spacing of 200μm, powder layer thickness of 15μm, and substrate temperature of 30℃.

[0061] Comparative Example 4 Same as Example 1, except that the mass ratio of pure titanium powder to oxide powder is 93:7.

[0062] Comparative Example 5 Same as Example 2, except that step (1) is different, specifically: 980g of pure titanium alloy powder (TA1, particle size 15-53μm), 20g of metal oxide powder (Fe2O3, particle size 200nm-10μm) and SiO2 powder (particle size 15-53μm) were weighed and placed in a 5L stainless steel container with a ball-to-particle ratio of 2:1. The mixture was dispersed for 20h using a three-dimensional mixing process to obtain titanium alloy composite powder. The remaining steps are consistent with those in Example 2.

[0063] Tests showed that the mechanical properties of Comparative Examples 2-5 were lower than those of Examples 1 or 2. This is because the preheating treatment (50-100℃, 1-3h, vacuum) in Comparative Example 2 mainly removes adsorbed moisture and residual gas from the powder surface, preventing defects such as pores and cracks during laser melting. The overall parameters of Comparative Example 3 were mismatched, making it impossible to achieve rapid cooling and uniform element diffusion, and oxygen elements may segregate or agglomerate. In Comparative Example 4, the proportion of oxides was significantly increased (7%), resulting in oxygen content exceeding the reasonable range. Excessive oxygen content easily leads to oxygen enrichment at grain boundaries, increasing grain boundary brittleness and causing cracking. At the same time, excessive metal element M content may also disrupt the phase balance between α-Ti and β-Ti, affecting the overall performance. In Comparative Example 5, SiO2 may form brittle silicon oxide or silicide phases, disrupting the matrix continuity, failing to achieve the Ti-O-M synergistic effect, and even introducing impurity phases, reducing mechanical properties.

[0064] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing high-oxygen-content titanium alloys using laser powder bed melting technology, characterized in that, Includes the following steps: Titanium alloy composite powder is obtained by ball milling and dispersing pure titanium powder and metal oxide powder. The titanium alloy composite powder was preheated in a vacuum environment and then printed using a laser powder bed melting process to obtain a high oxygen content titanium alloy.

2. The method for preparing high-oxygen-content titanium alloys using laser powder bed melting process according to claim 1, characterized in that, The preheating treatment is performed at a temperature of 50-100℃ for 1-3 hours.

3. The method for preparing high-oxygen-content titanium alloys using laser powder bed melting process according to claim 1, characterized in that, The process parameters for the laser powder bed melting process are as follows: laser power of 160-240W, scanning speed of 600-1400mm / s, scanning line spacing of 100-140μm, powder layer thickness of 30-40μm, and substrate temperature of 45-60℃.

4. The method for preparing high-oxygen-content titanium alloys using laser powder bed melting process according to claim 1, characterized in that, The metal oxide powder includes one or more of the following: ferric oxide, ferrous oxide, copper oxide, nickel oxide, chromium oxide, cobalt oxide, and manganese oxide.

5. The method for preparing high-oxygen-content titanium alloys using laser powder bed melting process according to claim 1, characterized in that, The ball-to-material ratio for the ball milling dispersion treatment is 1:1-5:1, and the dispersion time is 10-40 hours.

6. The method for preparing high-oxygen-content titanium alloys using laser powder bed melting process according to claim 1, characterized in that, The particle size of the pure titanium powder is 15-53 μm.

7. The method for preparing high-oxygen-content titanium alloys using laser powder bed melting process according to claim 1, characterized in that, The oxide powder has a particle size of 200 nm to 10 μm.

8. The method for preparing high-oxygen-content titanium alloys using laser powder bed melting process according to claim 1, characterized in that, The mass ratio of the pure titanium powder to the oxide powder is (98-99):(1-2).

9. The method for preparing high-oxygen-content titanium alloys using laser powder bed melting process according to claim 1, characterized in that, The titanium alloy composite powder needs to be passed through a 200-400 mesh sieve before preheating treatment.

10. A high-oxygen-content titanium alloy prepared by the method according to any one of claims 1-9, characterized in that, The oxygen content in the high oxygen titanium alloy is 0.3-0.8 wt.%.

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