Titanium alloy powder for additive manufacturing and method for producing the same

Abstract

The application discloses a titanium alloy powder for additive manufacturing and a preparation method thereof, and the preparation method comprises the following steps: S1, mixing 95-99 parts of titanium raw material, 0.1-1 parts of carbon nanotubes and 1-5 parts of zirconium powder, and then performing hydrogen absorption treatment to obtain titanium hydride material; S2, mixing the titanium hydride material obtained in the step S1 with 2-10 parts of aluminum powder, 1-5 parts of vanadium powder and 0.01-0.5 parts of rare earth element powder, and then performing high-energy ball milling to obtain titanium hydride powder material; and S3, placing the titanium hydride powder material obtained in the step S2 into a vacuum sintering furnace to perform dehydrogenation treatment, and obtaining titanium hydride-dehydrogenated powder material. The titanium alloy powder prepared by the application has the advantages of high compactness and low oxygen content.

Description

Technical Field

[0001] This application relates to the field of additive manufacturing, and more particularly to a titanium alloy powder for additive manufacturing and a method for preparing the same. Background Technology

[0002] Additive manufacturing (AM), also known as 3D printing, is a manufacturing technology that integrates computer-aided design, materials processing, and forming technologies. Based on digital model files, it uses software and CNC systems to deposit specialized metallic, non-metallic, and medical / biomaterials layer by layer through methods such as extrusion, sintering, melting, photopolymerization, and spraying to create physical objects. Currently, this technology is widely used in aerospace, military, marine, medical / chemical, and new energy fields.

[0003] Titanium and titanium alloys possess low density, high strength, good corrosion resistance, high heat resistance, strong mechanical properties, and excellent biocompatibility, making them the most widely used raw materials in aluminum alloy additive manufacturing (AM). High-quality titanium alloy powder is the foundation of titanium alloy powder additive manufacturing technology. Many powder properties affect the performance of the final AM formed parts, such as appearance quality, chemical composition, particle size and distribution, flowability, density, purity, and hollow powder content. As titanium alloy additive manufacturing technology develops towards larger scale, greater complexity, higher quality, and lower cost, the demand for high-quality titanium alloy powder is becoming increasingly urgent. Titanium alloy additive manufacturing technology and high-performance titanium alloy powder preparation technology will have a broader development prospect. Summary of the Invention

[0004] One object of this application is to provide a titanium alloy powder for additive manufacturing and a method for preparing the same, which has the advantages of high density and low oxygen content.

[0005] To achieve the above objectives, one aspect of this application provides a method for preparing titanium alloy powder for additive manufacturing, comprising the following steps:

[0006] S1, 95-99 parts by weight of titanium raw material, 0.1-1 parts by weight of carbon nanotubes and 1-5 parts by weight of zirconium powder are mixed and subjected to hydrogen absorption treatment to obtain titanium hydride material;

[0007] S2, mix the titanium hydride material obtained in step S1 with 2 to 10 parts by mass of aluminum powder, 1 to 5 parts by mass of vanadium powder and 0.01 to 0.5 parts by mass of rare earth element powder, and then perform high-energy ball milling to obtain titanium hydride powder.

[0008] S3. The titanium hydride powder obtained in step S2 is placed in a vacuum sintering furnace for dehydrogenation treatment to obtain dehydrogenated titanium hydride powder.

[0009] In some embodiments, in step S1, titanium raw materials, carbon nanotubes and zirconium powder are first mixed evenly in a mixing device, and then placed in a hydrogen absorption furnace. Under a temperature of 550 to 800°C and a pressure of 0.04 to 0.05 kPa, hydrogen absorption treatment is carried out for 3 to 6 hours to obtain titanium hydride material.

[0010] In some embodiments, the titanium raw material in step S1 is selected from one or more of the following mixtures: sponge titanium, titanium alloy scrap, titanium chips, and titanium offcuts.

[0011] In some embodiments, the carbon nanotubes in step S1 are multi-walled carbon nanotubes with an average length of 5 to 20 μm.

[0012] In some embodiments, the ball-to-material ratio in step S2 of high-energy ball milling is 4 to 9:1, and the ball milling time is 12 to 24 hours.

[0013] In some embodiments, the rare earth element in step S2 is one or a mixture of cerium (Ce) and yttrium (Y).

[0014] In some embodiments, the temperature of the vacuum sintering furnace in step S3 is 600-900°C, the vacuum degree is less than 1 Pa, and the holding time is 5-10 h.

[0015] In some embodiments, step S3 is followed by step S4, in which the hydrogenated dehydrogenated titanium powder is subjected to secondary ball milling under the protection of high-purity inert gas to obtain ultrafine titanium alloy powder.

[0016] In some embodiments, step S4 involves secondary ball milling under the protection of high-purity argon gas, at a rotation speed of 4000–6000 r / min and a pressure of 500–700 MPa.

[0017] Another aspect of this application provides a titanium alloy powder prepared by the aforementioned preparation method.

[0018] Compared with the prior art, the beneficial effects of this application are as follows: the preparation method provided by this application can realize the reuse of titanium waste, which is conducive to reducing the cost of titanium alloy powder; the preparation method of this application first mixes carbon nanotubes and zirconium powder with titanium raw materials, and then performs hydrogen absorption. The presence of carbon nanotubes has a certain promoting effect on the hydrogenation process. Moreover, as a reinforcing material, carbon nanotubes can effectively reduce the oxygen content of the final product and increase the density of the product. In addition, the addition of zirconium powder and rare earth elements further reduces the oxygen content in the product, and finally obtains titanium alloy powder with low oxygen content and high density. Detailed Implementation

[0019] The present application will be further described below with reference to specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0020] It should be noted that the terms "first," "second," etc., in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0021] The terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0022] This application provides a method for preparing titanium alloy powder for additive manufacturing, comprising the following steps:

[0023] S1, 95-99 parts by mass of titanium raw material, 0.1-1 parts by mass of carbon nanotubes and 1-5 parts by mass of zirconium powder are mixed and then subjected to hydrogen absorption treatment to obtain titanium hydride material;

[0024] S2, mix the titanium hydride material obtained in step S1 with 2 to 10 parts by mass of aluminum powder, 1 to 5 parts by mass of vanadium powder and 0.01 to 0.5 parts by mass of rare earth element powder, and then perform high-energy ball milling to obtain titanium hydride powder.

[0025] S3. The titanium hydride powder obtained in step S2 is placed in a vacuum sintering furnace for dehydrogenation treatment to obtain dehydrogenated titanium hydride powder.

[0026] Step S1 is primarily a hydrogen absorption step, converting titanium into titanium hydride. Step S2 mainly involves pulverizing the embrittled titanium hydride into powder. During the pulverization process, aluminum powder and vanadium powder are added to form the desired titanium alloy in subsequent steps. Step S3 involves dehydrogenation treatment in a vacuum sintering furnace to finally obtain the titanium alloy. In this application, a small amount of carbon nanotubes is added in step S1. As a reinforcing material, carbon nanotubes can enhance the performance of the titanium substrate. Experiments show that adding carbon nanotubes can significantly increase the density of the product and reduce its oxygen content to some extent. Furthermore, carbon nanotubes have excellent physical adsorption capabilities. Adding carbon nanotubes in step S1 allows them to promote the formation of titanium hydride powder during the hydrogenation process through hydrogen adsorption.

[0027] Furthermore, the addition of zirconium powder during the preparation process significantly reduces the oxygen content of the product. Zirconium and titanium are in the same group and have similar chemical properties, allowing for infinite miscibility with the Ti matrix without hindering subsequent sintering steps and affecting density. Secondly, zirconium acts as an oxygen-fixing agent, forming a Ti-Zr-O ordered phase with oxygen on the titanium surface, which helps reduce the oxygen content in the titanium matrix and also strengthens the material, improving its mechanical properties. The addition of rare earth elements also helps reduce the oxygen content in the final product. Due to their internal oxidation properties, the added rare earth elements undergo redox reactions in the matrix, reducing the oxygen content of the titanium alloy powder. Additionally, the addition of rare earth elements refines the alloy particles, facilitating the preparation of high-performance ultrafine titanium alloy powder. The synergistic effect of the internal oxidation of rare earth elements and the oxygen-fixing effect of zirconium significantly reduces the oxygen content in the product. Furthermore, the preparation method provided in this application allows for flexible control of the cerium, yttrium, and zirconium contents, maximizing the absorption of oxygen content from different systems.

[0028] Specifically, in step S1, titanium raw materials, carbon nanotubes and zirconium powder are mixed evenly in a mixing device, and then placed in a hydrogen absorption furnace. Under a temperature of 550-800℃ and a pressure of 0.04-0.05KPa, hydrogen absorption is performed for 3-6 hours to obtain titanium hydride material.

[0029] Furthermore, the titanium raw material in step S1 is selected from one or more of the following mixtures: sponge titanium, titanium alloy scraps, titanium chips, and titanium offcuts.

[0030] The solution provided in this application can use titanium waste as raw material, which helps to reduce the preparation cost of titanium alloy powder. It is worth mentioning that when titanium powder is selected as raw material, the titanium waste needs to be pretreated to remove surface oil and oxide film.

[0031] Furthermore, the carbon nanotubes in step S1 are multi-walled carbon nanotubes with an average length of 5–20 μm.

[0032] Furthermore, the rare earth element in step S2 is one or a mixture of cerium (Ce) and yttrium (Y).

[0033] Furthermore, in step S2, the ball-to-material ratio of the high-energy ball mill is 4–9:1, and the milling time is 12–24 h, to obtain titanium hydride powder with a particle size of 3–10 μm.

[0034] Furthermore, in step S3, the temperature of the vacuum sintering furnace is 600–900℃, the vacuum degree is less than 1 Pa, and the holding time is 5–10 h.

[0035] Furthermore, after step S3, step S4 is also included: under the protection of high-purity inert gas, the hydrogenated dehydrogenated titanium powder is subjected to secondary ball milling to obtain ultrafine titanium alloy powder.

[0036] Specifically, step S4 involves secondary ball milling under the protection of high-purity argon gas, at a rotation speed of 4000–6000 r / min and a pressure of 500–700 MPa.

[0037]

Example 1

[0038] (1) First, 97.5 parts by mass of titanium raw material, 0.5 parts by mass of multi-walled carbon nanotubes and 2 parts by mass of zirconium powder are added to a mixing tank and mixed for 1 hour. After mixing, the mixture is placed in a hydrogen absorption furnace and subjected to hydrogen absorption treatment at a temperature of 680℃ and a pressure of 0.05Kpa for 5 hours to obtain hydride titanium material.

[0039] (2) The titanium hydride material prepared in step (1) is mixed with 5 parts by mass of aluminum powder, 3 parts by mass of vanadium powder and 0.1 parts by mass of yttrium powder, and then subjected to high-energy ball milling with a ball-to-material ratio of 5:1 and a ball milling time of 18h to obtain titanium hydride powder with a particle size of about 3 to 10 μm.

[0040] (3) The hydrogenated titanium powder prepared in step (2) is placed in a vacuum sintering furnace and dehydrogenated under the conditions of 700℃ and vacuum degree less than 1Pa. The temperature is maintained for 7h to obtain hydrogenated dehydrogenated titanium powder with low oxygen content.

[0041] (4) Under the protection of high-purity argon, the product of step (3) is subjected to secondary ball milling at a speed of 6000 r / min and a pressure of 600 MPa for 10 h to obtain high-performance ultrafine titanium alloy powder.

[0042]

Example 2

[0043] The difference between Example 2 and Example 1 is that the yttrium powder in step (2) is replaced with cerium powder.

[0044]

Example 3

[0045] The difference between Example 3 and Example 1 is that 0.1 parts by weight of yttrium powder in step (2) is replaced with 0.1 parts by weight of yttrium powder and 0.1 parts by weight of cerium powder.

[0046]

Example 4

[0047] The difference between Example 4 and Example 3 is that 3 parts by mass of zirconium powder are added in step (1).

[0048] Comparative Example 1

[0049] The difference between Comparative Example 1 and Example 1 is that multi-walled carbon nanotubes are not added in step (1).

[0050] Comparative Example 2

[0051] (1) First, 97.5 parts by mass of titanium raw material and 0.5 parts by mass of multi-walled carbon nanotubes were vacuum sintered at 800℃. The resulting product was ground at a speed of 4500 r / min to obtain carbon nanotube / Ti composite matrix material. Then, 2 parts by mass of zirconium powder were placed in a mixing tank and mixed with carbon nanotube / Ti composite matrix material for 1 h. After mixing, the mixture was placed in a hydrogen absorption furnace and subjected to hydrogen absorption treatment at a temperature of 680℃ and a pressure of 0.05 kPa for 5 h to obtain hydride titanium material.

[0052] (2) The titanium hydride material prepared in step (1) is mixed with 5 parts by mass of aluminum powder, 3 parts by mass of vanadium powder and 0.1 parts by mass of yttrium powder, and then subjected to high-energy ball milling with a ball-to-material ratio of 5:1 and a ball milling time of 18h to obtain titanium hydride powder with a particle size of about 3 to 10 μm.

[0053] (3) The hydrogenated titanium powder prepared in step (2) is placed in a vacuum sintering furnace and dehydrogenated under the conditions of 700℃ and vacuum degree less than 1Pa. The temperature is maintained for 7h to obtain hydrogenated dehydrogenated titanium powder with low oxygen content.

[0054] (4) Under the protection of high-purity argon, the product of step (3) is subjected to secondary ball milling at a speed of 6000 r / min and a pressure of 600 MPa for 10 h to obtain high-performance ultrafine titanium alloy powder.

[0055] Comparative Example 3

[0056] The difference between Comparative Example 3 and Example 1 is that zirconium powder is not added in step (1).

[0057] Comparative Example 4

[0058] The difference between Comparative Example 4 and Example 1 is that yttrium powder is not added in step (2).

[0059] Performance Evaluation

[0060] The titanium alloy powders prepared in each example and comparative example were subjected to elemental analysis using an oxygen, nitrogen, and hydrogen analyzer. The results of oxygen content, nitrogen content, and hydrogen content are shown in the table below. Table 1: Oxygen, nitrogen, and hydrogen content of different titanium alloy powders

[0061] The density of the titanium alloy powder in each embodiment and comparative example was tested using Archimedes' displacement method, and the density was determined according to the formula... (ρ0 is the actual density of the measured sample, g / cm³) 3 ;ρ 理The density was calculated based on the theoretical density of the sample. The calculation results are shown in the table below. Table 2: Density of different ultrafine titanium alloy powders

[0062] Based on the oxygen content data in Table 1 above, it can be seen that the oxygen content of Examples 1-4 of this application is all below 1000 ppm, while Comparative Example 3, which did not add zirconium powder, has a significantly increased oxygen content compared to the other examples. Comparative Example 4, which did not add rare earth elements, has an even higher oxygen content than Comparative Example 3. This shows that the addition of zirconium powder and rare earth elements both have a significant effect on reducing the oxygen content of the product. Furthermore, although two rare earth elements were added in Example 3, and the total content of rare earth elements was higher than in Examples 1, 2, and 4, the oxygen content of the product did not decrease significantly. This indicates that simply increasing the content of rare earth elements cannot significantly reduce the oxygen content. Compared to Example 3, Example 4, by simply increasing the amount of zirconium powder added, showed a significant decrease in oxygen content, indicating a certain synergistic effect between zirconium powder and rare earth elements, which can synergistically reduce the oxygen content of titanium alloy powder. In addition, the oxygen content of Comparative Examples 1 and 2 is higher than that of Examples 1-4, indicating that the addition of carbon nanotubes also has a certain promoting effect on reducing the impurity content of the product.

[0063] Based on the density data in Table 2 above, it can be seen that the density of Examples 1-4 of this application all reached over 99%, while the density of Comparative Example 1, which did not add carbon nanotubes during the preparation process, was only 85.8%. This shows that the addition of carbon nanotubes has a significant effect on improving the density of the product. Although Comparative Example 2 also used carbon nanotubes, the density of the product in Comparative Example 2 was lower than that of Examples 1-4. This is because the process of Comparative Example 2 was slightly different from that of the other examples, indicating that the process conditions for carbon nanotube composites also affect the density of the final product. In addition, Comparative Example 4, due to the absence of rare earth elements, also had a relatively low product density, showing that the addition of rare earth elements is also beneficial to improving the density of the product.

[0064] The basic principles, main features, and advantages of this application have been described above. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of this application. Various changes and modifications can be made to this application without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by this application is defined by the appended claims and their equivalents.

Claims

1. A method for preparing titanium alloy powder for additive manufacturing, characterized in that, Includes the following steps: S1. Mix 95-99 parts by weight of titanium raw material, 0.1-1 parts by weight of multi-walled carbon nanotubes and 1-5 parts by weight of zirconium powder evenly in a mixing device, and then put it into a hydrogen absorption furnace. Under a temperature of 550-800℃ and a pressure of 0.04-0.05KPa, treat with hydrogen absorption for 3-6 hours to obtain titanium hydride material. S2, the titanium hydride material obtained in step S1 is mixed with 2-10 parts by mass of aluminum powder, 1-5 parts by mass of vanadium powder and 0.01-0.5 parts by mass of rare earth element powder, and then subjected to high-energy ball milling. The ball-to-material ratio of the high-energy ball milling is 4-9:1 and the ball milling time is 12-24 hours to obtain titanium hydride powder. The rare earth element is one or a mixture of cerium (Ce) and yttrium (Y). S3, the titanium hydride powder obtained in step S2 is placed in a vacuum sintering furnace for dehydrogenation treatment. The temperature of the vacuum sintering furnace is 600~900℃, the vacuum degree is less than 1Pa, and the temperature is maintained for 5~10h to obtain dehydrogenated titanium hydride powder. S4. Under the protection of high-purity argon gas, the hydrogenated dehydrogenated titanium powder is subjected to secondary ball milling at a rotation speed of 4000~6000 r / min and a pressure of 500~700 MPa to obtain ultrafine titanium alloy powder.

2. The preparation method according to claim 1, characterized in that, The titanium raw material in step S1 is selected from one or more of the following mixtures: sponge titanium, titanium alloy scraps, titanium chips, and titanium offcuts.

3. The preparation method according to claim 1, characterized in that, The average length of the multi-walled carbon nanotubes in step S1 is 5~20 μm.

4. A titanium alloy powder prepared by any one of the preparation methods described in claims 1-3.

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