Alloy material and preparation method therefor

Abstract

The present application provides an alloy material. The surface of the alloy material is provided with a nitrided layer. A thickness of a region of the nitrided layer in which the atomic percentage of nitrogen is greater than or equal to 1 at% is 1-20 μm. In addition, the mass fraction of nitrogen in the nitrided layer in the alloy material is greater than or equal to 0.1 wt%, and less than or equal to 0.5 wt%. The alloy material has excellent mechanical properties.

Description

An alloy material and its preparation method

[0001] This application claims priority to Chinese Patent Application No. 202410999373.8, filed on July 23, 2024, entitled "An Alloy Material and a Method for Preparing the Same", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of metallurgical technology, and in particular to an alloy material and its preparation method. Background Technology

[0003] High-strength titanium (Ti) alloys, with their excellent comprehensive mechanical properties, are widely used in aerospace, biomedicine, and other fields with stringent material performance requirements. In recent years, novel β-titanium alloys and titanium-based composite materials, among other new high-strength alloy powder materials, have been developed, further enhancing the performance of titanium alloys. With the increasing pursuit of thinner and lighter designs in end-device electronic devices, the industry has begun to pay close attention to the application of titanium alloys in these devices. Furthermore, 3D printing technology also requires titanium alloy powder raw materials with good mechanical properties.

[0004] Currently, there are several main approaches to improving the mechanical properties of titanium alloys.

[0005] 1. By mixing different dissimilar titanium alloy powders and controlling the microstructure through sintering, heat treatment, and processing, a heterogeneous structure of the titanium alloy can be achieved, improving its strength and plasticity. However, this approach results in an excessive amount of elements in the titanium alloy, potentially causing elemental segregation or clustering, which could affect the uniformity of the titanium alloy's mechanical properties.

[0006] 2. Non-metallic particles are coated onto titanium metal powder using ball milling to obtain titanium alloy composite powder. This method can refine the microstructure of the titanium alloy and improve its strength. However, the ball milling process easily introduces a large number of impurities, and the yield of titanium alloy composite powder using this method is low, with high energy consumption.

[0007] 3. Redesign the composition of the titanium alloy, adjust the ratio of the main elements, and prepare a new titanium alloy using a gas atomization powder preparation process. Redesigning the composition is complex, and the low yield of gas atomization powder preparation results in a higher cost for the new titanium alloy. Summary of the Invention

[0008] This application provides an alloy material and a method for preparing the same. The alloy material has good mechanical properties, and the method is simple, easy to implement, and low in cost.

[0009] In a first aspect, an alloy material is provided, the surface of which has a nitrided layer, wherein the thickness of a region in the nitrided layer with a nitrogen atomic percentage ≥1 at.% is 1 μm-20 μm; and the mass fraction of nitrogen in the nitrided layer in the alloy material is ≥0.1 wt.% and ≤0.5 wt.%. The region in the nitrided layer with a nitrogen atomic percentage ≥1 at.% can be referred to as a nitrogen-enriched region. Exemplarily, the alloy material is any one of a titanium-based alloy, an iron-based alloy, an aluminum-based alloy, or a copper-based alloy. The particle size of the alloy material is 5 μm to 150 μm. Furthermore, the alloy material can be an alloy powder, and the particles of the alloy material can be regular or irregular shapes such as spheres, cylinders, squares, and cones.

[0010] The alloy material has good mechanical properties, with an average yield strength of over 1400 MPa, a tensile strength of around 1500 MPa, and a fracture elongation of 6-8%.

[0011] This alloy material can be used as a raw material for 3D printing, and the resulting product has the same or similar nitrogen content as the alloy material. Furthermore, compared to doping nitrogen into the raw material during the 3D printing process, 3D printed products using this alloy material as a raw material have fewer defects and a more uniform distribution of nitrogen and oxygen.

[0012] In a second aspect, a method for preparing the alloy material provided in the first aspect is provided, the method comprising: heating the alloy raw material to a preset temperature and holding it at that temperature for a preset time in a gas atmosphere containing 5-100 vol.% nitrogen, thereby doping the alloy raw material with nitrogen to obtain the alloy material.

[0013] This method involves calcining the alloy raw material in a nitrogen-containing gas atmosphere, which introduces nitrogen into the raw material. The introduced nitrogen forms a nitrided layer, resulting in an alloy material with superior mechanical properties compared to the raw material. For example, the tensile strength of the alloy material is increased by 60% compared to the raw material. This method is simple and easy to implement, meaning that the mechanical properties of materials can be improved easily and readily.

[0014] In one possible implementation, under a gaseous atmosphere with a nitrogen content of 5-100 vol.%, the alloy raw material is heated to a preset temperature and held at that temperature for a preset time to dope nitrogen into the alloy raw material, thereby obtaining the alloy material. This includes: heating the alloy raw material to a first target temperature at a first heating rate under a gaseous atmosphere; heating the alloy raw material from the first target temperature to a second target temperature at a second heating rate under a gaseous atmosphere; wherein the second heating rate is less than the first heating rate, and the second target temperature is greater than the first target temperature; and holding the alloy raw material at the second target temperature for a preset time under a gaseous atmosphere to dope nitrogen into the alloy raw material, thereby obtaining the alloy material. The first heating rate is 5-15 °C / min, the first target temperature is 520 °C-570 °C, the second heating rate is 1-2 °C / min, the second target temperature is 570-600 °C / min, and the preset time is 20-100 min.

[0015] In this implementation, the alloy raw materials are calcined by segmented heating, which can improve the uniformity of nitrogen enrichment in the nitrided layer or the surface of the alloy material, thereby further improving the mechanical properties of the alloy material.

[0016] In one possible implementation, the alloy raw material is heated to a preset temperature and held for a preset time in a gas atmosphere with a nitrogen content of 5-100 vol.% to dope nitrogen into the alloy raw material, thereby obtaining the alloy material. This includes heating the alloy raw material to 500-800°C at a heating rate of 5-15°C / min in a gas atmosphere and holding for 20-120 min to dope nitrogen into the alloy raw material, thereby obtaining the alloy material.

[0017] In this implementation method, the alloy material can be directly heated to the corresponding temperature to achieve the calcination of the alloy raw material, which further simplifies the method and improves the ease of operation.

[0018] In one possible implementation, the alloy raw material is heated to a preset temperature and held at that temperature for a preset time in a gas atmosphere containing 5-100 vol.% nitrogen to dope nitrogen into the alloy raw material, thereby obtaining the alloy material. This includes: placing the alloy raw material in the furnace chamber of a vacuum heat treatment furnace; introducing a gas containing 5-100 vol.% nitrogen into the furnace chamber to maintain the furnace chamber in a gas atmosphere and to maintain the furnace chamber under positive pressure; heating the temperature of the furnace chamber to the preset temperature and holding it at that temperature for a preset time; at the end of the holding period, cooling the furnace to 200-300°C, and then opening the furnace and cooling it to room temperature.

[0019] This method allows for the preparation of alloy materials using a vacuum heat treatment furnace, improving preparation efficiency and success rate.

[0020] In one possible implementation, the alloying material is any one of titanium, iron, aluminum, copper, titanium-based alloys, iron-based alloys, aluminum-based alloys, and copper-based alloys.

[0021] This method can increase the mechanical properties of various metals or alloys through calcination in a nitrogen-containing atmosphere, and has wide applicability.

[0022] In one possible implementation, the particle size of the alloy raw material is 5 μm to 150 μm.

[0023] This method is applicable to alloy raw materials with a particle size of 5μm to 150μm. In other words, this method can increase the mechanical properties of small-particle-size raw materials and their processed products through calcination in a nitrogen-containing atmosphere, and it can also increase the mechanical properties of large-particle-size raw materials and their processed products through calcination in a nitrogen-containing atmosphere, thus having wide applicability.

[0024] Thirdly, an electronic device is provided, wherein one or more components of the electronic device are made of the alloy material provided in the first aspect.

[0025] In one possible implementation, the component is prepared by 3D printing using the alloy material provided in the first aspect as raw material.

[0026] The third beneficial effect can be referred to the introduction of the first beneficial effect above, and will not be repeated here. Attached Figure Description

[0027] Figure 1 is a schematic diagram of an alloy preparation method provided in an embodiment of this application;

[0028] Figure 2A is a scanning electron microscope (SEM) image of an alloy raw material used in an embodiment of this application;

[0029] Figure 2B is a SEM image of an alloy material prepared according to an embodiment of this application;

[0030] Figure 3 is a flowchart of an alloy preparation method provided in an embodiment of this application;

[0031] Figure 4 is a room temperature tensile stress-strain curve of the alloy material prepared in the embodiments of this application. Detailed Implementation

[0032] The solutions provided in the embodiments of this application will now be described with reference to the accompanying drawings. In the embodiments of this application, "multiple" refers to two or more objects, and "various types" refers to two or more types. Terms such as "first," "second," etc., are only used to distinguish similar objects and are not necessarily used to describe a specific order or number of objects.

[0033] To facilitate understanding of the solutions provided in the embodiments of this application, the technical terms that may be involved in the embodiments of this application will be introduced first.

[0034] Titanium alloy powder: It is a material made into powder form from titanium-based alloys with high specific strength, excellent heat resistance and corrosion resistance using advanced powder making technology. It can be used in 3D printing (additive manufacturing) and traditional metal processing fields, and provides ideal metal powder raw materials for industries with stringent material performance requirements such as aerospace and biomedicine.

[0035] Terminal electronic devices, such as smartphones, foldable phones, tablets, laptops, and smart wearable devices (e.g., smartwatches), require materials with high strength, high rigidity, light weight, drop resistance, and bending resistance. Titanium alloys, with their high strength and low density, have attracted industry attention. However, the yield strength, tensile strength, and elongation at break of current titanium alloys do not yet meet the requirements of terminal electronic devices.

[0036] This application provides an alloy material with a nitrided layer on its surface, wherein the thickness of the nitrogen (N) enriched region in the nitrided layer is 1 μm-20 μm. The nitrogen-rich region is a region where the atomic percentage of nitrogen is ≥1 at.%, where at.% represents atomic percentage. In one example, the thickness of the nitrogen-rich region in the nitrided layer is 1 μm. In another example, the thickness of the nitrogen-rich region in the nitrided layer is 2 μm. In another example, the thickness of the nitrogen-rich region in the nitrided layer is 3 μm. In another example, the thickness of the nitrogen-rich region in the nitrided layer is 5 μm. In another example, the thickness of the nitrogen-rich region in the nitrided layer is 10 μm. In another example, the thickness of the nitrogen-rich region in the nitrided layer is 13 μm. In another example, the thickness of the nitrogen-rich region in the nitrided layer is 17 μm. In another example, the thickness of the nitrogen-rich region in the nitrided layer is 20 μm.

[0037] The nitrogen content in the nitriding layer is ≥0.1 wt.% and ≤0.5 wt.% of the alloy material. In one example, the nitrogen content in the nitriding layer is 0.2 wt.%. In another example, the nitrogen content in the nitriding layer is 0.3 wt.%. In yet another example, the nitrogen content in the nitriding layer is 0.4 wt.%. Here, wt.% represents a mass percentage.

[0038] In some embodiments, the alloy material can be a powder material with a particle size of 5 μm to 150 μm. In one example, the particle size of the alloy material is 5 μm. In one example, the particle size of the alloy material is 7 μm. In one example, the particle size of the alloy material is 13 μm. In one example, the particle size of the alloy material is 18 μm. In one example, the particle size of the alloy material is 22 μm. In one example, the particle size of the alloy material is 25 μm. In one example, the particle size of the alloy material is 30 μm. In one example, the particle size of the alloy material is 36 μm. In one example, the particle size of the alloy material is 47 μm. In one example, the particle size of the alloy material is 52 μm. In one example, the particle size of the alloy material is 63 μm. In one example, the particle size of the alloy material is 76 μm. In one example, the particle size of the alloy material is 89 μm. In one example, the particle size of the alloy material is 94 μm. In one example, the particle size of the alloy material is 103 μm. In one example, the particle size of the alloy material is 115 μm. In one example, the particle size of the alloy material is 124 μm. In another example, the particle size of the alloy material is 136 μm. In another example, the particle size of the alloy material is 141 μm. In yet another example, the particle size of the alloy material is 150 μm.

[0039] In some embodiments, the alloy material may be spherical, square, triangular, cylindrical, or other regular or irregular shaped powder or particles.

[0040] In some embodiments, the alloy material is a titanium-based alloy, i.e., a titanium alloy. This alloy material has an average yield strength exceeding 1400 MPa, a tensile strength of approximately 1500 MPa, and an elongation at break of 6-8%, meeting the requirements of terminal electronic devices. This alloy material can be used as a raw material for 3D printing. That is, 3D printing can be used to process this alloy material to obtain products. The nitrogen content in the product and the alloy material is the same or close, indicating that the alloy material has high stability. Furthermore, compared to doping nitrogen into the raw material during 3D printing, 3D printed products using this alloy material as a raw material have fewer defects and a more uniform distribution of nitrogen and oxygen.

[0041] In some embodiments, the alloy material is an iron-based alloy.

[0042] In some embodiments, the alloy material is an aluminum-based alloy.

[0043] In some embodiments, the alloy material is a copper-based alloy.

[0044] The composition and properties of the alloy material provided in the embodiments of this application have been described above. Next, the method for preparing this alloy material will be described.

[0045] As shown in Figure 1, the overall process of this method is as follows: Obtain the alloy raw material and place it in an atmosphere filled with a nitrogen gas containing 5-100 vol.% nitrogen. While the alloy raw material is in this atmosphere, heat it to a preset temperature and hold it for a preset time for calcination, thereby doping the alloy raw material with nitrogen to obtain the alloy material. The calcination process forms a nitrided layer covering the alloy raw material, where the nitrogen atomic percentage is ≥1 at.%. The thickness of the nitrided layer in this region is 1 μm-20 μm. Calcination, by doping the alloy raw material with nitrogen, significantly improves the average yield strength, tensile strength, and elongation at break. In other words, compared to the original alloy raw material, the alloy material obtained by this method has higher average yield strength, tensile strength, and elongation at break. vol.% represents volume percentage.

[0046] In some embodiments, the alloy raw material can be titanium metal, i.e., elemental titanium. In some embodiments, the alloy raw material can be a titanium-based alloy, such as Ti-6Al-4V.

[0047] In some embodiments, the alloying raw material can be ferrous metal, i.e., elemental iron. In some embodiments, the alloying raw material can be an iron-based alloy, such as steel.

[0048] In some embodiments, the alloy raw material can be aluminum metal, i.e., elemental aluminum. In some embodiments, the alloy raw material can be an aluminum-based alloy.

[0049] In some embodiments, the alloy raw material may be copper metal, i.e., elemental copper. In some embodiments, the alloy raw material may be a copper-based alloy.

[0050] In some embodiments, the alloy raw material is a powder with a particle size of 5 μm to 150 μm. In one example, the particle size of the alloy raw material is 5 μm. In one example, the particle size of the alloy raw material is 7 μm. In one example, the particle size of the alloy raw material is 13 μm. In one example, the particle size of the alloy raw material is 18 μm. In one example, the particle size of the alloy raw material is 22 μm. In one example, the particle size of the alloy raw material is 25 μm. In one example, the particle size of the alloy raw material is 30 μm. In one example, the particle size of the alloy raw material is 36 μm. In one example, the particle size of the alloy raw material is 47 μm. In one example, the particle size of the alloy raw material is 52 μm. In one example, the particle size of the alloy raw material is 63 μm. In one example, the particle size of the alloy raw material is 76 μm. In one example, the particle size of the alloy raw material is 89 μm. In one example, the particle size of the alloy raw material is 94 μm. In one example, the particle size of the alloy raw material is 103 μm. In one example, the particle size of the alloy raw material is 115 μm. In another example, the particle size of the alloy raw material is 124 μm. In another example, the particle size of the alloy raw material is 136 μm. In another example, the particle size of the alloy raw material is 141 μm. In another example, the particle size of the alloy raw material is 150 μm.

[0051] In some embodiments, the alloy raw material may be spherical, square, triangular, cylindrical, or other regular or irregular shaped powders or particles.

[0052] A gas with a nitrogen content of 5-100 vol.% refers to a mixture of nitrogen and other gases, wherein the volume fraction of nitrogen in the mixture is 5-100 vol.%. In some embodiments, the other gas may be an inert gas, such as any combination of one or more of helium (He), neon (Ne), argon (Ar), krypton (Kr), and xenon (Xe). In some embodiments, the other gas may be oxygen (O2), carbon dioxide (CO2), or other gases.

[0053] In some embodiments, a gas with a nitrogen content of 5-100 vol.% specifically refers to a gas with a nitrogen content of 5 vol.%. In some embodiments, a gas with a nitrogen content of 5-100 vol.% specifically refers to a gas with a nitrogen content of 10 vol.%. In some embodiments, a gas with a nitrogen content of 5-100 vol.% specifically refers to a gas with a nitrogen content of 12 vol.%. In some embodiments, a gas with a nitrogen content of 5-100 vol.% specifically refers to a gas with a nitrogen content of 18 vol.%. In some embodiments, a gas with a nitrogen content of 5-100 vol.% specifically refers to a gas with a nitrogen content of 23 vol.%. In some embodiments, a gas with a nitrogen content of 5-100 vol.% specifically refers to a gas with a nitrogen content of 30 vol.%. In some embodiments, a gas with a nitrogen content of 5-100 vol.% specifically refers to a gas with a nitrogen content of 41 vol.%. In some embodiments, a gas with a nitrogen content of 5-100 vol.% specifically refers to a gas with a nitrogen content of 50 vol.%. In some embodiments, a gas with a nitrogen content of 5-100 vol.% specifically refers to a gas with a nitrogen content of 62 vol.%. In some embodiments, a gas with a nitrogen content of 5-100 vol.% specifically refers to a gas with a nitrogen content of 73 vol.%. In some embodiments, a gas with a nitrogen content of 5-100 vol.% specifically refers to a gas with a nitrogen content of 80 vol.%. In some embodiments, a gas with a nitrogen content of 5-100 vol.% specifically refers to a gas with a nitrogen content of 89 vol.%. In some embodiments, a gas with a nitrogen content of 5-100 vol.% specifically refers to a gas with a nitrogen content of 96 vol.%. In some embodiments, a gas with a nitrogen content of 5-100 vol.% specifically refers to a gas with a nitrogen content of 100 vol.%, i.e., a pure nitrogen atmosphere.

[0054] In some embodiments, the method for preparing the alloy material includes: heating the alloy raw material to a first target temperature at a first heating rate in a gas atmosphere with a nitrogen content of 5-100 vol.%; then, heating the alloy raw material from the first target temperature to a second target temperature at a second heating rate in the same gas atmosphere; wherein the second heating rate is less than the first heating rate, and the second target temperature is greater than the first target temperature; and holding the alloy raw material at the second target temperature for a preset time in the same gas atmosphere to dope nitrogen into the alloy raw material, thereby obtaining the alloy material.

[0055] In one example of this embodiment, the first heating rate is 5-15℃ / min, the first target temperature is 520℃-570℃, the second heating rate is 1-2℃ / min, the second target temperature is 570-600℃ / min, and the preset duration is 20-10min. In one specific implementation of this example, the first heating rate is 5℃ / min. In another specific implementation of this example, the first heating rate is 8℃ / min. In yet another specific implementation of this example, the first heating rate is 10℃ / min. In yet another specific implementation of this example, the first heating rate is 13℃ / min. In yet another specific implementation of this example, the first heating rate is 15℃ / min. In yet another specific implementation of this example, the first target temperature is 520℃. In yet another specific implementation of this example, the first target temperature is 528℃. In yet another specific implementation of this example, the first target temperature is 535℃. In another specific implementation of this example, the first target temperature is 542°C. In another specific implementation of this example, the first target temperature is 550°C. In another specific implementation of this example, the first target temperature is 561°C. In another specific implementation of this example, the first target temperature is 568°C. In another specific implementation of this example, the first target temperature is 570°C. In another specific implementation of this example, the second heating rate is 1°C / min. In another specific implementation of this example, the second heating rate is 1.5°C / min. In another specific implementation of this example, the second heating rate is 1.8°C / min. In another specific implementation of this example, the second heating rate is 2°C / min. In another specific implementation of this example, the second target temperature is 570°C. In another specific implementation of this example, the second target temperature is 571°C. In another specific implementation of this example, the second target temperature is 575°C. In another specific implementation of this example, the second target temperature is 580℃. In another specific implementation of this example, the second target temperature is 586℃. In another specific implementation of this example, the second target temperature is 590℃. In another specific implementation of this example, the second target temperature is 593℃. In another specific implementation of this example, the second target temperature is 598℃. In another specific implementation of this example, the second target temperature is 600℃. In another specific implementation of this example, the preset duration is 20 minutes. In another specific implementation of this example, the preset duration is 30 minutes. In another specific implementation of this example, the preset duration is 40 minutes.In another specific implementation of this example, the preset duration is 50 minutes. In another specific implementation of this example, the preset duration is 60 minutes. In another specific implementation of this example, the preset duration is 70 minutes. In another specific implementation of this example, the preset duration is 80 minutes. In another specific implementation of this example, the preset duration is 90 minutes. In another specific implementation of this example, the preset duration is 100 minutes.

[0056] In some embodiments, the method for preparing the alloy material includes: heating the alloy raw material to 500-800°C at a heating rate of 5-15°C / min in a gas atmosphere with a nitrogen content of 5-100 vol.%, and holding at that temperature for 20-120 min, to dope the alloy raw material with nitrogen to obtain the alloy material. In one example of this embodiment, the heating rate is 5°C / min. In another example of this embodiment, the heating rate is 8°C / min. In one example of this embodiment, the heating rate is 10°C / min. In one example of this embodiment, the heating rate is 12°C / min. In one example of this embodiment, the heating rate is 15°C / min. In one example of this embodiment, the alloy raw material is heated to 500°C. In one example of this embodiment, the alloy raw material is heated to 550°C. In one example of this embodiment, the alloy raw material is heated to 580°C. In one example of this embodiment, the alloy raw material is heated to 600°C. In one example of this embodiment, the alloy raw material is heated to 660°C. In one example of this embodiment, the alloy raw material is heated to 700°C. In another example of this embodiment, the alloy raw material is heated to 760°C. In yet another example of this embodiment, the alloy raw material is heated to 800°C.

[0057] In some embodiments, the alloy material can be prepared in a vacuum heat treatment furnace. Specifically, the alloy raw material is placed in the furnace chamber of the vacuum heat treatment furnace; then, a nitrogen gas with a nitrogen content of 5-100 vol.% is introduced into the furnace chamber to maintain the furnace chamber under the gas atmosphere and to maintain the furnace chamber under positive pressure; subsequently, the temperature of the furnace chamber is heated to the preset temperature and held at that temperature for the preset duration; at the end of the holding period, the furnace is cooled to 200-300°C, and then the furnace is opened and cooled to room temperature. In one example, the furnace is opened after cooling to 200°C. In another example, the furnace is opened after cooling to 230°C. In another example, the furnace is opened after cooling to 250°C. In another example, the furnace is opened after cooling to 270°C. In another example, the furnace is opened after cooling to 300°C.

[0058] Next, in a specific embodiment, we will illustrate the implementation of this method with examples.

[0059] Example 1

[0060] Titanium-based alloy spherical powder with the chemical formula Ti-6Al-4V was used as the alloying raw material, and the particle size range of the spherical powder was 25–63 μm. The field-view morphology, single powder spheres, and particle size distribution of the alloying raw material are shown in Figure 2A. Among them, Figure 2A is the SEM image of the alloying raw material.

[0061] In Example 1, a vacuum heat treatment furnace was used as the preparation equipment, wherein the furnace volume was 160L and the alloy raw material being processed was 2 kg. As shown in Figure 3, the preparation method includes the following steps.

[0062] 11. Load the alloy material into the crucible. For example, the crucible is a 304 stainless steel tray or a ceramic tray. Multiple crucibles may be used; the alloy material is loaded into multiple crucibles.

[0063] 12. Vibrate and level the material, then place the crucible inside the furnace. Mechanical vibration is used to ensure the alloy material is evenly spread throughout the crucible. For example, the thickness of the leveled alloy material is less than 10 mm. In one example, the thickness is 6-10 mm.

[0064] 13. Evacuate the furnace chamber of the vacuum heat treatment furnace, then fill it with nitrogen (99.999% purity), and purge the furnace chamber three times.

[0065] 14. Continuously introduce nitrogen gas into the furnace to maintain positive pressure and replenish the nitrogen required for calcination. The nitrogen gas flow rate is 3-4 L / min, and the positive pressure in the furnace is maintained at 0.06-0.1 MPa.

[0066] Then, calcination is carried out. During calcination, nitrogen gas is continuously introduced into the furnace to maintain positive pressure and replenish the nitrogen required for calcination. The nitrogen gas flow rate is 3-4 L / min, maintaining a positive pressure of 0.06-0.1 MPa in the furnace. Calcination includes the following steps.

[0067] 15. Starting from room temperature, heat the temperature inside the furnace to 560℃, with a heating rate of 10℃ / min.

[0068] 16. When the temperature inside the furnace reaches 560℃, raise the temperature inside the furnace to 575℃ at a heating rate of 1.5℃ / min. Hold at 575℃ for 50 minutes.

[0069] 17. After the heat preservation is completed, the furnace is cooled to 300℃. The time required for the furnace to cool to 300℃ is approximately 4 hours.

[0070] 18. After the furnace cools to 300°C, open the furnace and remove the crucible.

[0071] 19. Air cool the crucible.

[0072] 110. After the crucible temperature is cooled to room temperature, the alloy materials in multiple crucibles are mechanically mixed to obtain the final alloy material.

[0073] The field-view morphology, single powder spheres, and particle size distribution of the alloy material prepared in Example 1 are shown in Figure 2B. Figure 2B is the SEM image of the alloy material. From Figures 2A and 2B, it can be seen that there is no significant difference in appearance between the Ti-6Al-4V powder before and after calcination; that is, there is no significant difference in appearance between the alloy raw material and the alloy material prepared from it.

[0074] The nitrogen content in the alloy material prepared in Example 1 was found to be 0.19 wt.%, and the surface of the alloy material was coated with a nitriding layer. The thickness of the nitrogen-enriched region in the nitriding layer ranged from 1 μm to 20 μm. In other words, the thickness of the nitrogen-enriched region in each powder of the alloy material was distributed within the range of 1 μm to 20 μm. Specifically, the thinnest nitrogen-enriched region was 1 μm in the powder with the thinnest nitrogen-enriched region, and the thickest nitrogen-enriched region was 20 μm in the powder with the thickest nitrogen-enriched region.

[0075] In addition, the oxygen content in the alloy material prepared in Example 1 was 0.17 wt.%.

[0076] Using laser melting 3D printing technology, multiple sets of tensile specimens were formed using the alloy material prepared in Example 1 as the printing material. Tensile tests were then conducted, yielding stress-strain curves and related mechanical properties as shown in Figure 4. The average yield strength of these tensile specimens was 1415 MPa, the tensile strength was 1482 MPa, and the elongation at break was 7.13%. Compared to the product obtained by 3D printing using the alloy material (Ti-6Al-4V) used in Example 1, this specimen exhibited extremely high yield strength and a significantly reduced strain hardening rate. A lower strain hardening rate is more beneficial in delaying the necking point (maximum stress point) and the fracture point after reaching the ultimate true stress strength during the plastic deformation stage. Specifically, compared to the product obtained by 3D printing using the alloy material (Ti-6Al-4V) used in Example 1, the tensile strength of the specimen 3D printed using the alloy material prepared in Example 1 was increased by approximately 58%.

[0077] In addition, the nitrogen content in each group of tensile specimens was 0.19 wt.% and the oxygen content was 0.17 wt.%, and the nitrogen content of the alloy material prepared in Example 1 remained stable after 3D printing.

[0078] Example 2

[0079] The alloy material used in Example 2 is the same as that in Example 1, and the preparation method is similar. The difference from Example 1 is that the gas introduced in Example 2 is a mixed gas with a nitrogen content of 12%, wherein the gas other than nitrogen in the mixed gas is argon.

[0080] The stress-strain curve of the alloy material prepared in Example 2 is shown in Figure 4.

[0081] Example 3

[0082] The alloy material used in Example 3 is the same as that in Example 1, and the preparation method is similar. The difference from Example 1 is that in step 15 of Example 3, the temperature inside the furnace is raised from room temperature to 560°C at a heating rate of 5°C / min. In step 16, the temperature inside the furnace is raised from 560°C to 580°C at a heating rate of 2°C / min.

[0083] Example 4

[0084] The alloy material used in Example 4 is the same as that in Example 1, and the preparation method is similar. The difference from Example 1 is that in step 15 of Example 3, the temperature inside the furnace is raised from room temperature to 520°C at a heating rate of 10°C / min. In step 16, the temperature inside the furnace is raised from 520°C to 600°C at a heating rate of 2°C / min.

[0085] Example 5

[0086] Example 5 uses the same alloy material as Example 1, and the preparation method is similar. The difference from Example 1 is that in step 15 of Example 3, the temperature inside the furnace is raised from room temperature to 520°C at a heating rate of 10°C / min. In step 16, the temperature inside the furnace is raised from 520°C to 570°C at a heating rate of 2°C / min.

[0087] Example 6

[0088] The alloy material used in Example 6 is the same as that in Example 1, and the preparation method is similar. The difference from Example 1 is that in step 15 of Example 3, the temperature inside the furnace is raised from room temperature to 550°C at a heating rate of 15°C / min. In step 16, the temperature inside the furnace is raised from 550°C to 590°C at a heating rate of 1.5°C / min.

[0089] The alloy materials prepared in each of Examples 1-6 were tested and found to have a nitrided layer on their surface, and the thickness of the region in the nitrided layer with an atomic percentage of nitrogen ≥1 at.% was 1 μm-20 μm; and the mass fraction of nitrogen in the nitrided layer in the alloy material was ≥0.1 wt.% and ≤0.5 wt.%.

[0090] The alloy materials prepared in each of Examples 1-6 have an average yield strength exceeding 1400 MPa, a tensile strength of approximately 1500 MPa, and an elongation at break of 6-8%. The alloy materials prepared in each example can be used as raw materials for 3D printing, and the nitrogen content in the resulting products is the same as or close to that of the alloy material. Furthermore, compared to doping nitrogen into the raw materials during the 3D printing process, 3D printed products using the alloy materials prepared in the above examples as raw materials have fewer defects and a more uniform distribution of nitrogen and oxygen.

[0091] This application also provides an electronic device, which can be a terminal electronic device, such as a candybar phone, a foldable phone, a tablet computer, a laptop computer, a smart wearable device, etc. One or more components (e.g., the casing) of this electronic device can be made from the alloy material prepared in this application embodiment.

[0092] In some embodiments, the component is prepared using the alloy material prepared in the embodiments of this application as the printing material and manufactured by 3D printing technology.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of this application.

Claims

1. An alloy material, characterized by comprising: The surface of the alloy material has a nitrided layer, wherein the thickness of the region with an atomic percentage of nitrogen element ≥1 at.% in the nitrided layer is 1-20 μm; and the mass fraction of nitrogen element in the nitrided layer in the alloy material is ≥0.1 wt.% and ≤0.5 wt.%.

2. The alloy material according to claim 1, characterized in that, The alloy material is any one of a titanium-based alloy, an iron-based alloy, an aluminum-based alloy, and a copper-based alloy. Or, The particle size of the alloy material is 5-150 μm.

3. A method for producing the alloy material as claimed in claim 1 or 2, characterized in that, The method comprises: heating an alloy raw material to a preset temperature under a gas atmosphere with a nitrogen content of 5-100 vol.% and holding for a preset time length, so as to dope nitrogen element in the alloy raw material and obtain the alloy material.

4. The method of claim 3, wherein, The method for heating an alloy raw material to a preset temperature under a gas atmosphere with a nitrogen content of 5-100 vol.% and holding for a preset time length, so as to dope nitrogen element in the alloy raw material and obtain the alloy material, comprises: heating the alloy raw material to a first target temperature at a first heating speed under the gas atmosphere; heating the alloy raw material from the first target temperature to a second target temperature at a second heating speed under the gas atmosphere; wherein the second heating speed is less than the first heating speed, and the second target temperature is greater than the first target temperature; holding for the preset time length when the temperature of the alloy raw material reaches the second target temperature under the gas atmosphere, so as to dope nitrogen element in the alloy raw material and obtain the alloy material.

5. The method of claim 4, wherein, The first heating speed is 5-15 ℃ / min, the first target temperature is 520-570 ℃, the second heating speed is 1-2 ℃ / min, the second target temperature is 570-600 ℃ / min, and the preset time length is 20-100 min.

6. The method of claim 3, wherein, The method for heating an alloy raw material to a preset temperature under a gas atmosphere with a nitrogen content of 5-100 vol.% and holding for a preset time length, so as to dope nitrogen element in the alloy raw material and obtain the alloy material, comprises: heating the alloy raw material to a first target temperature at a first heating speed under the gas atmosphere; 7. The method according to any one of claims 3-6, characterized in that, heating the alloy raw material from the first target temperature to a second target temperature at a second heating speed under the gas atmosphere; wherein the second heating speed is less than the first heating speed, and the second target temperature is greater than the first target temperature; holding for the preset time length when the temperature of the alloy raw material reaches the second target temperature under the gas atmosphere, so as to dope nitrogen element in the alloy raw material and obtain the alloy material. The first heating speed is 5-15 ℃ / min, the first target temperature is 520-570 ℃, the second heating speed is 1-2 ℃ / min, the second target temperature is 570-600 ℃ / min, and the preset time length is 20-100 min. The method for heating an alloy raw material to a preset temperature under a gas atmosphere with a nitrogen content of 5-100 vol.% and holding for a preset time length, so as to dope nitrogen element in the alloy raw material and obtain the alloy material, comprises: heating the alloy raw material to a first target temperature at a first heating speed under the gas atmosphere; heating the alloy raw material from the first target temperature to a second target temperature at a second heating speed under the gas atmosphere; wherein the second heating speed is less than the first heating speed, and the second target temperature is greater than the first target temperature; holding for the preset time length when the temperature of the alloy raw material reaches the second target temperature under the gas atmosphere, so as to dope nitrogen element in the alloy raw material and obtain the alloy material. The first heating speed is 5-15 ℃ / min, the first target temperature is 520-570 ℃, the second heating speed is 1-2 ℃ / min, the second target temperature is 570-600 ℃ / min, and the preset time length is 20-100 min. The method for heating an alloy raw material to a preset temperature under a gas atmosphere with a nitrogen content of 5-100 vol.% and holding for a preset time length, so as to dope nitrogen element in the alloy raw material and obtain the alloy material, comprises: placing the alloy raw material in a hearth of a vacuum heat treatment furnace; introducing a gas with a nitrogen content of 5-100 vol.% into the hearth, so as to keep the hearth in the gas atmosphere and keep the hearth in a positive pressure state; heating the temperature of the hearth to the preset temperature and holding for the preset time length; when the holding ends, the furnace is cooled to 200-300 ℃, and then the furnace is opened and cooled to room temperature.

8. The method according to any one of claims 3-7, characterized in that, The alloy raw material is any one of titanium, iron, aluminum, copper, titanium-based alloy, iron-based alloy, aluminum-based alloy, and copper-based alloy. And / or, The particle size of the alloy raw material is 5-150 μm.

9. An electronic device, comprising: One or more components in the electronic device are prepared from the alloy material of claim 1 or 2.

10. The electronic device of claim 9, wherein, The components are prepared by 3D printing using the alloy material as a raw material.

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