High-strength, high-hardness and wear-resistant molybdenum-based material and preparation method thereof

Abstract

The invention relates to a preparation method of a high-strength, high-hardness and wear-resistant molybdenum-based material, which comprises the following preparation steps: S1, weighing raw material powder according to a ratio, the raw material powder comprises molybdenum-based powder and second-phase particles, and the addition amount of the second-phase particles is 0-5wt%; wherein the component of the molybdenum-based powder is Mo-xRe, x is the adding amount of Re, and x ranges from 0 wt% to 20 wt%; the second-phase particles are selected from at least one of carbide or boride powder of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo or W; s2, uniformly mixing the weighed raw material powder to obtain mixed powder; and S3, the molybdenum-based material is prepared from the mixed powder through powder metallurgy sintering or additive manufacturing. According to the molybdenum-based material prepared through the method, the strength, hardness and friction and wear resistance of molybdenum-rhenium alloy are improved on the whole, and the molybdenum-based material has good net formability, compactness, hardness, structure uniformity and wear resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of refractory metal composite materials, and in particular relates to a type of high-strength, high-hardness, wear-resistant molybdenum-based material and a preparation method thereof. Background Art

[0002] Molybdenum metal is widely used in aerospace, equipment manufacturing, the nuclear industry, and other fields due to its high melting point (2620°C), excellent high-temperature mechanical properties, high-temperature creep resistance, alkali metal compatibility, and good corrosion resistance. However, pure molybdenum has defects such as a body-centered cubic structure with few slip systems, high resistance to dislocation movement, and the accumulation of impurity elements at grain boundaries, making it difficult to improve the material's mechanical properties. Furthermore, its brittle-ductile transition temperature is near room temperature, making the material extremely brittle, further reducing its mechanical properties and limiting its use in the nuclear industry.

[0003] In order to effectively improve the mechanical properties of pure molybdenum, researchers currently usually use methods such as doping pure molybdenum with alloying elements such as rhenium and adding ZrO2 to improve its performance. For example, patent document No. 202411698701.7 discloses a molybdenum-rhenium alloy containing a zirconium dioxide reinforcement phase that inhibits abnormal grain growth and its preparation process. Liquid phase doping is used to achieve atomic-level mixing of molybdenum and rhenium. The addition of ZrO2 makes the microstructure of the molybdenum-rhenium alloy more uniform and fine, increases the recrystallization temperature, slows down the abnormal growth of sintered grains of the molybdenum-rhenium alloy, and improves the high-temperature tensile strength and elongation of the molybdenum-rhenium alloy. However, this method requires two stages of hydrogen reduction, cold treatment, etc. The static pressing, pressureless sintering, and hot isostatic pressing are used to obtain zirconium oxide-reinforced molybdenum-rhenium alloy, which is then subjected to high-temperature rolling and recrystallization annealing treatment. However, the preparation process is complex. Patent document No. 202510116664.2 discloses a method for synthesizing oxide-dispersed reinforced molybdenum-rhenium alloy by liquid-liquid doping process, which requires cold isostatic pressing, high-temperature hydrogen sintering, forging and swaging to obtain rods. This can significantly improve the performance of the alloy at high temperatures, but it also has the defect of a complex preparation process. Therefore, how to provide a method for preparing a molybdenum-based material that can simplify the process and obtain a molybdenum-based material with the comprehensive properties of high strength, high hardness and wear resistance has become a technical problem that needs to be solved urgently. Summary of the Invention

[0004] The purpose of the present invention is to provide a type of high-strength, high-hardness, wear-resistant molybdenum-based material and a preparation method, which can simplify the process and the prepared molybdenum-based material has good comprehensive properties.

[0005] In a first aspect, the present invention provides a method for preparing a high-strength, high-hardness, wear-resistant molybdenum-based material, comprising the following preparation steps:

[0006] S1. Weighing raw material powders according to a ratio, wherein the raw material powders include molybdenum-based powders and second-phase particles, and the amount of the second-phase particles added is 0-5 wt% based on the mass percentage of the raw material powders; wherein the composition of the molybdenum-based powder is Mo-xRe, where x is the amount of Re added, and x is 0-20 wt% based on the mass percentage of the molybdenum-based powders; and the second-phase particles are selected from at least one of carbide or boride powders of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, or W;

[0007] S2. The weighed raw material powders are mixed evenly to obtain a mixed powder;

[0008] S3. The mixed powder is sintered by powder metallurgy or additive manufacturing to obtain the molybdenum-based material.

[0009] Optionally, in step S1, x is 0.1-6.0 wt%.

[0010] Optionally, in step S1, the amount of the second phase particles added is 0.1 to 3.5 wt%, and the second phase particles are selected from at least one of TiB2, ZrB2 or ZrC.

[0011] Optionally, in step S1, the ratio of the particle sizes of the molybdenum-based powder and the second phase particles is 1-120 μm:50-900 nm.

[0012] Optionally, in step S3, the TiB2, ZrB2 or ZrC reacts with Mo of the molybdenum-based material to form a new Mo2B or Mo2C phase; and / or,

[0013] In step S3, the prepared molybdenum-based material is columnar crystals, and the average grain size of the columnar crystals is 40 to 45 μm.

[0014] Optionally, in step S1, the molybdenum-based powder is prepared by a rotating electrode atomization method, which specifically includes the following preparation steps:

[0015] S1-1. The Mo-xRe alloy rod is processed into a powder rod;

[0016] S1-2. Install the powder making rod into the powder making system and set the vacuum degree to 8.5×10 -3 Below Pa, the spindle speed is 20000-35000r / min, the feed rate is 0.5-2.5mm / s, the current is 10000-14000A, and the inert gas flow rate is 5-30L / min;

[0017] S1-3. After the powder is made, it is screened to obtain molybdenum-based powder.

[0018] Optionally, step S2. includes the following preparation steps:

[0019] S2-1. The raw material powder is mixed by vacuum dry ball milling, the vacuum degree is below 0.1 Pa, the rotation speed is 12-60 r / min, the ball milling time is 8-10 h, the ball-to-material ratio is 1:3-1:8, and the mixed powder is obtained after ball milling;

[0020] S2-2. The mixed powder is vacuum dried.

[0021] Optionally, the powder metallurgy sintering in step S3 adopts a spark plasma sintering process, the vacuum degree of sintering is below 10 Pa, the sintering temperature is 1500-1700℃, the heating rate is 80-150℃ / min, the sintering pressure is 35-45 Mpa, and the sintering time is 10-35 min. -2 Pa, the sintering temperature is 1500-1700℃, the heating rate is 80-150℃ / min, the sintering pressure is 35-45 Mpa, and the sintering time is 10-35 min.

[0022] Optionally, the additive manufacturing in step S3 adopts a laser selective melting process, which specifically includes the following steps:

[0023] S3-1. Preparing a transition layer: the substrate is preheated to 100-200℃, the printing environment is inert protective atmosphere, the oxygen content is controlled to be below 5 ppm, the stripe scanning strategy with an interlayer rotation angle of 60-90° is adopted, the laser power is 150-220 W, the scanning rate is 500-800 mm / s, the scanning pitch is 60-80 μm, the powder layer thickness is 20-40 μm, and the transition layer with a layer thickness of 0.3-0.8 mm is printed;

[0024] S3-2. Preparing a molybdenum-based material: the laser power is set to 325-410 W, the scanning rate is set to 250-500 mm / s, the scanning pitch is set to 70-100 μm, and the powder layer thickness is set to 20-40 μm, and the printing is continued on the transition layer.

[0025] In the second aspect, the application provides a molybdenum-based material obtained by the preparation method of the high-strength, high-hardness and wear-resistant molybdenum-based material.

[0026] In summary, the application has at least one of the following beneficial effects:

[0027] 1. The present invention provides a method for preparing a high-strength, high-hardness, wear-resistant molybdenum-based material. The molybdenum-rhenium alloy powder is prepared by a rotating electrode atomization method. The molybdenum-rhenium alloy powder has the advantages of high sphericity, no hollow powder, satellite powder, and low oxygen content (less than 0.03wt%); vacuum ball milling is used for drying, which has the advantages of reducing the introduction of impurity elements and avoiding oxidation of raw materials; SPS spark plasma sintering is used, which has the advantages of fast heating rate, simple operation, wide applicability, energy saving and environmental protection, and SLM has high production efficiency, flexible construction design, high precision manufacturing, and high material utilization rate; using specific elements and a second phase in combination with a specific preparation process, the prepared molybdenum-based material has good structural uniformity, fine grains, stable grain boundaries, high density, and reduced defects such as pores and cracks inside the material, thereby improving the hardness and strength of the material and reducing the adverse effects on the plasticity of the material.

[0028] 2. The present invention provides a method for preparing a high-strength, high-hardness, and wear-resistant molybdenum-based material. The preparation process is simple, and the molybdenum-based material has good comprehensive performance and can be used in heat pipes and cladding materials in nuclear reactors, high-temperature components of aircraft engines, heating elements and furnace tubes in high-temperature furnaces, and other field components. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 XRD patterns of molybdenum-based materials prepared by the powder metallurgy method of the present invention: (a) is the XRD pattern of the molybdenum-based material of Comparative Example 1; (b) is the XRD pattern of the molybdenum-based material of Examples 1-2; (c) is the XRD pattern of the molybdenum-based material of Examples 1-5; (d) is the XRD pattern of the molybdenum-based material of Examples 1-8;

[0030] Figure 2 The microstructure and element distribution diagram of the molybdenum-based materials prepared in Examples 1-2, 1-5, and 1-8 of the present invention;

[0031] Figure 3 The friction coefficient spectra of the molybdenum-based materials prepared in Examples 1-2, 1-5, and 1-8 of the present invention;

[0032] Figure 4 XRD patterns of the molybdenum-based materials prepared in Examples 2-1, 2-2, and 2-3 of the present invention;

[0033] Figure 5 Metallographic diagrams of molybdenum-based materials prepared in Examples 2-1, 2-2, and 2-3 of the present invention;

[0034] Figure 6 Element distribution diagram of the molybdenum-based material prepared in Example 2-3 of the present invention;

[0035] Figure 7These are the compression mechanical property test curves of the molybdenum-based materials prepared in Comparative Example 1, Examples 1-2, 1-5, and 1-8 of the present invention;

[0036] Figure 8 Compressive mechanical properties test curves of the molybdenum-based materials prepared in Examples 2-1, 2-2, and 2-3 of the present invention;

[0037] Figure 9 EBSD grain map and grain size distribution map of the molybdenum-based material prepared in Example 2-3 of the present invention. DETAILED DESCRIPTION

[0038] The present invention provides a high-strength, high-hardness, wear-resistant molybdenum-based material and a preparation method. To make the objectives, technical solutions, and effects of the present invention more clear and explicit, the present invention is further described below in detail. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention.

[0039] In some embodiments of the present invention, a method for preparing a high-strength, high-hardness, wear-resistant molybdenum-based material is provided, comprising the following preparation steps:

[0040] S1. Weighing raw material powders according to a ratio, wherein the raw material powders include molybdenum-based powders and second-phase particles, and the amount of the second-phase particles added is 0-5 wt% based on the mass percentage of the raw material powders; wherein the composition of the molybdenum-based powder is Mo-xRe, where x is the amount of Re added, and x is 0-20 wt% based on the mass percentage of the molybdenum-based powders; and the second-phase particles are selected from at least one of carbide or boride powders of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, or W;

[0041] S2. The weighed raw material powders are mixed evenly to obtain a mixed powder;

[0042] S3. The mixed powder is sintered by powder metallurgy or additive manufacturing to obtain the molybdenum-based material.

[0043] In some embodiments of the present invention, in step S1, x is 0.1-6.0 wt %; preferably, x is 2-6.0 wt %; more preferably, 3-5.0 wt %.

[0044] In some embodiments of the present invention, in step S1, the amount of the second phase particles added is 0.1 to 3.5 wt%; preferably 0.3 to 3.2 wt%; the second phase particles are selected from at least one of TiB2, ZrB2 or ZrC; preferably TiB2 or ZrB2; more preferably TiB2.

[0045] In some embodiments of the present invention, in step S1, the ratio of the particle size of the molybdenum-based powder and the second phase particles is 1-120 μm:50-900 nm; preferably, 1-110 μm:10-800 nm.

[0046] In some embodiments of the present invention, in step S3, the TiB2, ZrB2 or ZrC reacts with Mo of the molybdenum-based material to form a new Mo2B or Mo2C phase.

[0047] In some embodiments of the present invention, in step S3, the prepared molybdenum-based material is columnar crystals, and the average grain size of the columnar crystals is 40-45 μm.

[0048] In some embodiments of the present invention, in step S1., the molybdenum-based powder is prepared by a rotating electrode atomization method, which specifically includes the following preparation steps:

[0049] S1-1. The Mo-xRe alloy rod is processed into a powder rod;

[0050] S1-2. Install the powder making rod into the powder making system and set the vacuum degree to 8.5×10 -3 Pa below, the spindle speed is 20000-35000r / min, the feed rate is 0.5-2.5mm / s, the current is 10000-14000A, and the flow rate of the inert gas is 5-30L / min; preferably, the spindle speed is 21000-25000r / min, the feed rate is 0.8-1.5mm / s, the current is 11000-13000A, and the flow rate of the inert gas is 10-30L / min;

[0051] S1-3. After the powdering is completed, the powder is sieved to obtain a molybdenum-based powder. Preferably, the particle size of the molybdenum-based powder is 15-53 and 53-106 μm, preferably 53-106 μm.

[0052] In some embodiments of the present invention, step S2. includes the following preparation steps:

[0053] S2-1. The raw material powder is subjected to vacuum dry ball milling, the vacuum degree is 0.1Pa or less, the speed is 12-60r / min, the ball milling time is 8-10h, the ball-to-material ratio is 1:3~1:8, and the mixed powder is obtained after the ball milling is completed; preferably, the vacuum degree is 0.05Pa or less, the speed is 12-30r / min, the ball milling time is 8-19h, the ball-to-material ratio is 1:3~1:5, and the mixed powder is obtained after the ball milling is completed;

[0054] S2-2. The mixed powder is vacuum dried.

[0055] In some embodiments of the present invention, the powder metallurgy sintering in step S3 is carried out by spark plasma sintering process, and the vacuum degree of sintering is 10 -2 Pa, the sintering temperature is 1500-1700°C, the heating rate is 80-150°C / min, the sintering pressure is 35-45 MPa, and the sintering time is 10-35 min.

[0056] In some embodiments of the present invention, the additive manufacturing in step S3. adopts a laser selective melting process, which specifically includes the following steps:

[0057] S3-1. Preparation of transition layer: Preheat the substrate to 100-200°C, print in an inert atmosphere, control the oxygen content below 5ppm, use a stripe scanning strategy with an interlayer rotation angle of 60-90°, laser power of 150-220W, scanning rate of 500-800mm / s, scanning pitch of 60-80μm, powder layer thickness of 20-40μm, and print a transition layer with a thickness of 0.3-0.8mm.

[0058] S3-2. Preparation of molybdenum-based material: Continue printing on the transition layer, set the laser power to 325-410W, the scanning rate to 250-500mm / s, the scanning spacing to 70-100μm, and the powder layer thickness to 20-40μm.

[0059] The following is a detailed description with reference to the examples. Unless otherwise specified, the raw materials of the examples of the present invention are all commercially available.

[0060] Example 1-1

[0061] This embodiment provides a method for preparing a high-strength, high-hardness, wear-resistant molybdenum-rhenium-based material. The specific preparation steps are as follows:

[0062] S1. The raw material powder is weighed according to the ratio. The raw material powder includes a molybdenum-based powder and a second-phase particle. The amount of the second-phase particle added is 1wt% by mass percentage of the raw material powder. The second-phase particle is TiB2 (purity of 99.99%, particle size of 10-800nm), the composition of the molybdenum-based powder is Mo-xRe, x is the amount of Re added, x is 0, and the molybdenum-based powder is pure molybdenum Mo powder (purity of 99.99%, particle size of 1-10μm);

[0063] S2. The weighed raw material powder was mixed using a three-dimensional mixer for 10h, the mixing speed was 60r / min, the mixing was vacuum (vacuum degree 0.05Pa), and after mixing, a mixed powder was obtained;

[0064] S3. The mixed powder was placed in a spark plasma sintering furnace for sintering. The sintering process settings were: heating rate of 101°C / min, sintering temperature of 1600°C; sintering pressure of 30 MPa; holding time of 20 min; vacuum degree of 5*10 -2 In the following, a molybdenum-based material was prepared.

[0065] Example 1-2

[0066] The difference between Example 1-2 and Example 1-1 is that in step S1, the addition amount of the second phase particles is 3 wt %, and the remaining preparation steps are the same as those of Example 1-1 to prepare a molybdenum-based material.

[0067] Examples 1-3

[0068] The difference between Example 1-3 and Example 1-1 is that in step S1, the addition amount of the second phase particles is 5 wt %, and the remaining preparation steps are the same as those of Example 1-1 to prepare a molybdenum-based material.

[0069] Examples 1-4

[0070] The difference between Example 1-4 and Example 1-1 is that in step S1, the second phase particles are replaced by equal mass of ZrB2 (purity of 99.99%, particle size of 10-800nm) instead of TiB2, and the remaining preparation steps are the same as Example 1-1 to prepare a molybdenum-based material.

[0071] Examples 1-5

[0072] The difference between Example 1-5 and Example 1-4 is that in step S1, the amount of the second phase particles added is 3 wt %, and the remaining preparation steps are the same as those of Example 1-4 to prepare a molybdenum-based material.

[0073] Examples 1-6

[0074] The difference between Example 1-6 and Example 1-4 is that in step S1, the addition amount of the second phase particles is 5 wt %, and the remaining preparation steps are the same as those of Example 1-4 to prepare a molybdenum-based material.

[0075] Examples 1-7

[0076] The difference between Example 1-7 and Example 1-1 is that in step S1, the second phase particles are replaced by equal mass of ZrC (purity of 99.99%, particle size of 10-800nm) instead of TiB2, and the remaining preparation steps are the same as Example 1-1 to prepare a molybdenum-based material.

[0077] Examples 1-8

[0078] The difference between Example 1-8 and Example 1-7 is that in step S1, the amount of the second phase particles added is 3 wt %, and the remaining preparation steps are the same as those of Example 1-7 to prepare a molybdenum-based material.

[0079] Example 9

[0080] The difference between Example 1-9 and Example 1-7 is that in step S1, the amount of the second phase particles added is 5 wt %, and the remaining preparation steps are the same as those of Example 1-7 to prepare a molybdenum-based material.

[0081] Comparative Example 1

[0082] The difference between Comparative Example 1 and Example 1-1 is that in step S1, the amount of the second phase particles added is 0. The specific preparation steps are as follows:

[0083] S1 'weighed raw material powder according to the ratio, the raw material powder is a molybdenum-based powder, the molybdenum-based powder composition is pure molybdenum Mo (purity of 99.99%, particle size of 1-10μm);

[0084] S3 '. The raw material powder is placed in a spark plasma sintering furnace for sintering. The sintering process is set to: a heating rate of 101 ℃ / min, a sintering temperature of 1600 ℃; a sintering pressure of 30Mpa; a holding time of 20min; a vacuum degree of 5*10 -2 In the following, a molybdenum-based material was prepared.

[0085] Example 2-1

[0086] This embodiment provides a method for preparing a high-strength, high-hardness, wear-resistant molybdenum-rhenium-based material. The specific preparation steps are as follows:

[0087] S1. Weigh raw powders according to a ratio, wherein the raw powders include molybdenum-based powders and second-phase particles, wherein the second-phase particles are added in an amount of 0.5 wt% based on the mass percentage of the raw powders, and the second-phase particles are TiB2; wherein the composition of the molybdenum-based powder is Mo-xRe, where x is the amount of Re added, and x is 5 wt% based on the mass percentage of the molybdenum-based powder; wherein the molybdenum-based powder is prepared by a rotating electrode atomization method, specifically comprising the following preparation steps:

[0088] S1-1 The Mo-5Re alloy rod (size Φ31mm × 161mm, raw materials purchased from Shandong Gemei Tungsten Molybdenum Materials Co., Ltd.) processed into powder rods (size Φ31mm × 107mm);

[0089] S1-2. Install the powder making rod into the powder making system (plasma rotating electrode powder making equipment, SLPA-D) and set the vacuum degree to 8.5×10 -3Pa below, spindle speed is 23000r / min, feed rate is 1.0mm / s, current is 12000A, inert gas flow rate is 20L / min, and pulverizing is completed;

[0090] S1-3. After the powdering is completed, it is screened to obtain Mo-5Re molybdenum-rhenium-based powders with particle sizes of 15-53 and 53-106 μm. The Mo-5Re molybdenum-rhenium-based powder with a particle size of 53-106 μm is selected as the molybdenum-rhenium-based powder for subsequent selective laser melting.

[0091] S2. Mix the weighed raw material powders evenly to obtain a mixed powder, which specifically includes the following steps: S2-1. Subject the raw material powders to vacuum dry ball milling, with a vacuum degree of 0.05 Pa, a rotation speed of 12 r / min, a ball milling time of 8 h, and a ball-to-material ratio of 1:5. After the ball milling is completed, a mixed powder is obtained; S2-2. Vacuum dry the mixed powder, with a vacuum degree of 0.05 Pa, a temperature of 60°C, and a time of 6 h.

[0092] S3. preparing a molybdenum-based material from the mixed powder by additive manufacturing, specifically comprising the following steps:

[0093] S3-1. Preparation of transition layer: The mixed powder was placed in the powder feeding system of a laser powder bed fusion equipment (Hanbang) for printing. The 316L stainless steel substrate was preheated to 150°C. The printing environment was an inert (argon) protective atmosphere with an oxygen content controlled below 5 ppm. A stripe scanning strategy with an interlayer rotation angle of 67° was adopted. The laser power was set to 180 W, the scanning rate was set to 700 mm / s, the scanning pitch was 70 μm, the powder layer thickness was 30 μm, and a transition layer with a thickness of 0.5 mm was printed.

[0094] S3-2. Preparation of molybdenum-based materials: Print molybdenum-based materials on the transition layer, set the laser power to 380W, the scanning rate to 400mm / s, the scanning spacing to 90μm, and the powder layer thickness to 30μm. After printing, remove the stainless steel substrate and the sample on it, separate the stainless steel substrate from the sample by wire cutting, and remove the transition layer to prepare the molybdenum-based material.

[0095] Example 2-2

[0096] The difference between Example 2-2 and Example 2-1 is that in step S3-2, the laser power is set to 380W, the scanning rate is 300mm / s, the scanning spacing is 80μm, and the powder layer thickness is 30μm. The remaining preparation steps are the same as Example 2-1 to prepare a molybdenum-based material.

[0097] Example 2-3

[0098] The difference between Example 2-3 and Example 2-1 is that in step S3-2, the laser power is set to 375W, the scanning rate is 250mm / s, the scanning spacing is 80μm, and the powder layer thickness is 30μm. The remaining preparation steps are the same as Example 2-1 to prepare a molybdenum-based material.

[0099] The volume energy density of Examples 2-1, 2-2, and 2-3 was calculated to be 351 J / mm by the formula VED=P / (v*h*t), where VED represents the volume energy density, P is the laser power, v is the scanning speed, h is the scanning spacing, and t is the thickness of the powder layer. 3 ,527J / mm 3 , 625J / mm 3 .

[0100] The phase composition structure of the molybdenum-based materials prepared in Examples 1-2, 1-5, 1-8 and Comparative Example 1 was tested by X-ray diffractometer. The test results are as follows: Figure 1 As shown, from Figure 1 As can be seen from (a), in Comparative Example 1, there are no second phase particles, and the phase composition of the prepared molybdenum-based material is a single phase of Mo, and Mo is a body-centered cubic structure; Figure 1 As can be seen from (b), in Example 1-2, 3 wt% of the second phase particles TiB2 were added, and the phase composition of the prepared molybdenum-based material was mainly Mo matrix and Mo2B phase. The main phase Mo matrix maintained a body-centered cubic structure, indicating that the added TiB2 reacted with Mo to form a new phase Mo2B. Figure 1 As can be seen from (c), in Examples 1-5, 3 wt% of the second phase particles ZrB2 were added, and the phase composition of the prepared molybdenum-based materials was mainly Mo matrix and second phase Mo2B, indicating that ZrB2 reacted with Mo to form a new phase Mo2B; the main phase Mo matrix maintained a body-centered cubic structure; Figure 1 As can be seen from (d), in Examples 1-8, 3 wt% of the second phase particles ZrC were added, and the phase composition of the prepared molybdenum-based material was a main phase Mo matrix and a Mo2C phase. The main phase Mo matrix maintained a body-centered cubic structure, indicating that ZrC reacted with Mo to form a new phase Mo2C.

[0101] The microstructure and element distribution of the molybdenum-based materials prepared in Examples 1-2, 1-5, and 1-8 were tested using a scanning electron microscope (SEM). The test results are shown in FIG. Figure 2 As shown, combined with the above-mentioned analysis of the phase composition structure of the molybdenum-based material and Figure 2From the microstructure and element distribution, it can be known that in Example 1-2, 3wt% of second-phase particles TiB2 are added, and the prepared molybdenum-based material includes Mo matrix, TiB2 particles distributed in the Mo matrix, and a new phase Mo2B formed by the reaction of the Mo matrix and TiB2 particles; in Example 1-5, 3wt% of second-phase particles ZrB2 are added, and the prepared molybdenum-based material includes Mo matrix, ZrB2 particles distributed in the Mo matrix, and a new phase Mo2B formed by the reaction of the Mo matrix and ZrB2; in Example 1-8, 3wt% of second-phase particles ZrC are added, and the prepared molybdenum-based material includes Mo matrix, ZrC particles distributed in the Mo matrix, and a new phase Mo2C formed by the reaction of the Mo matrix and ZrC.

[0102] The friction and wear test was conducted using a Bruker UMT Tribolab friction and wear tester at room temperature, with a friction pair of spherical Al2O3, a load of 10N, a frequency of 15Hz, a friction time of 15min, and a reciprocating stroke of 8mm. The friction and wear tests were conducted on the samples of the molybdenum-based materials prepared in Test Examples 1-2, 1-5, and 1-8. The test curves are shown in FIG. Figure 3 As shown, the friction coefficients of Examples 1-2, 1-5, and 1-8 were measured to be 0.466, 0.524, and 0.568, respectively, which are significantly lower than the friction coefficient of pure molybdenum of 0.7. It can be seen that the addition of second phase particles to pure molybdenum can significantly improve the wear resistance of the material. Among them, the friction coefficient after adding TiB2 is the lowest and the friction performance is the best. The friction performance after adding ZrB2 is better, and the friction performance after adding ZrC is second. All of them provide a certain performance basis for molybdenum alloys to serve in wear-resistant environments.

[0103] The phase composition structure of the molybdenum-based materials prepared in Examples 2-1, 2-2, and 2-3 was tested by X-ray diffractometer. The test results are as follows: Figure 4 As shown, from Figure 4 It can be seen that the physical phase composition structure of the molybdenum-based materials prepared in Examples 2-1, 2-2, and 2-3 is all a single phase of Mo, Mo is a body-centered cubic structure, and the relative intensity of the characteristic diffraction peak of the (200) crystal plane gradually increases, indicating that the degree of orientation along the (200) crystal plane increases. Due to the small amount of second phase particles added, no second phase was detected.

[0104] The microstructure of the molybdenum-based materials prepared in Examples 2-1, 2-2, and 2-3 was tested using an optical microscope (OM). The test results are as follows: Figure 5 As shown, from Figure 5 It can be seen that the molybdenum-based material structure of Example 2-1 is basically dense, but there are some unmelted holes and cracks; the molybdenum-based material structures of Examples 2-2 and 2-3 are more dense, with a small number of keyholes or pores, and no cracks are observed.

[0105] The element distribution of the molybdenum-based materials of Examples 2-3 parallel to the printing direction was tested using a scanning electron microscope (SEM). The test results are as follows: Figure 6 As shown, it can be seen that the various elements in the molybdenum-based material are evenly distributed.

[0106] In the embodiments and comparative examples of the present invention, an automatic turret Vickers hardness tester (model: 452SVA) was used, and the indenter was a regular quadrangular pyramid diamond indenter. The test force was 5 kgf to test the hardness of the molybdenum-based materials of Examples 1-1 to 1-9 and Comparative Example 1. The test force was 1 kgf to test the hardness of the molybdenum-based materials of Examples 2-1 to 2-3. The loading time was 10 s. The test method was in accordance with the national standard GB / T 4340.1-2024. A special balance (model: ATX224) was used to measure the density of the sample according to the Archimedes drainage method. A universal electronic testing machine (model: C45.105Y) was used to test the mechanical properties of the sample. The experimental rate was 0.2 mm / min, the preload was 30 N, and the test method was in accordance with the national standard GB / T 7314-2017. The measured partial stress-strain curves are shown in Figure 2. Figure 7 and Figure 8 The specific performance test data is shown in Table 1.

[0107] Table 1 Properties of molybdenum-based materials

[0108]

[0109] It can be seen from Table 1 that, in combination with Comparative Example 1 and Examples 1-1, 1-2 and 1-3, the density of the prepared molybdenum-based material is high, and with the increase in the amount of the second-phase particle TiB2 added, the hardness, yield strength and compressive strength of the molybdenum-based material gradually increase, but the compressive strain first increases slightly and then decreases significantly, indicating that the plasticity of the material decreases, which is mainly due to the dispersion strengthening effect and grain boundary stabilization effect of TiB2 and Mo2B, which increase the hardness and strength but reduce the plasticity of the material; in combination with Comparative Example 1, Examples 1-4, 1-5 and 1-6, it can be seen that the density of the prepared molybdenum-based material is high, and with the increase in the amount of the second-phase particle ZrB2 added, the hardness, yield strength and compressive strength of the molybdenum-based material gradually increase, but the compressive strain first increases slightly and then decreases significantly, indicating that the plasticity of the material decreases. The hardness, yield strength and compressive strength of the molybdenum-based material gradually increase, but the compressive strain first decreases significantly, indicating that the plasticity of the material decreases. This is mainly due to the dispersion strengthening and grain boundary stabilization of ZrB2 and Mo2B, which improve the hardness and strength but reduce the plasticity of the material. Combining Comparative Example 1, Examples 1-7, 1-8 and 1-9, it can be seen that the prepared molybdenum-based material has a high density, and with the increase in the addition amount of the second phase particles ZrC, the hardness, yield strength and compressive strength of the molybdenum-based material gradually increase, but the compressive strain first decreases and then increases. This is mainly due to the dispersion strengthening and grain boundary stabilization of ZrC and Mo2C, which improve the hardness and strength but reduce the plasticity of the material. Combining Examples 1-1 to 1-9, it can be seen that the hardness and compressive strength of the molybdenum-based material with the addition of the second phase particles TiB2 are the highest, and the comprehensive performance is the best. In particular, the addition of 1wt% TiB2 has better hardness and compressive strength, as well as the best plasticity. The second is the addition of 3wt% ZrC, which has better hardness and compressive strength, as well as the best plasticity.

[0110] In combination with Examples 2-1, 2-2 and 2-3, it can be seen that the prepared molybdenum-based material has high density, high hardness, yield strength and compressive strength, indicating that the addition of alloying elements Re and second-phase particles TiB2 to the Mo base combined with specific selective laser melting process parameters can improve the hardness, yield strength and compressive strength of the Mo-based material, and can reduce the adverse effects on the plasticity of the material. In particular, in Example 2-2, the prepared molybdenum-based material has the best plasticity and the compressive strength reaches more than 1.2GPa.

[0111] The molybdenum-based materials in Examples 2-3 were characterized by EBSD. Figure 9 As shown in the figure, although the microstructure of the molybdenum-based material is still columnar crystals, it is different from the common columnar crystals (about 200μm). After adding the second phase particles, the columnar crystals are suppressed and the grains are refined. Using the equivalent circle diameter algorithm, the grain size range is 1.43-89.72μm, and the average grain size is 42μm.

[0112] The above are all preferred embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a high-strength, high-hardness, wear-resistant molybdenum-based material, characterized in that: The method comprises the following preparation steps: S1. Weighing raw material powders according to a ratio, wherein the raw material powders include molybdenum-based powders and second-phase particles, and the amount of the second-phase particles added is 0-5 wt% based on the mass percentage of the raw material powders; wherein the composition of the molybdenum-based powder is Mo-xRe, where x is the amount of Re added, and x is 0-20 wt% based on the mass percentage of the molybdenum-based powders; and the second-phase particles are selected from at least one of carbide or boride powders of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, or W; S2. The weighed raw material powders are mixed evenly to obtain a mixed powder; S3. The mixed powder is sintered by powder metallurgy or additive manufacturing to obtain the molybdenum-based material.

2. The method for preparing a high-strength, high-hardness, wear-resistant molybdenum-based material according to claim 1, characterized in that: In step S1, x is 0.1-6.0 wt%.

3. The method for preparing a high-strength, high-hardness, wear-resistant molybdenum-based material according to claim 1 or 2, characterized in that: In step S1, the amount of the second phase particles added is 0.1 to 3.5 wt%, and the second phase particles are selected from at least one of TiB2, ZrB2 or ZrC.

4. The method for preparing a high-strength, high-hardness, wear-resistant molybdenum-based material according to claim 1, wherein: In step S1 , the ratio of the particle sizes of the molybdenum-based powder and the second phase particles is 1-120 μm:50-900 nm.

5. The method for preparing a high-strength, high-hardness, wear-resistant molybdenum-based material according to claim 1, wherein: In step S3, the TiB2, ZrB2 or ZrC reacts with Mo of the molybdenum-based material to form a new Mo2B or Mo2C phase; and / or, In step S3, the prepared molybdenum-based material is columnar crystals, and the average grain size of the columnar crystals is 40 to 45 μm.

6. The method for preparing a high-strength, high-hardness, wear-resistant molybdenum-based material according to claim 1, characterized in that: In step S1, the molybdenum-based powder is prepared by a rotating electrode atomization method, which specifically includes the following preparation steps: S1-1. The Mo-xRe alloy rod is processed into a powder rod; S1-2. Install the powder making rod into the powder making system and set the vacuum degree to 8.5×10 -3 Below Pa, the spindle speed is 20000-35000r / min, the feed rate is 0.5-2.5mm / s, the current is 10000-14000A, and the inert gas flow rate is 5-30L / min; S1-3. After the powder is made, it is screened to obtain molybdenum-based powder.

7. The method for preparing a high-strength, high-hardness, wear-resistant molybdenum-based material according to claim 1, characterized in that: Step S2. includes the following preparation steps: S2-1 The raw material powder was vacuum dry milled and mixed, the vacuum degree was 0.1Pa or less, the number of revolutions was 12-60r / min, the milling time was 8-10h, the ball-to-material ratio was 1:3 to 1:8, and the mixed powder was obtained after the milling was completed; S2-2. The mixed powder is vacuum dried.

8. The method for preparing a high-strength, high-hardness, wear-resistant molybdenum-based material according to claim 1, characterized in that: The powder metallurgy sintering in step S3 is carried out by spark plasma sintering process, and the vacuum degree of sintering is 10 -2 Pa, the sintering temperature is 1500-1700°C, the heating rate is 80-150°C / min, the sintering pressure is 35-45 MPa, and the sintering time is 10-35 min.

9. The method for preparing a high-strength, high-hardness, wear-resistant molybdenum-based material according to claim 1, characterized in that: The additive manufacturing in step S3. adopts a laser selective melting process, which specifically includes the following steps: S3-1. Preparation of transition layer: Preheat the substrate to 100-200°C, print in an inert atmosphere, control the oxygen content below 5ppm, use a stripe scanning strategy with an interlayer rotation angle of 60-90°, laser power of 150-220W, scanning rate of 500-800mm / s, scanning pitch of 60-80μm, powder layer thickness of 20-40μm, and print a transition layer with a thickness of 0.3-0.8mm. S3-2. Preparation of molybdenum-based material: Continue printing on the transition layer, set the laser power to 325-410W, the scanning rate to 250-500mm / s, the scanning spacing to 70-100μm, and the powder layer thickness to 20-40μm.

10. A molybdenum-based material obtained by the preparation method of the high-strength, high-hardness, wear-resistant molybdenum-based material according to any one of claims 1 to 9.

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