Method for refining grains on surface of tungsten material based on friction induction and application

Abstract

The invention relates to the technical field of tungsten metal surface refinement, in particular to a method for refining grains on the surface of a tungsten material based on friction induction and application, and the method achieves grain refinement on the surface of refractory metal through the shear friction force and the thermal-mechanical coupling effect. Firstly, a tungsten material sample is in contact with a friction pair of a friction instrument, then a certain pressure is applied to the surface of the tungsten material through the friction pair, the material is heated to a preset temperature through a temperature control module, then rotary friction is conducted at a certain rotating speed, and after a period of time, a nanoscale gradient structure layer can be formed on the surface of the sample. By means of the method, the grain size can be refined to the nanometer level from the initial micrometer level, and the surface hardness of the material is greatly improved. The method is simple in process, low in cost and obvious in grain refinement effect, and has important engineering application value.

Description

Technical Field

[0001] The present invention belongs to the technical field of tungsten metal surface refinement, and particularly relates to a method and application for surface grain refinement of tungsten materials based on friction-induced Background Art

[0002] Tungsten and its alloys have wide application prospects in the fields of national defense and military, aerospace, electronic information, etc. due to their high melting point (3410 °C), excellent high-temperature resistance, high thermal conductivity and anti-irradiation performance. Typical applications include armor-piercing projectiles in national defense and military, the first-wall material in advanced fusion reactors, and electrical heating elements in the electrical industry. However, due to the inherent brittleness, low ductility of tungsten materials, and the easy occurrence of irradiation embrittlement damage in the irradiation environment, etc., the application prospects and service life of tungsten materials are severely limited. Research has found that surface grain refinement treatment of tungsten materials can significantly improve their hardness, anti-irradiation performance and anti-fatigue performance. Therefore, surface strengthening has become an extremely important step in the manufacture of key components. Developing an efficient and low-cost refractory metal surface refinement technology is of great significance for improving the comprehensive performance of tungsten materials.

[0003] Currently, the main methods for surface refinement of metal materials are: mechanical shot peening strengthening technology, laser shock peening technology, ultrasonic shock technology, etc. Mechanical shot peening technology uses high-speed projectiles to impact the surface of metal materials at high frequency to induce severe plastic deformation to achieve grain refinement. However, the surface plastic deformation amount of this method is small, and the grain strengthening effect is limited. In addition, the manufacturing cost of shot peening equipment is relatively high, and the power consumption is large and the efficiency is low, which restricts its application scope to a certain extent. Laser shock peening technology uses the plasma shock wave induced by high-energy laser to generate a nano-gradient structure on the metal surface. However, the process parameters of this method are complex and the equipment cost is high, which restricts its large-scale application. Ultrasonic shock technology uses ultrasonic vibration and mechanical shock to process the metal surface to refine the surface grains, but the disadvantage is that the equipment cost is high and the process parameters need to be precisely controlled during the treatment process.

[0004] The prior art has disclosed some methods for metal surface refinement. For example, the patent application No. CN202011461341.0 discloses a method for ultra-fine grain refinement of the surface of metal materials. This method requires the metal materials to undergo nitriding treatment, quenching treatment, nitriding treatment, and quenching treatment, and finally the surface grains of the obtained metal materials are about 1 μm. Although the above method can refine the surface grains of metal materials, the efficiency is low, the process complexity is high, multiple steps are required for surface grain refinement treatment, and the refinement area is uncontrollable, and the depth of the grain refinement layer is relatively shallow, ultimately affecting the use performance of the materials, and the cost is relatively high.

[0005] For the surface grain refinement method of tungsten materials, traditional methods include equal-channel angular pressing, high-pressure rotation, die casting, rotary forging, etc. For example, as reported in the article "Mengxia Liang, Shaowei Dai, Jiupeng Song, etc. Evolution of potassium bubbles and its influences on the recrystallization behaviour of swaged tungsten rods with high potassium doping level[J]. International Journal of Refractory Metals and Hard Materials 111(2023)106117.", tungsten alloy rods containing 96 ppm potassium were prepared by rotary forging. When the logarithmic strain was 3.53, the average grain size of the swaged tungsten alloy was 2.1 μm, and the corresponding material hardness was about 437 HV. Another example is the article "R. Liu, Z.M. Xie, X.Y. Yao, etc. Effects of swaging and annealing on the microstructure and mechanical properties of ZrC dispersion-strengthened tungsten[J]. International Journal of Refractory Metals & Hard Materials 76(201

[0006] 8)33–40.", which reported that a W-0.5% ZrC alloy was prepared by rotary forging. Its average grain size in the axial direction was 35 μm, and the average grain size in the radial direction was 7 μm. In addition, this literature reported that the hardness of the W-0.5% ZrC prepared by rotary forging in the axial direction was 452 HV.

[0007] To further reduce the grain size on the surface of tungsten materials and improve the hardness of tungsten alloys after grain refinement, the present invention proposes a method and application for surface grain refinement of tungsten materials based on friction induction. Summary of the Invention

[0008] Aiming at the problems of complex traditional metal surface grain refinement methods, high costs, and limited grain refinement degree, the object of the present invention is to provide a method and application for surface grain refinement of tungsten materials based on friction induction, which can further reduce the grain size on the surface of tungsten materials and improve the hardness of tungsten alloys after grain refinement.

[0009] The present invention achieves the above object through the following technical solutions:

[0010] The present invention provides a method for surface grain refinement of tungsten materials induced by friction. At room temperature or under heating conditions, a contact load is applied to the surface of the tungsten material by a friction member and rotated to obtain a tungsten material with surface grain refinement.

[0011] As a further optimized solution, it specifically includes the following steps:

[0012] (1) Grind the tungsten material to remove surface impurities, and then fix the tungsten material on a friction instrument;

[0013] (2) Assemble a friction pair on the mechanical sensor of the friction instrument, apply a certain value of vertical load to the plane of the tungsten material through the friction pair, so that the friction pair generates contact pressure with the surface of the tungsten material;

[0014] (3) Keep the tungsten material at room temperature or heat the tungsten material to a set value, and control the temperature of the tungsten material to remain constant;

[0015] (4) Rotate the tungsten material obtained in step (3) at a certain rotational speed, so that the surface of the tungsten material frictions with the friction pair, inducing surface grain refinement of the tungsten material.

[0016] As a further optimized solution, the tungsten content in the tungsten material is ≥ 85%.

[0017] As a further optimized solution, in step (1), the grinding method of the tungsten material is: successively use 400-mesh, 800-mesh, 1500-mesh, and 2000-mesh silicon carbide sandpaper to grind the surface of the tungsten material to remove surface impurities and make its surface smooth.

[0018] As a further optimized solution, in step (2), the friction pair material is alumina ceramic or silicon nitride ceramic.

[0019] As a further optimized solution, in step (2), the load value range is 10 N - 100 N.

[0020] As a further optimized solution, in step (3), the temperature setting range of the tungsten material is room temperature - 600 °C. The tungsten material can be further heated by a resistance wire, and the temperature is controlled to remain constant through a temperature sensor.

[0021] As a further optimized solution, in step (4), by setting the rotation speed and friction action time of the tungsten material on the friction instrument, the rotation speed range of the tungsten material is 100 r / min - 600 r / min, and the friction action time range is 5 min - 30 min.

[0022] As a second aspect of the present invention, a high-hardness tungsten material prepared by any of the above methods is also provided.

[0023] As a further optimized solution, the hardness of the tungsten material is > 500 HV.

[0024] The beneficial effects of the present invention are as follows:

[0025] (1) Innovatively, through the multi-field coupling action of load, rotation speed, and temperature on the tungsten material, a high-strength frictional energy field is constructed on the surface of the tungsten material, inducing severe superplastic deformation locally in the material, and realizing surface grain refinement by combining dynamic recrystallization. This technology realizes the refinement of the grain size on the surface of the tungsten material from the initial 1.6 μm to 155 nm, forming a grain refinement layer with a maximum thickness of 15.7 μm and a continuous gradient structure. Compared with traditional surface nanocrystallization technologies, the present invention can complete the grain refinement of the material and construct a gradient structure refinement layer in a simple process. Through the present invention, the Vickers hardness on the surface of the tungsten material can be increased from the initial 442 HV to 591 HV, with a hardness increase of 149 HV and a hardening rate of 33.7%, which provides an efficient and low-cost solution for the surface strengthening of high-melting-point metals.

[0026] (2) By rotating and rubbing the surface of the tungsten material, instantaneous shear is generated by the high-speed rotation of the material and the friction pair, promoting the rapid annihilation of dislocations and the formation of nanocrystals. This extreme strain rate will trigger a competition mechanism between the rapid proliferation of dislocations and dynamic recovery, forming a finer sub-boundary structure, which is different from the quasi-static deformation of traditional methods such as equal-channel angular pressing, high-pressure rotation, and rotary forging, and can take into account both the improvement of surface hardness and the stability of the overall performance of the material.

[0027] (3) The method for surface refinement of tungsten material by rotational friction disclosed in the present invention is particularly suitable for components that require surface grain refinement treatment but keep the interior unchanged. In addition, rotational friction does not require complex molds or heavy forging equipment, greatly reducing the cost. Description of the Drawings

[0028] Figure 1 It is a schematic diagram of the method for friction-induced surface grain refinement of tungsten material according to the present invention; among them, (a) is a schematic diagram of the rotational friction of the tungsten material; (b) is a schematic diagram of the surface grains and refinement layer after the rotational friction of the tungsten material.

[0029] Figure 2 It is the SEM image and size distribution diagram of the grains of pure tungsten before rotational friction in Example 1 of the present invention;

[0030] Figure 3 It is the BSE image of the surface grains of pure tungsten after rotational friction in Example 1 of the present invention;

[0031] Figure 4 are the EBSD images and size statistics results of the surface grains of pure tungsten after rotational friction in Example 1 of the present invention;

[0032] Figure 5 is the SEM image of the grain refinement layer of pure tungsten after rotational friction in Example 1 of the present invention;

[0033] Figure 6 is the Vickers hardness map of the surface of pure tungsten before and after rotational friction in Example 1 of the present invention;

[0034] Figure 7 are the SEM image and size distribution map of the grains of pure tungsten before rotational friction in Example 2 of the present invention;

[0035] Figure 8 is the BSE image of the surface grains of pure tungsten after rotational friction in Example 2 of the present invention;

[0036] Figure 9 are the EBSD images and size statistics results of the surface grains of pure tungsten after rotational friction in Example 2 of the present invention;

[0037] Figure 10 is the SEM image of the grain refinement layer of pure tungsten after rotational friction in Example 2 of the present invention;

[0038] Figure 11 is the Vickers hardness map of the surface of pure tungsten before and after rotational friction in Example 2 of the present invention;

[0039] Figure 12 are the SEM image and size distribution map of the grains of pure tungsten before rotational friction in Example 3 of the present invention;

[0040] Figure 13 is the BSE image of the surface grains of pure tungsten after rotational friction in Example 3 of the present invention;

[0041] Figure 14 are the EBSD images and size statistics results of the surface grains of pure tungsten after rotational friction in Example 3 of the present invention;

[0042] Figure 15 is the SEM image of the grain refinement layer of pure tungsten after rotational friction in Example 3 of the present invention;

[0043] Figure 16 is the Vickers hardness map of the surface of pure tungsten before and after rotational friction in Example 3 of the present invention;

[0044] Figure 17 are the SEM image and size distribution map of the grains of pure tungsten before rotational friction in Example 4 of the present invention;

[0045] Figure 18It is the BSE image of the surface grains of pure tungsten after rotational friction in Example 4 of the present invention;

[0046] Figure 19 It is the EBSD image and size statistical result of the surface grains of pure tungsten after rotational friction in Example 4 of the present invention;

[0047] Figure 20 It is the SEM image of the grain refinement layer of pure tungsten after rotational friction in Example 4 of the present invention;

[0048] Figure 21 It is the Vickers hardness map of the surface of pure tungsten before and after rotational friction in Example 4 of the present invention;

[0049] Figure 22 It is the SEM image and size distribution map of the grains of W-0.5% ZrC before rotational friction in Example 5 of the present invention;

[0050] Figure 23 It is the BSE image of the surface grains of W-0.5% ZrC after rotational friction in Example 5 of the present invention;

[0051] Figure 24 It is the EBSD image and size statistical result of the surface grains of W-0.5% ZrC after rotational friction in Example 5 of the present invention;

[0052] Figure 25 It is the SEM image of the grain refinement layer of W-0.5% ZrC after rotational friction in Example 5 of the present invention;

[0053] Figure 26 It is the Vickers hardness map of the surface of W-0.5% ZrC before and after rotational friction in Example 5 of the present invention. Detailed implementation manners

[0054] The present invention will be further described in detail below with reference to the accompanying drawings. It is necessary to point out here that the following detailed implementation manners are only used to further illustrate the present invention and cannot be understood as limiting the protection scope of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention according to the above application content.

[0055] The methods used in the present invention are all conventional methods known to those skilled in the art unless otherwise specified. For those without specific conditions, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. For the materials or instruments without indicating the manufacturer, they are all products that can be obtained through commercial purchase.

[0056] Example 1

[0057] The method for friction-induced surface grain refinement of pure tungsten disclosed in this example specifically includes the following steps:

[0058] (1) Polish the surface of pure tungsten successively with 400-mesh, 800-mesh, 1500-mesh, and 2000-mesh silicon carbide sandpaper to remove impurities and make its surface smooth, and then fix the pure tungsten on a friction instrument;

[0059] (2) Assemble an alumina ceramic friction pair on the mechanical sensor of the friction instrument, and apply a vertical load of 30 N to the plane of the tungsten material through the friction pair;

[0060] (3) After the load application in step (2) is completed, do not heat the tungsten material with a resistance wire, so that the material is always in a room temperature environment (RT);

[0061] (4) After the operation in step (3) is completed, set the rotation speed of the tungsten material to 358 r / min and the rotation friction time to 10 min, and then start the instrument to make the tungsten material and the alumina ceramic friction pair perform rotational friction, and a grain refinement layer with nanocrystalline and gradient structures on the surface can be obtained.

[0062] Characterize the pure tungsten grain refinement layer obtained in Example 1.

[0063] Figure 2 Figure (a) is the SEM image and size distribution diagram of the grains of pure tungsten before rotational friction. It can be seen that the grain size of pure tungsten before refinement is relatively coarse, and the grain size range is between 0.6 μm and 3.4 μm, and the average grain size is 1.6 μm.

[0064] Figure 3 Figure (b) is the BSE image of the surface grains of pure tungsten after rotational friction. It can be seen that compared with before rotational friction, the grains after friction are significantly refined.

[0065] Figure 4 Figure (c) is the EBSD image and size statistical results of the surface grains of pure tungsten after rotational friction. It can be seen that the grain size range of the surface of pure tungsten after rotational friction refinement is between 0 and 1000 nm, and the average grain size is 155 nm. This confirms that the method of the present invention can achieve a significant grain refinement effect, and the average grain size is reduced by 90.3%.

[0066] Figure 5 Figure (d) is the SEM image of the grain refinement layer of pure tungsten after rotational friction. It can be seen that the refinement layer has a continuous gradient structure, and the thickness of the refinement layer is 5.0 μm.

[0067] Figure 6 Figure (e) is the Vickers hardness diagram of the surface of pure tungsten before and after rotational friction. It can be seen that the hardness of pure tungsten before friction refinement is 445 HV, and the hardness after friction refinement is 510 HV, and the hardness increases by 65 HV.

[0068] Example 2

[0069] The method for friction-induced surface grain refinement of pure tungsten disclosed in this embodiment specifically includes the following steps:

[0070] (1) Polish the surface of pure tungsten successively with 400-mesh, 800-mesh, 1500-mesh, and 2000-mesh silicon carbide sandpapers to remove impurities, and then fix the pure tungsten on a friction instrument;

[0071] (2) Assemble a silicon nitride ceramic friction pair on the mechanical sensor of the friction instrument, and apply a vertical load of 50 N to the plane of the tungsten material through the friction pair;

[0072] (3) After the load application in step (2) is completed, heat the tungsten material with a resistance wire so that the material is always in an environment of 200 °C;

[0073] (4) After the operation in step (3) is completed, set the rotation speed of the tungsten material to 600 r / min and the rotation friction time to 20 min, and then start the instrument to make the tungsten material and the silicon nitride ceramic friction pair perform rotational friction, and a grain refinement layer with nanocrystalline and gradient structures on the surface can be obtained.

[0074] Characterize the pure tungsten grain refinement layer obtained in Example 2.

[0075] Figure 7 SEM image and size distribution diagram of the grains of pure tungsten before rotational friction. It can be seen that the grain size of pure tungsten before refinement is relatively coarse, and the grain size range is between 0.6 μm and 3.0 μm, and the average grain size is 1.5 μm.

[0076] Figure 8 BSE image of the surface grains of pure tungsten after rotational friction. It can be seen that compared with before rotational friction, the grains after friction are significantly refined.

[0077] Figure 9 EBSD image and size statistical results of the surface grains of pure tungsten after rotational friction. It can be seen that the grain size range of the surface of pure tungsten after rotational friction refinement is between 0 and 1000 nm, and the average grain size is 142 nm. This confirms that the method of the present invention can achieve a significant grain refinement effect, and the average grain size is reduced by 90.5%.

[0078] Figure 10 SEM image of the grain refinement layer of pure tungsten after rotational friction. It can be seen that the refinement layer has a continuous gradient structure, and the thickness of the refinement layer is 8.1 μm.

[0079] Figure 11It is the Vickers hardness diagram of the surface of pure tungsten before and after rotational friction. It can be seen that the hardness of pure tungsten before friction refinement is 439 HV, and the hardness after friction refinement is 512 HV, with a hardness increase of 73 HV.

[0080] Example 3

[0081] The method for friction-induced surface grain refinement of pure tungsten disclosed in this example specifically includes the following steps:

[0082] (1) Polish the surface of pure tungsten successively with 400-mesh, 800-mesh, 1500-mesh, and 2000-mesh silicon carbide sandpapers to remove impurities, and then fix the pure tungsten on a friction instrument;

[0083] (2) Assemble an alumina ceramic friction pair on the mechanical sensor of the friction instrument, and apply a vertical load of 80 N to the plane of the tungsten material through the friction pair;

[0084] (3) After the load application in step (2) is completed, heat the tungsten material using a resistance wire so that the material is always in an environment of 400 °C;

[0085] (4) After the operation in step (3) is completed, set the rotation speed of the tungsten material to 490 r / min and the rotation friction time to 30 min, and then start the instrument to make the tungsten material and the alumina ceramic friction pair perform rotational friction, and a grain refinement layer with a nanocrystalline and gradient structure on the surface can be obtained.

[0086] Characterize the pure tungsten grain refinement layer obtained in Example 3.

[0087] Figure 12 It is the SEM diagram and size distribution diagram of the grains of pure tungsten before rotational friction. It can be seen that the grain size of pure tungsten before refinement is relatively coarse, and the grain size range is between 0.6 μm and 3.0 μm, with an average grain size of 1.7 μm.

[0088] Figure 13 It is the BSE image of the surface grains of pure tungsten after rotational friction. It can be seen that compared with before rotational friction, the grains after friction are significantly refined.

[0089] Figure 14 It is the EBSD image and size statistical result of the surface grains of pure tungsten after rotational friction. It can be seen that the grain size range of the surface of pure tungsten after rotational friction refinement is between 0 and 800 nm, and the average grain size is 172 nm. This confirms that the method of the present invention can achieve a significant grain refinement effect, and the average grain size is reduced by 89.9%.

[0090] Figure 15SEM image of the grain refinement layer of pure tungsten after rotational friction. It can be seen that the refinement layer has a continuous gradient structure, and the thickness of the refinement layer is 11 μm.

[0091] Figure 16 Vickers hardness diagrams of the surface of pure tungsten before and after rotational friction. It can be seen that the hardness of pure tungsten before friction refinement is 442 HV, and the hardness after friction refinement is 591 HV, with a hardness increase of 149 HV.

[0092] Example 4

[0093] The method for friction-induced surface grain refinement of pure tungsten disclosed in this example at 600 °C specifically includes the following steps:

[0094] (1) Polish the surface of pure tungsten successively with 400-mesh, 800-mesh, 1500-mesh, and 2000-mesh silicon carbide sandpapers to remove impurities, and then fix the pure tungsten on the friction instrument.

[0095] (2) Assemble a silicon nitride ceramic friction pair on the mechanical sensor of the friction instrument, and apply a vertical load of 100 N to the plane of the tungsten material through the friction pair.

[0096] (3) After the load application in step (2) is completed, heat the tungsten material using a resistance wire so that the material is always in a 600 °C environment.

[0097] (4) After the operation in step (3) is completed, set the rotation speed of the tungsten material to 200 r / min and the rotation friction time to 5 min, and then start the instrument to make the tungsten material and the silicon nitride ceramic friction pair perform rotational friction, and a grain refinement layer with a nanocrystalline and gradient structure on the surface can be obtained.

[0098] Characterize the pure tungsten grain refinement layer obtained in Example 4.

[0099] Figure 17 SEM image and size distribution diagram of the grains of pure tungsten before rotational friction. It can be seen that the grain size of pure tungsten before refinement is relatively coarse, and the grain size range is between 0.6 μm and 2.6 μm, with an average grain size of 1.7 μm.

[0100] Figure 18 BSE image of the surface grains of pure tungsten after rotational friction. It can be seen that compared with before rotational friction, the grains after friction are significantly refined.

[0101] Figure 19The EBSD images and size statistics results of the surface grains of pure tungsten after rotational friction are shown. It can be seen that the grain size range of the surface of pure tungsten after rotational friction refinement is between 0 - 1000 nm, and the average grain size is 269 nm. This confirms that the method of the present invention can achieve a significant grain refinement effect, and the average grain size is reduced by 84.2%.

[0102] Figure 20 The SEM image of the grain refinement layer of pure tungsten after rotational friction is shown. It can be seen that the refinement layer has a continuous gradient structure, and the thickness of the refinement layer is 15.7 μm.

[0103] Figure 21 The Vickers hardness maps of the surface of pure tungsten before and after rotational friction are shown. It can be seen that the hardness of pure tungsten before friction refinement is 450 HV, and the hardness after friction refinement is 550 HV, with the hardness increased by 100 HV.

[0104] Example 5

[0105] The method for friction-induced surface grain refinement of W-0.5% ZrC disclosed in this example specifically includes the following steps:

[0106] (1) The surface of W-0.5% ZrC is polished successively with 400-mesh, 800-mesh, 1500-mesh, and 2000-mesh silicon carbide sandpapers to remove impurities, and then W-0.5% ZrC is fixed on the friction instrument;

[0107] (2) An alumina ceramic friction pair is assembled on the mechanical sensor of the friction instrument, and a vertical load of 10 N is applied to the plane of W-0.5% ZrC through the friction pair;

[0108] (3) After the load application in step (2) is completed, W-0.5% ZrC is heated using a resistance wire so that the material is always in an environment of 100 °C;

[0109] (4) After the operation in step (3) is completed, the rotation speed of W-0.5% ZrC is set to 100 r / min, and the rotational friction time is 15 min. Then, the instrument is started to make W-0.5% ZrC and the alumina ceramic friction pair perform rotational friction, and a grain refinement layer with nanocrystals and a gradient structure on the surface can be obtained.

[0110] The pure tungsten grain refinement layer obtained in Example 5 is characterized.

[0111] Figure 22 The grain SEM image and size distribution map of W-0.5% ZrC before rotational friction are shown. It can be seen that the grain size of W-0.5% ZrC before refinement is relatively coarse, and the grain size range is between 0.6 μm - 3.0 μm, and the average grain size is 1.6 μm.

[0112] Figure 23 It is the BSE image of the surface grains of W-0.5% ZrC after rotational friction. It can be seen that, compared with before rotational friction, the grains after friction have been significantly refined.

[0113] Figure 24 It is the EBSD image and size statistical results of the surface grains of W-0.5% ZrC after rotational friction. It can be seen that the grain size range of the surface of W-0.5% ZrC after rotational friction refinement is between 250 - 2250 nm, and the average grain size is 830 nm. This confirms that the method of the present invention can achieve a significant grain refinement effect, and the average grain size is reduced by 48.1%.

[0114] Figure 25 It is the SEM image of the grain refinement layer of W-0.5% ZrC after rotational friction. It can be seen that the refinement layer has a continuous gradient structure, and the thickness of the refinement layer is 5.9 μm.

[0115] Figure 26 It is the Vickers hardness map of the surface of W-0.5% ZrC before and after rotational friction. It can be seen that the hardness of W-0.5% ZrC before friction refinement is 453 HV, and the hardness after friction refinement is 535 HV, with the hardness increased by 82 HV.

[0116] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation to the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A method for surface grain refinement of tungsten material based on friction induction, characterized in that: At room temperature or under heating conditions, a contact load is applied to the surface of the tungsten material by means of a friction member and the tungsten material is rotated to obtain a tungsten material with refined surface grains.

2. The method for friction-induced grain refinement of tungsten material surface according to claim 1, characterized in that: The specific steps include: (1) Grind the tungsten material to remove surface impurities, and then fix the tungsten material on the friction instrument; (2) A friction pair is assembled on the mechanical sensor of the friction instrument, and a vertical load of a certain value is applied to the plane of the tungsten material through the friction pair, so that contact pressure is generated between the friction pair and the surface of the tungsten material; (3) keeping the tungsten material at room temperature or heating the tungsten material to a set value, and controlling the temperature of the tungsten material to remain constant; (4) rotating the tungsten material obtained by the treatment in step (3) at a certain rotation speed so that the surface of the tungsten material rubs against the friction pair to obtain a tungsten material with refined surface grains.

3. The method for friction-induced grain refinement of tungsten material surface according to claim 1, characterized in that: The tungsten content in the tungsten material is ≥85%.

4. The method for friction-induced grain refinement of tungsten material surface according to claim 2, characterized in that: In step (1), the grinding method of the tungsten material is: using 400 mesh, 800 mesh, 1500 mesh and 2000 mesh silicon carbide sandpaper to grind the surface of the tungsten material in sequence to remove impurities on the surface of the tungsten material and make its surface smooth.

5. The method for friction-induced grain refinement of tungsten material surface according to claim 2, characterized in that: In step (2), the friction pair material is aluminum oxide ceramic or silicon nitride ceramic.

6. The method for friction-induced grain refinement of tungsten material surface according to claim 2, characterized in that: In step (2), the load value range is 10N-100N.

7. The method for friction-induced grain refinement of tungsten material surface according to claim 2, characterized in that: In step (3), the temperature setting range of the tungsten material is room temperature-600°C.

8. The method for friction-induced grain refinement of tungsten material surface according to claim 2, characterized in that: In step (4), the rotation speed range of the tungsten material is 100r / min-600r / min, and the friction action time range is 5min-30min.

9. A high hardness tungsten material, characterized in that: The method is prepared by any one of claims 1 to 8.

10. The high hardness tungsten material according to claim 9, characterized in that: The hardness of the tungsten material is greater than 500 HV.

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