An impact-resistant cemented carbide hexagonal top hammer, a preparation method and application thereof

Abstract

The application provides a kind of impact-resistant hard alloy six-surface top hammer and its preparation method and application.The hard alloy six-surface top hammer material includes base material and base material containing toughness particles;The base material constitutes the upper part of six-surface top hammer, and the base material containing toughness particles constitutes the lower part of six-surface top hammer.The cobalt content in the base material is 6-10wt.%, the total content of inhibitors Cr3C2 and VC is 0.2-0.5wt.%, and the balance is tungsten carbide, and the tungsten carbide grain size is 0.6-1.2μm.The cobalt content in the toughness particles is 8-15wt.%, the total content of inhibitors Cr3C2 and VC is 0.2-0.5wt.%, and the balance is tungsten carbide, and the tungsten carbide grain size is 0.6-2.0μm;The fracture toughness of the toughness particles is higher than that of the base material by 1-10MPa*m1 / 2.The impact-resistant hard alloy six-surface top hammer of the application adds toughness particles, the hardness of toughness particles is lower than that of base material, and the toughness is high, which can improve the impact resistance of the top hammer and effectively reduce the consumption of blasting hammer.

Description

Technical Field

[0001] This invention belongs to the field of cemented carbide technology, specifically relating to an impact-resistant cemented carbide six-sided hammer, its preparation method, and its application. Background Technology

[0002] Currently, the large-scale industrial production of synthetic diamonds mainly employs the high-temperature, high-pressure catalytic method (HPHT), where the synthesis of synthetic diamonds takes place within a cubic high-temperature, high-pressure chamber enclosed by six hexagonal top hammers. In the production cost of HPHT-synthesized diamonds, the costs of other auxiliary materials such as pyrophyllite, catalysts, and plugs are largely determined by the number of blocks and are essentially unchangeable. However, the consumption of the top hammers is a major variable, accounting for the highest proportion of total production costs and fluctuating significantly, directly impacting the company's profitability. Abnormal top hammer consumption is primarily caused by top hammer backfire, the root cause of which is the inability to seal properly during diamond synthesis. During backfire, the substances within the synthesis chamber, especially residual gases, gain enormous energy under the high temperature and pressure. When this energy exceeds the sealing pressure, it breaks through the pyrophyllite seal and is released with tremendous impact force, creating a loud noise and instantly striking the cemented carbide top hammers. Combined with the static high pressure during diamond synthesis, this far exceeds the top hammer's compressive strength, causing it to collapse. The main collapse hammer usually also collapses other top hammers that form the synthesis cavity with it, usually one hammer with three or five top hammers, causing huge economic losses to superhard material synthesis companies.

[0003] Chinese patent CN1154267 discloses a cemented carbide top hammer with gradients both internally and externally, as well as top and bottom, to improve the impact resistance of a six-sided top hammer. Its structural feature is that the cobalt content along the height direction of the top hammer gradually increases from 5-7.5 wt% at the top to 7-9 wt% at the bottom, while the cobalt content along the radial direction of the cross-section gradually increases from 5-7.5 wt% at the center to 7-9 wt% at the periphery. Since pressing defects often occur on the large and small bevels during top hammer pressing, these bevels are high-risk points for top hammer failure during diamond synthesis. The transition zone of the gradient structure in this patented top hammer is located on either the large or small bevel, posing a significant challenge to industrialization.

[0004] Chinese patents CN101787479A and CN105132779A disclose a network-structured cemented carbide for use in drilling and tunneling applications. The key feature is the uniform distribution of a certain number of high-hardness particles on a low-hardness cemented carbide matrix. These high-hardness, wear-resistant particles increase the wear resistance of the matrix, thereby extending the service life of the cemented carbide ball teeth during drilling and tunneling. The matrix for cemented carbide ball teeth used in drilling and tunneling often employs medium-coarse grain WC, resulting in a relatively soft matrix with good toughness. While the toughness of the high-hardness, wear-resistant particles is often lower than that of the matrix, the high-hardness, wear-resistant particles are surrounded by a continuous, high-toughness matrix, ensuring that the toughness of the network-structured cemented carbide does not significantly deteriorate. In the field of synthetic diamond synthesis, cemented carbide mandrels often employ fine-grained WC, which has high hardness but poor toughness. For example, using the network structure cemented carbide schemes in CN101787479A and CN105132779A, which add even less tough, high-hardness, wear-resistant particles, will further deteriorate the toughness of the cemented carbide mandrel, increasing its defect sensitivity and brittleness. During diamond synthesis, if a blow is made, the mandrel will be more prone to cracking under the impact, increasing the likelihood of mandrel collapse and resulting in higher wear and tear. Summary of the Invention

[0005] To address the aforementioned problems in the prior art, this invention proposes an impact-resistant cemented carbide six-sided hammer, its preparation method, and its application.

[0006] In a first aspect, the present invention proposes an impact-resistant cemented carbide six-sided hammer, the cemented carbide six-sided hammer material comprising an upper matrix material and a lower matrix material containing tough particles; the matrix material constitutes the upper part of the six-sided hammer, and the matrix material containing tough particles constitutes the lower part of the six-sided hammer.

[0007] As a specific embodiment of the present invention, the cobalt content in the matrix material is 6-10 wt%, the total content of the inhibitor Cr3C2 and VC is 0.2-0.5 wt%, and the balance is tungsten carbide, wherein the tungsten carbide grain size is 0.6-1.2 μm, preferably 0.7-0.9 μm.

[0008] In a specific embodiment of the present invention, the cobalt content in the toughening particles is 8-15 wt%; the total content of the inhibitor Cr3C2 and VC is 0.2-0.5 wt%, and the balance is tungsten carbide, wherein the tungsten carbide grain size is 0.6-2.0 μm, preferably 1.0-1.6 μm;

[0009] The fracture toughness of the tough particles is 1-10 MPa*m1 / 2 higher than that of the matrix.

[0010] As a specific embodiment of the present invention, the tough particles and the matrix are uniformly mixed to form the lower half of the six-sided top hammer cylinder, in which the weight of the tough particles accounts for 5 to 30% of the total weight of the tough particles and the matrix.

[0011] In a specific embodiment of the present invention, the height of the portion containing toughening particles is 1 to 30% of the total height of the top hammer, preferably 20 to 30%. Specifically, the upper part of the six-sided top hammer and the radial volume portion of the small inclined surface, the large inclined surface, and the upper half of the cylindrical surface are formed by the upper matrix material, while the lower part of the six-sided top hammer and the radial volume portion of the lower half of the cylindrical surface are formed by the lower matrix material containing toughening particles.

[0012] Thus, the gradient transition zone is also the transition zone of cobalt content change, as well as the transition zone of hardness and toughness. The gradient transition zone is located in the top hammer column, which helps to reduce production difficulty and production cost. The top hammer column has a simple shape, and it is not easy to generate pressing defects such as cracks and delamination during pressing. At the same time, since the matrix accounts for a high proportion on both sides of the transition zone, the continuity of the matrix is ​​not destroyed by toughness particles, so the generation of pressing defects in the gradient transition zone can be greatly reduced.

[0013] As a specific embodiment of the present invention, the impact-resistant cemented carbide six-sided hammer has a hardness range of 90.0 to 93.0 HRA and a fracture toughness range of 8 to 15 MPa*m1 / 2.

[0014] All of the above-mentioned raw materials used in this invention can be prepared in-house or purchased commercially; this invention does not impose any particular limitations on them.

[0015] Secondly, the present invention provides a method for preparing the aforementioned impact-resistant cemented carbide six-sided hammer, comprising the following steps:

[0016] S1: Prepare matrix mixture A by mixing tungsten carbide powder, cobalt powder, and inhibitor powder;

[0017] S2: Prepare tough particle mixture B by mixing tungsten carbide powder, cobalt powder, and inhibitor powder;

[0018] S3: Mix the matrix mixture A obtained in step S1 and the tough particle mixture B obtained in step S2 evenly to prepare a matrix mixture C containing tough particles.

[0019] S4: The matrix mixture A obtained in step S1 and the matrix mixture C containing tough particles obtained in step S3 are layered and loaded, and then molded to obtain a cemented carbide six-sided top hammer press blank containing local tough particles.

[0020] S5: The cemented carbide six-sided top hammer blank containing local tough particles obtained in step S4 is sintered, coarsely ground, and finely ground to obtain an impact-resistant cemented carbide six-sided top hammer.

[0021] As a specific embodiment of the present invention, in step S1, the production process conditions for preparing the matrix mixture A include: ball milling for 30 to 50 hours followed by filtration, and then spray drying, with an atomization pressure of 1.0 to 1.2 MPa and a spray tower outlet temperature of 95 to 100°C.

[0022] The mass ratio of tungsten carbide powder, cobalt powder, and inhibitor powder is (89.5–93.8):(6–10):(0.2–0.5).

[0023] As a specific embodiment of the present invention, in step S2, the production process conditions for preparing the tough particle mixture B include: ball milling for 20 to 40 hours followed by filtration, and then spray drying, with an atomization pressure of 1.0 to 1.2 MPa and a spray tower outlet temperature of 95 to 100°C.

[0024] The mass ratio of tungsten carbide powder, cobalt powder, and inhibitor powder is (84.5–91.8):(8–15):(0.2–0.5).

[0025] As a specific embodiment of the present invention, in step S3, the production process conditions for preparing the matrix mixture C containing tough particles include: weighing the matrix mixture A and the tough particle mixture B at a certain mass ratio, and mixing them using a double cone mixer for 1 to 3 hours, preferably 1 to 2 hours;

[0026] The mass ratio of the matrix mixture A to the toughening particle mixture B is (70-95):(5-30);

[0027] In a specific embodiment of the present invention, in step S4, the pressing pressure is 100-200 MPa.

[0028] As a specific embodiment of the present invention, in step S5, the sintering conditions include: a sintering temperature of 1380-1480°C, a sintering pressure of 5-10 MPa, and a holding time of 0.5-3 h.

[0029] The conditions for rough grinding and fine grinding include: rough grinding with an 80# grinding wheel and a grinding depth of 0.02mm; and fine grinding with a 240# grinding wheel and a grinding depth of 0.01mm.

[0030] The final product of the top hammer has dimensional and positional tolerances and surface roughness that conform to the national standard YS / T 503-2020.

[0031] Thirdly, the present invention provides the application of the impact-resistant cemented carbide six-sided hammer in the field of synthetic diamond synthesis.

[0032] In the diamond synthesis process, abnormal consumption of the top hammer due to breakage and collapse typically falls into two categories: collapse during pressurization, where the main collapse hammer usually causes other top hammers forming the synthesis cavity to collapse as well, usually one hammer causing three other top hammers to collapse; and collapse during overpressure, usually one hammer causing five other top hammers to collapse. The top hammer of this invention effectively reduces the abnormal consumption of the top hammer caused by breakage and collapse during pressurization, typically reducing the top hammer consumption to one hammer causing zero or one other top hammer.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] 1. The cobalt content transition zone of the impact-resistant cemented carbide six-sided top hammer of the present invention is located in the top hammer column, which helps to reduce production difficulty and production cost. The top hammer column has a simple shape, and it is not easy to produce pressing defects such as cracks and delamination during pressing. At the same time, since the matrix on both sides of the transition zone has a high proportion, the continuity of the matrix is ​​not destroyed by tough particles, so the generation of pressing defects in the gradient transition zone can be greatly reduced.

[0035] 2. Unlike traditional six-sided top hammers with added wear-resistant particles in a mesh alloy, the impact-resistant cemented carbide six-sided top hammer of this invention incorporates toughening particles. These toughening particles have lower hardness and higher toughness than the matrix material, thus improving the impact resistance of the top hammer. During use, if a backlash occurs, the lower part of the top hammer is softer and tougher, effectively placing the upper part of the high-hardness top hammer on top of a softer, tougher lower part. The impact force generated by the backlash is absorbed by the lower part of the top hammer, effectively protecting the upper part. Since the high-risk failure points during top hammer use are located on the upper part: around the top surface, the lower edge of the small inclined plane, the center line of the large inclined plane, and the side edges of the top hammer, protecting the upper part effectively prevents failure at these high-risk points, thereby effectively reducing hammer wear during backlash. Test application examples show that the top hammer of this invention can effectively reduce the wear of the top hammer during the diamond synthesis pressurization process by approximately 50%. Attached Figure Description

[0036] Figure 1a This is a schematic cross-sectional view of the impact-resistant cemented carbide six-sided hammer obtained in Embodiment 1 of the present invention;

[0037] Figure 1b Metallographic image of the upper substrate material of the impact-resistant cemented carbide six-sided hammer obtained in Embodiment 1 of the present invention;

[0038] Figure 1c Metallographic image of the matrix material containing tough particles in the lower part of the impact-resistant cemented carbide six-sided hammer obtained in Embodiment 1 of the present invention;

[0039] Figure 2 Based on Figure 1a Rockwell hardness distribution along the cross section of line AA;

[0040] Figure 3 Based on Figure 1aFracture toughness distribution along the AA line section.

[0041] Among them, 1-matrix material; 2-tough particles. Detailed Implementation

[0042] The present invention will be further described below with reference to specific embodiments, but this does not constitute any limitation on the present invention.

[0043] In various embodiments of the present invention, the hardness is obtained by the HRA Rockwell hardness test method, and the test standard is ISO3738; the fracture toughness is obtained by the Barcol indentation method, and the test standard is ISO 28079-2009.

[0044] Example 1

[0045] This embodiment provides an impact-resistant cemented carbide six-sided hammer and its preparation method, with specific details as follows:

[0046] S1: The matrix material consists of 89.5 wt% WC, 0.5 wt% Cr3C2, and 10 wt% Co by mass percentage, with WC having a grain size of 0.8 μm. It is wet-milled in a ball mill with a ball-to-material mass ratio of 5:1. Alcohol is selected as the ball milling medium, with 370 ml of alcohol added per kilogram of raw material. Paraffin is selected as the forming agent, with 20 g of paraffin added per kilogram of raw material. After ball milling for 35 hours, it is filtered and spray-dried to obtain matrix mixture A#.

[0047] S2: The tough particle material is weighed according to the mass percentage of 86.5wt% WC, 0.5wt% Cr3C2 and 13wt% Co, where the WC grain size is 1.2μm. It is ball-milled for 25h, and the other processes are the same as the matrix material preparation process to prepare tough particle mixture B#.

[0048] S3: Weigh the matrix mixture A# and the toughening particle mixture B# at a mass ratio of 8:2, and mix them in a double cone mixer for 2 hours to prepare the matrix mixture C# containing toughening particles.

[0049] S4: Layer mixture A# and mixture C#, with the filling height of mixture C# being 30% of the total filling height, and press pressure being 180MPa for molding.

[0050] S5: Finally, the impact-resistant six-sided top hammer is prepared by sintering, rough grinding, and fine grinding according to the conventional six-sided top hammer production process. The sintering temperature is 1410℃, the sintering pressure is 9MPa, and the holding time is 2h; rough grinding is carried out using an 80# grinding wheel with a grinding depth of 0.02mm; fine grinding is carried out using a 240# grinding wheel with a grinding depth of 0.01mm.

[0051] The impact-resistant cemented carbide six-sided hammer obtained in Example 1 has a shape and position tolerance and surface roughness that meet the requirements of national standard YS / T503-2020. Figure 1b The metallographic image shows the matrix material of the upper part of the hammer, which does not contain tough particles; Figure 1c The lower part of the hammer shown contains toughening particles; performance testing revealed that the upper part of the hammer has a hardness of 91.5, and the lower part has a hardness of 90.9. Figure 2 As shown; the fracture toughness is 10.8 at the top and 12.9 at the bottom, as... Figure 3 As shown in the figure; the test results are shown in Table 1.

[0052] The impact-resistant cemented carbide six-sided hammer obtained in Example 1 has a cobalt content of 10% in the upper part and 10%*0.8+13%*0.2=10.6% in the lower part; the gradient transition zone refers to the transition zone between the cobalt content of 10% and the cobalt content of 10.6%.

[0053] Example 2

[0054] This embodiment provides an impact-resistant cemented carbide six-sided hammer and its preparation method, with specific details as follows:

[0055] S1: The matrix material is weighed according to the mass percentage of 89.5WC-0.3Cr3C2-0.2VC-10Co, where the WC grain size is 0.8μm. It is wet-milled in a ball mill with a ball-to-material mass ratio of 5:1. Alcohol is selected as the ball milling medium, and 370ml of alcohol is added per kilogram of raw material. Paraffin is selected as the forming agent, and 20g of paraffin is added per kilogram of raw material. After ball milling for 35 hours, it is filtered and spray-dried to obtain matrix mixture A#.

[0056] S2: The tough particle material is weighed according to the mass percentage of 84.5WC-0.3Cr3C2-0.2VC-15Co, where the WC grain size is 0.8μm. It is ball-milled for 35h, and the other preparation processes are the same as those for the matrix material to prepare tough particle mixture B#.

[0057] S3: Weigh the matrix mixture A# and the toughening particle mixture B# at a mass ratio of 9:1, and mix them in a double cone mixer for 2 hours to prepare the matrix mixture C# containing toughening particles.

[0058] S4: Layer mixture A# and mixture C#, with the filling height of mixture C# being 30% of the total filling height, and press pressure being 180MPa for molding.

[0059] S5: Finally, the impact-resistant six-sided top hammer is prepared by sintering, rough grinding, and fine grinding according to the conventional six-sided top hammer production process. The sintering temperature is 1400℃, the sintering pressure is 9MPa, and the holding time is 1.5h; rough grinding is carried out using an 80# grinding wheel with a grinding depth of 0.02mm; fine grinding is carried out using a 240# grinding wheel with a grinding depth of 0.01mm.

[0060] The impact-resistant cemented carbide six-sided hammer obtained in Example 2 has a shape and position tolerance and roughness that meet the requirements of national standard YS / T503-2020. Its performance was tested, and the test results are shown in Table 1.

[0061] Example 3

[0062] This embodiment provides an impact-resistant cemented carbide six-sided hammer and its preparation method, with specific details as follows:

[0063] S1: The matrix material is weighed according to the mass percentage of 93.8WC-0.2VC-6Co, where the WC grain size is 1.2μm. It is wet-milled in a ball mill with a ball-to-material mass ratio of 4:1. Alcohol is selected as the ball milling medium, and 330ml of alcohol is added per kilogram of raw material. Paraffin is selected as the forming agent, and 20g of paraffin is added per kilogram of raw material. After ball milling for 32 hours, it is filtered and spray-dried to obtain matrix mixture A#.

[0064] S2: The tough particle material is weighed according to the mass percentage of 89.8WC-0.2VC-10Co, where the WC grain size is 1.2μm. It is ball-milled for 34 hours, and the other preparation processes are the same as those for the matrix material, to prepare tough particle mixture B#.

[0065] S3: Weigh the matrix mixture A# and the toughening particle mixture B# at a mass ratio of 7:3, and mix them in a double cone mixer for 2 hours to prepare the matrix mixture C# containing toughening particles.

[0066] S4: Layer mixture A# and mixture C#, with the filling height of mixture C# being 30% of the total filling height, and press pressure being 160MPa for molding.

[0067] S5: Finally, the impact-resistant six-sided top hammer is prepared by sintering, rough grinding, and fine grinding according to the conventional six-sided top hammer production process. The sintering temperature is 1450℃, the sintering pressure is 8MPa, and the holding time is 2.5h; rough grinding is carried out using an 80# grinding wheel with a grinding depth of 0.02mm; fine grinding is carried out using a 240# grinding wheel with a grinding depth of 0.01mm.

[0068] The impact-resistant cemented carbide six-sided hammer obtained in Example 3 has a shape and position tolerance and roughness that meet the requirements of national standard YS / T503-2020. Its performance was tested, and the test results are shown in Table 1.

[0069] Example 4

[0070] This embodiment provides an impact-resistant cemented carbide six-sided hammer and its preparation method, with specific details as follows:

[0071] S1: The matrix material is weighed according to the mass percentage of 91.7WC-0.3Cr3C2-8Co, where the WC grain size is 1.2μm. It is wet-milled in a ball mill with a ball-to-material mass ratio of 4:1. Alcohol is selected as the ball milling medium, and 330ml of alcohol is added per kilogram of raw material. Paraffin is selected as the forming agent, and 20g of paraffin is added per kilogram of raw material. After ball milling for 35 hours, it is filtered and spray-dried to obtain matrix mixture A#.

[0072] S2: The tough particle material is weighed according to the mass percentage of 89.7WC-0.3Cr3C2-10Co, where the WC grain size is 1.6μm. It is ball-milled for 25h, and the other preparation processes are the same as those for the matrix material to prepare tough particle mixture B#.

[0073] S3: Weigh the matrix mixture A# and the toughening particle mixture B# at a mass ratio of 8:2, and mix them in a double cone mixer for 2 hours to prepare the matrix mixture C# containing toughening particles.

[0074] S4: Layer mixture A# and mixture C#, with the filling height of mixture C# being 20% ​​of the total filling height, and press pressure being 150MPa for molding.

[0075] S5: Finally, the impact-resistant six-sided top hammer is prepared by sintering, rough grinding, and fine grinding according to the conventional six-sided top hammer production process. The sintering temperature is 1480℃, the sintering pressure is 6MPa, and the holding time is 2h; rough grinding is carried out using an 80# grinding wheel with a grinding depth of 0.02mm; fine grinding is carried out using a 240# grinding wheel with a grinding depth of 0.01mm.

[0076] The impact-resistant cemented carbide six-sided hammer obtained in Example 4 has a shape and position tolerance and roughness that meet the requirements of national standard YS / T503-2020. Its performance was tested, and the test results are shown in Table 1.

[0077] Example 5

[0078] This embodiment provides an impact-resistant cemented carbide six-sided hammer and its preparation method, with specific details as follows:

[0079] S1: The matrix material is weighed according to the mass percentage of 91.7WC-0.2Cr3C2-0.1VC-8Co, where the WC grain size is 1.0μm. It is wet-milled in a ball mill with a ball-to-material mass ratio of 4:1. Alcohol is selected as the ball milling medium, and 350ml of alcohol is added per kilogram of raw material. Paraffin is selected as the forming agent, and 20g of paraffin is added per kilogram of raw material. After ball milling for 40 hours, it is filtered and spray-dried to obtain matrix mixture A#.

[0080] S2: The tough particle material is weighed according to the mass percentage of 87.7WC-0.2Cr3C2-0.1VC-12Co, where the WC grain size is 1.2μm. It is ball-milled for 30h, and the other preparation processes are the same as those for the matrix material, to prepare tough particle mixture B#.

[0081] S3: Weigh the matrix mixture A# and the toughening particle mixture B# at a mass ratio of 8:2, and mix them in a double cone mixer for 2 hours to prepare the matrix mixture C# containing toughening particles.

[0082] S4: Layer mixture A# and mixture C#, with the filling height of mixture C# being 20% ​​of the total filling height, and press pressure being 160MPa for molding.

[0083] S5: Finally, the impact-resistant six-sided top hammer is prepared by sintering, rough grinding, and fine grinding according to the conventional six-sided top hammer production process. The sintering temperature is 1450℃, the sintering pressure is 8MPa, and the holding time is 2h; rough grinding is carried out using an 80# grinding wheel with a grinding depth of 0.02mm; fine grinding is carried out using a 240# grinding wheel with a grinding depth of 0.01mm.

[0084] The impact-resistant cemented carbide six-sided hammer obtained in Example 5 has a shape and position tolerance and roughness that meet the requirements of national standard YS / T503-2020. Its performance was tested, and the test results are shown in Table 1.

[0085] Table 1. Performance test results of the impact-resistant cemented carbide six-sided hammers prepared in Examples 1-5.

[0086]

[0087] Test case

[0088] Traditional top hammer: The entire hammer uses the same material as the top hammer in Example 1: 89.5WC-0.5Cr3C2-10Co, with WC grain size of 0.8μm. During the diamond synthesis pressurization process, abnormal backfiring occurs, and the collapsing hammer usually brings down other top hammers that form the synthesis cavity with it, typically 1 hammer bringing down 3.

[0089] The present invention relates to a top hammer; using the impact-resistant cemented carbide six-sided top hammer of Example 1, when abnormal backfiring occurs during the diamond synthesis pressurization process, because the bottom part of the top hammer contains tough particles, it can effectively absorb part of the impact force during backfiring in a timely manner, and the top hammer consumption of the collapse hammer usually becomes 1 with 0 or 1 with 1.

[0090] This test example shows that the top hammer of the present invention can effectively reduce the consumption of the top hammer by about 50% during the pressure boosting process of diamond synthesis.

[0091] In summary, the impact-resistant cemented carbide six-sided top hammer of the present invention has a gradient transition zone located in the top hammer column, which helps to reduce production difficulty and cost. The top hammer column has a simple shape, making it less prone to pressing defects such as cracks and delamination during pressing. At the same time, because the matrix accounts for a high proportion on both sides of the transition zone, the continuity of the matrix is ​​not disrupted by the toughening particles, thus significantly reducing the generation of pressing defects in the gradient transition zone.

[0092] Any numerical value mentioned in this invention, if there is only a two-unit interval between any minimum and any maximum value, includes all values ​​that increase by one unit each time from the minimum to the maximum value. For example, if the amount of a component, or the value of a process variable such as temperature, pressure, or time, is stated as 50-90, in this specification it means specifically listing values ​​such as 51-89, 52-88, ..., 69-71, and 70-71. For non-integer values, it may be appropriately considered that a unit is 0.1, 0.01, 0.001, or 0.0001. These are merely some specifically specified examples. In this application, in a similar manner, all possible combinations of numerical values ​​between the listed minimum and maximum values ​​are considered to have been disclosed.

[0093] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications with the same function.

Claims

1. A percussion hard metal hexagonal socket bit, characterized in that, The hard alloy hexagonal top hammer material includes an upper base material and a lower base material containing toughness particles; The base material constitutes an upper part of the hexagonal top hammer, and the base material containing toughness particles constitutes a lower part of the hexagonal top hammer; The upper base material contains 6-10 wt% of cobalt, 0.2-0.5 wt% of total content of inhibitors Cr3C2 and VC, and the balance of tungsten carbide, and the tungsten carbide grain size is 0.7-0.9 μm; The toughness particles contain 12-15 wt% of cobalt, 0.2-0.5 wt% of total content of inhibitors Cr3C2 and VC, and the balance of tungsten carbide, and the tungsten carbide grain size is 1.0-1.6 μm; The weight of the toughness particles in the base material containing toughness particles accounts for 5-30% of the total weight of the base material containing toughness particles; The height of the part containing toughness particles is 20-30% of the total height of the hexagonal top hammer; and the transition zone of the change in the cobalt content is located in the column part of the hexagonal top hammer. The toughness of the ductile particles is 1-10 MPa higher than the fracture toughness of the matrix m½; The preparation method of the impact-resistant hard alloy hexagonal top hammer comprises the following steps: S1: preparing base mixture A from tungsten carbide powder, cobalt powder, inhibitors Cr3C2 and VC, and using paraffin as a forming agent in the process of preparing the base mixture A; S2: preparing toughness particle mixture B from tungsten carbide powder, cobalt powder, inhibitors Cr3C2 and VC; S3: uniformly mixing the base mixture A obtained in step S1 and the toughness particle mixture B obtained in step S2 to prepare base mixture C containing toughness particles; S4: layering the base mixture A obtained in step S1 and the base mixture C containing toughness particles obtained in step S3 to prepare a hard alloy hexagonal top hammer compact containing toughness particles in a local part; S5: sintering, rough grinding and fine grinding the hard alloy hexagonal top hammer compact containing toughness particles in a local part obtained in step S4 to obtain an impact-resistant hard alloy hexagonal top hammer.

2. The impact-resistant cemented carbide hexagon socket head cap screw of claim 1, wherein The ratio of the cobalt content in the base material to the cobalt content in the toughness particles ranges from (6-10):(8-15); And / or, the ratio of the tungsten carbide grain size in the base material to the tungsten carbide grain size in the toughness particles ranges from (0.6-1.2):(0.6-2.0).

3. The impact-resistant cemented carbide hexagon socket head cap screw according to claim 1 or 2, characterized in that The weight of the toughness particles in the base material containing toughness particles accounts for 10-20% of the total weight of the base material containing toughness particles.

4. A method of manufacturing an impact-resistant cemented carbide hexagon socket spanner according to any one of claims 1-3, characterized in that, The preparation method comprises the following steps: S1: preparing base mixture A from tungsten carbide powder, cobalt powder, inhibitors Cr3C2 and VC, and using paraffin as a forming agent in the process of preparing the base mixture A; S2: preparing toughness particle mixture B from tungsten carbide powder, cobalt powder, inhibitors Cr3C2 and VC; S3: uniformly mixing the base mixture A obtained in step S1 and the toughness particle mixture B obtained in step S2 to prepare base mixture C containing toughness particles; S4: layering the base mixture A obtained in step S1 and the base mixture C containing toughness particles obtained in step S3 to prepare a hard alloy hexagonal top hammer compact containing toughness particles in a local part; S5: sintering, rough grinding and fine grinding the local hard alloy hexagonal anvil compact containing toughness particles obtained in step S4 to obtain the impact-resistant hard alloy hexagonal anvil.

5. The preparation method according to claim 4, characterized in that, In step S1, the production process conditions for preparing the base mixture A include: ball milling for 30-50 h, then filtering, and then spray drying, the atomization pressure being 1.0-1.2 MPa, and the spray tower outlet temperature being 95-100℃. And / or, the mass ratio of the tungsten carbide powder, the cobalt powder, the inhibitor Cr3C2 and VC is (89.5-93.8):(6-10):(0.2-0.5).

6. The production method according to claim 4 or 5, characterized by, In step S2, the production process conditions for preparing the toughness particle mixture B include: ball milling for 20-40 h, then filtering, and then spray drying, the atomization pressure being 1.0-1.2 MPa, and the spray tower outlet temperature being 95-100℃. And / or, the mass ratio of the tungsten carbide powder, the cobalt powder, the inhibitor Cr3C2 and VC is (84.5-91.8):(8-15):(0.2-0.5).

7. The production method according to claim 4 or 5, characterized by, In step S3, the production process conditions for preparing the base mixture C containing toughness particles include: weighing the base mixture A and the toughness particle mixture B according to a certain mass ratio, and mixing them by using a double-cone mixer, the mixing time being 1-3 h. And / or, the mass ratio of the base mixture A and the toughness particle mixture B is (70-95):(5-30).

8. The preparation method according to claim 7, characterized in that, In step S3, the production process conditions for preparing the base mixture C containing toughness particles include: weighing the base mixture A and the toughness particle mixture B according to a certain mass ratio, and mixing them by using a double-cone mixer, the mixing time being 1-2 h.

9. The production method according to claim 4 or 5, characterized by, In step S4, the pressing pressure is 100-200 MPa.

10. The production method according to claim 4 or 5, characterized by, In step S5, the sintering conditions include: the sintering temperature being 1380-1480℃, the sintering pressure being 5-10 MPa, and the holding time being 0.5-3 h. And / or, the rough grinding and fine grinding conditions include: first rough grinding, the grinding depth being 0.015-0.025 mm; and then fine grinding, the grinding depth being 0.005-0.015 mm.

11. The use of the impact-resistant hard alloy hexagonal anvil according to any one of claims 1-3 or the impact-resistant hard alloy hexagonal anvil prepared by the preparation method according to any one of claims 4-10 in the field of synthetic diamond.

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