Rock plate tool bit with high sharpness and high trimming and preparation method of rock plate tool bit

Abstract

The invention provides a high-sharpness high-trimming rock plate tool bit and a preparation method thereof, and relates to the technical field of diamond tools. Comprising the steps that S1, matrix powder is placed in a three-dimensional mixer according to the proportion to be mixed, silicon carbide is added into the formula of the matrix powder, the mixing time ranges from 50 min to 120 min, and a matrix mixture is obtained; s2, diamond particles are evenly distributed in the matrix mixture through a diamond adsorption device, then pressing is conducted under the pressure of 500 + / -50 kg / cm < 2 >, and a compact matrix structure is obtained; s3, the pressed blanks are spliced and then loaded into a multi-layer graphite mold, sintering is conducted at the high temperature, and heat preservation is conducted for a preset duration; s4, appearance treatment is conducted on the sintered tool bit, and the tool bit is welded to a base body; and S5, performing edging treatment on the tool bit by using a numerical control edging process, and then sequentially performing scraping, polishing and oil soaking treatment so as to optimize the surface quality and performance of the tool bit. By means of the scheme, the high-sharpness and high-trimming rock plate tool bit is manufactured.

Description

Technical Field

[0001] The present invention relates to the technical field of diamond tools, and in particular to a high-sharpness and high-cutting-edge rock slab cutter head and a preparation method thereof. Background Art

[0002] In the field of rock slab processing, diamond bits are widely used as key cutting tools for efficient and precise material processing. However, existing diamond bits suffer from numerous technical deficiencies in actual use, limiting further performance improvements. The diamond particles in conventional diamond bits are randomly distributed within the metal matrix. This distribution easily leads to segregation and aggregation, preventing the bits from maintaining uniform and stable performance during the cutting process, thus compromising cutting sharpness and often causing edge chipping.

[0003] Furthermore, due to the uneven distribution of diamonds within the cutter head, only approximately 40% of the diamonds are effectively involved in the cutting process, resulting in low cutting efficiency. Over time, the cutting speed gradually slows, and saw blade deflection and edge collapse intensify, seriously affecting processing quality. Furthermore, areas with concentrated diamonds are prone to polishing due to excessive wear, while diamonds in sparse areas are prone to chipping or falling off. This uneven wear pattern significantly shortens the overall life of the cutter head. Summary of the Invention

[0004] The invention discloses a method for preparing a high-sharp and high-cutting-edge rock slab cutter head, which has the effects of improving the uniformity of diamond distribution, improving cutting efficiency and cutting edge quality, and extending the service life of the cutter head.

[0005] The present invention adopts the following scheme: A method for preparing a high-sharp and high-cutting-edge rock slab cutter head, comprising: S1: The matrix powder is placed in a three-dimensional mixer and mixed according to the ratio. The formula of the matrix powder includes 45% to 50% copper powder, 10% to 15% iron powder, 15% to 20% zinc powder, 15% to 20% cobalt powder, and 3% to 5% silicon carbide in volume fraction. The mixing time is 50 minutes to 120 minutes to obtain a matrix mixture. S2: Use a diamond adsorption device to evenly distribute diamond particles in the matrix mixture, and then press it under a pressure of 500±50kg / cm2 to obtain a dense green body structure; S3: The pressed green bodies are assembled and placed into a multi-layer graphite mold, sintered at 760±50°C and kept warm for a preset time to achieve a firm bond between the matrix and the diamond particles; S4: Perform appearance processing on the sintered cutter head and weld it to the substrate; S5: The blade is sharpened using a CNC sharpening process, followed by scraping, polishing, and oiling to optimize the surface quality and performance of the blade.

[0006] Furthermore, in step S2, when arranging the diamond particles, diamond particles of 50 / 60 and 60 / 80 grit are mixed in a ratio of 6:4 in the middle of the matrix mixture to be embedded in the internal structure of the blade body, and then diamond particles of 80 / 100 grit are evenly arranged on the outside of the internal structure of the blade body to form the external structure of the blade body.

[0007] Furthermore, when arranging the diamond particles layer by layer, when one-third of the first diamond is exposed, the second diamond is connected, so that the diamond particles are arranged in an array on the internal structure and the external structure of the cutter head.

[0008] Furthermore, the addition ratio of silicon carbide is 4%.

[0009] Furthermore, in step S3, the insulation time is at least 1.5 minutes.

[0010] Furthermore, in step S4, the welding time is 4 seconds, and the welding strength is checked to be greater than 300 MPa.

[0011] The present invention also provides a rock slab cutter head, which is prepared by the above-mentioned method for preparing a high-sharp and high-cutting-edge rock slab cutter head.

[0012] Furthermore, the cutter head includes a cutter body external structure and a cutter body internal structure, and the particle size of the diamond particles arranged on the cutter body external structure is larger than the particle size of the diamond particles arranged on the cutter body internal structure.

[0013] Beneficial effects: This solution solves the problems of low cutting efficiency, poor cutting edge quality and short cutter head life caused by uneven diamond distribution in the existing technology by optimizing the matrix formula, diamond gradient distribution design and precision sintering process. It has the advantages of improving the uniformity of diamond distribution, improving cutting efficiency and cutting edge quality, and extending the service life of the cutter head. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the arrangement of diamond particles in a rock slab cutter head according to an embodiment of the present invention; DETAILED DESCRIPTION Example 1 This embodiment provides a method for preparing a high-sharp, high-cutting-edge rock slab cutter head, comprising: S1: The matrix powder is placed in a three-dimensional mixer and mixed according to the ratio. The formula of the matrix powder includes 45% to 50% copper powder, 10% to 15% iron powder, 15% to 20% zinc powder, 15% to 20% cobalt powder, and 3% to 5% silicon carbide in volume fraction. The mixing time is 50 minutes to 120 minutes to obtain a matrix mixture. S2: Use a diamond adsorption device to evenly distribute diamond particles in the matrix mixture, and then press it under a pressure of 500±50kg / cm2 to obtain a dense green body structure; S3: The pressed green bodies are assembled and placed into a multi-layer graphite mold, sintered at 760±50°C and kept warm for a preset time to achieve a firm bond between the matrix and the diamond particles; S4: Perform appearance processing on the sintered cutter head and weld it to the substrate; S5: The blade is sharpened using a CNC sharpening process, followed by scraping, polishing, and oiling to optimize the surface quality and performance of the blade.

[0015] A three-dimensional mixer is a mixing device with a multi-dimensional motion trajectory. Specifically, it can use a container with planetary agitators, which achieves three-dimensional spatial diffusion of powders through a combination of rotation and revolution. The copper, iron, zinc, and cobalt powders in the matrix powder are simple powders.

[0016] After the matrix materials are precisely proportioned, they are fully mixed in a three-dimensional mixer, for example, by adjusting the mixing time to ensure uniform distribution of the components. After the mixture and diamond particles are evenly distributed by a dedicated distribution device, a green body structure with a predetermined density is formed under a set pressure. During the sintering process, the metal powder undergoes diffusion and alloying reactions, for example, a copper-based matrix forms a metallurgical bond with the diamond surface. In one embodiment, the holding time can be set to 1.5 minutes, at which time the metal elements in the matrix powder have been fully diffused to form a continuous network structure that wraps the diamond particles, while the silicon carbide additive improves the bonding interface strength through solid solution strengthening.

[0017] This solution effectively improves the uniformity of diamond distribution by optimizing the matrix material system and mixing process. Increasing the pressing strength facilitates the formation of a denser matrix structure, while increasing the temperature enhances the matrix's ability to encapsulate diamonds. This achieves an orderly arrangement of diamond particles within the matrix, increasing the proportion of diamonds effectively participating in the cutting process. The evenly distributed matrix material effectively suppresses stress concentration during the cutting process, reducing the risk of saw blade deflection. The optimized sintering process strengthens the bond between the matrix and diamonds, extending the life of the cutter head. The dense green body structure enhances the overall rigidity of the cutter head, ensuring a stable cutting path.

[0018] In a preferred embodiment, it is further proposed that when arranging the diamond particles, diamond particles with a grit size of 50 / 60 and 60 / 80 are mixed in a ratio of 6:4 in the middle of the matrix mixture to be embedded in the internal structure of the blade body, and then diamond particles with a grit size of 80 / 100 are evenly arranged on the outside of the internal structure of the blade body to form the external structure of the blade body.

[0019] The mixing of 50 / 60 and 60 / 80 grit diamond particles refers to combining diamonds of two different particle size ranges in a proportional manner. Specifically, mechanical vibration screening can be used to achieve uniform mixing of the two particles, for example, by setting the screening conditions to a vibration frequency of 20-30 Hz and an amplitude of 2-3 mm. The arrangement of 80 / 100 grit diamond particles on the outside of the blade body refers to covering the blade surface with finer diamond particles. Specifically, existing vacuum adsorption devices can be used to achieve directional particle arrangement, for example, by adjusting the adsorption pressure to 0.5-0.8 MPa and the feeding speed to 10 mm / s to achieve a densely packed particle layer.

[0020] When embedding mixed-grain diamonds in the middle layer of the matrix mixture, the vibration screening parameters are controlled to form an interlaced support structure with 50 / 60 and 60 / 80 particles, in which the 50 / 60 particles provide basic support strength, and the 60 / 80 particles fill the gaps to increase the structural density. When arranging 80 / 100-grain diamonds on the outside of the blade body, a gradient pressure pressing process is used to make the fine particles fit tightly to the middle layer, forming a dense and uniform cutting surface. Through layer-by-layer arrangement, the coarse particles in the middle layer and the fine particles on the outside form a gradient transition structure with mechanical properties. The combination of different particle sizes improves the continuity of the diamonds. Coarse-grained diamonds can improve cutting performance, while fine-grained diamonds can take into account better cutting edge quality. The combination has good cutting speed and cutting edge performance.

[0021] Compared with the random distribution of particles of a single particle size, which leads to the easy shedding of particles in the stress concentration area during the cutting process, this solution arranges particles of different particle sizes in layers, so that the coarse particles in the middle layer bear the main cutting load, and the fine particles on the outside maintain the flatness of the cutting surface, thereby avoiding the problem of local stress imbalance caused by particle aggregation. It solves the problems of low cutting efficiency and edge collapse caused by uneven distribution of diamond particles. The combination of coarse particles in the middle layer enhances the impact resistance of the internal structure of the blade body, and the fine particle layer on the outside effectively reduces the roughness of the cutting surface. The synergistic effect of the two enables the cutter head to maintain a stable cutting depth and trajectory accuracy during the cutting process.

[0022] In this embodiment, when arranging the diamond particles layer by layer, when the first diamond is exposed by one-third, the second diamond is connected, so that the diamond particles are arranged in an array on the internal and external structures of the cutter head. Arranging diamond particles layer by layer refers to arranging diamond particles of different particle sizes in different areas of the cutter body in a layered manner. Specifically, a mechanical positioning device can be used to achieve layered positioning, and local aggregation can be avoided by controlling the distance between particles. Among them, exposing one-third refers to the exposure height of the diamond particles in the matrix mixture, which can be achieved by adjusting the pressing depth so that the particles maintain an effective cutting surface while avoiding excessive protrusion. Among them, connecting the second diamond refers to forming a continuous cutting surface between adjacent particles, which can be achieved by a staggered arrangement method, and the stability of the next particle is maintained by the support of the previous particle. Among them, array arrangement refers to the diamond particles forming a regular geometric arrangement at a preset spacing.

[0023] During the cutting head pressing process, when the first diamond particle is pressed into the matrix mixture to a depth of two-thirds, the adjacent second particle is placed laterally. This repeated process creates a staggered diamond particle structure within the blade, with each layer maintaining a consistent exposed height. Within the blade's exterior, the spacing between particles is further reduced, creating a denser cutting unit. This arrangement ensures that the diamond particles participate in the cutting process sequentially, preventing stress concentration caused by multiple particles simultaneously contacting the workpiece surface. By controlling the exposed height and spacing of the particles, the diamond particles form an orderly arrangement within the matrix, effectively eliminating particle accumulation. During cutting, each diamond particle participates in the cutting process in the predetermined order, avoiding fluctuations in cutting resistance caused by uneven particle distribution. This orderly distribution of diamond particles within the blade ensures uniform cutting force distribution to each particle, minimizing particle shedding caused by local overload. The support provided by adjacent particles enhances overall structural stability, maintaining the integrity of the blade's geometry during high-speed cutting. Regularly arranged particles form a continuous cutting track, effectively reducing the roughness of the cutting surface and inhibiting the occurrence of edge collapse defects.

[0024] The present application further proposes a method for preparing a high-sharp and high-cutting-edge rock slab cutter head, which includes adding silicon carbide to the matrix powder, and the addition ratio of silicon carbide is 4%. The addition ratio of silicon carbide refers to the volume fraction of silicon carbide in the matrix powder, which can be achieved by adjusting the amount of silicon carbide fed during the mixing process. When this ratio is controlled at 4%, it can effectively enhance the hardness of the matrix while avoiding the problem of excessive addition leading to a decrease in the bonding strength between the matrix and diamond particles during the sintering process. As a hard phase additive, silicon carbide forms a dispersion-strengthened structure with the metal matrix during the sintering process, thereby improving the overall wear resistance of the cutter head.

[0025] During the matrix mixture preparation stage, silicon carbide is fed into a three-dimensional mixer along with copper, iron, zinc, and cobalt powders in a proportional volume ratio. When the silicon carbide content reaches 4%, its distribution density within the matrix is sufficient to form a continuous reinforcement network without excessively hindering the diffusion and bonding of the metal powders. During the subsequent sintering process, the silicon carbide particles react with the metal matrix to form a stable composite structure. This structure effectively suppresses plastic deformation of the matrix during cutting and maintains the support stability of the diamond particles.

[0026] By limiting the silicon carbide addition to 4%, this solution not only ensures the diamond-grinding strength of the matrix, but also creates a high-hardness composite matrix through the synergistic effect of silicon carbide and metal, solving the problem of reduced cutting edge quality caused by matrix deformation during cutting. This solution also achieves an optimized balance between the hardness and toughness of the cutter head matrix, effectively maintaining a stable arrangement of diamond particles during cutting and preventing particle loss due to matrix softening. Furthermore, the strengthening effect of silicon carbide ensures that the cutter head maintains its structural integrity even under high-temperature cutting conditions, avoiding cutting path deviation caused by thermal deformation.

[0027] In step S4, the welding time is set to 4 seconds, and the weld strength is verified to be greater than 300 MPa. The welding time refers to the duration of the welding process between the blade tip and the substrate. This can be controlled using high-frequency induction welding equipment, precisely controlling the heating time to prevent structural changes in the substrate material due to overheating. The weld strength refers to the maximum load per unit area of the weld interface. This can be achieved by performing a tensile test using a universal material testing machine, with a set strength threshold ensuring a secure bond between the blade tip and the substrate.

[0028] Specifically, during the welding process, the cutter head and substrate are positioned in a fixture, and a high-frequency induction coil then locally heats the weld area. The welding time is set to 4 seconds, within which the matrix material and the substrate surface reach a molten state and form a metallurgical bond. After welding is completed, the weld interface is sampled and inspected through tensile testing to verify that its strength reaches 300 MPa or above. Products that do not meet the standard are rejected.

[0029] This solution optimizes the relationship between welding time and strength, minimizing the heat-affected zone while maintaining joint strength, thus preventing degradation of the cutter head due to thermal damage. This effectively addresses the issue of cutter head detachment caused by insufficient weld strength, ensuring a stable connection between the cutter head and the substrate even under high-speed cutting conditions, thereby extending the overall tool life and improving cutting safety.

[0030] Example 2 This embodiment provides a method for preparing a high-sharp, high-cutting-edge rock slab cutter head, comprising: S1: The carcass powder is mixed in a three-dimensional mixer according to the formula: 48% copper powder, 12% iron powder, 17% zinc powder, 19% cobalt powder, and 4% silicon carbide. These powders are mixed in the three-dimensional mixer for 90 minutes to obtain the carcass mixture. S2: Using a diamond adsorption device, diamond particles are evenly distributed throughout the matrix mixture. In the center of the matrix mixture, diamond particles with grit sizes of 50 / 60 and 60 / 80 are mixed in a 6:4 ratio to form the internal structure of the blade. Next, diamond particles with grit sizes of 80 / 100 are evenly distributed around the outside to form the external structure. As the diamond particles are laid out layer by layer, when one-third of the first diamond is exposed, the second diamond is added to form an array.

[0031] S3: Pressing is performed at a pressure of 500 kg / cm2 to obtain a dense green body structure. The pressed green bodies are then assembled and placed into a multi-layer graphite mold. Sintering is performed at 760°C and held for 1.5 minutes to achieve a firm bond between the matrix and the diamond particles.

[0032] S4: Perform appearance treatment on the sintered cutter head and weld it to the substrate. The welding time is 4 seconds, and the welding strength is ensured to be greater than 300MPa. S5: The blade is sharpened using a CNC sharpening process, followed by scraping, polishing, and oiling to optimize the surface quality and performance of the blade.

[0033] The rock slab cutter head prepared by this method has evenly distributed diamond particles and reasonable internal and external structures, which can maintain stable cutting performance, improve cutting efficiency, and extend service life.

[0034] In order to verify the effect of silicon carbide addition on the performance of the cutter head, a set of experiments was set up here. Specifically, based on the formula of the matrix mixture of this embodiment, the content of copper powder, iron powder, zinc powder, and cobalt powder remains roughly unchanged, and the other steps and parameters are the same. The difference is that the addition amount of silicon carbide is 0%, 3%, 4%, and 5%, respectively. When adjusting the content of silicon carbide, the content of copper powder, iron powder, zinc powder, and cobalt powder can be adjusted accordingly in proportion to make the total volume fraction in each group of experiments the same. Experiments were conducted on the cutting current and power of the prepared cutter head. The comparison of the cutting current obtained is shown in Table 1, and the comparison of the power obtained is shown in Table 2: Table 1

[0035] Table 2

[0036] Note: 1. Comparison benchmark: Cutting head without silicon carbide added (100%); 2. Experimental conditions: cutting speed 2 mm / s, rock plate thickness 10 mm (material: granite).

[0037] The above experimental data shows that the addition of silicon carbide results in lower cutting current and power than without it, with both levels reaching their lowest when the silicon carbide addition is 4%. Under the same operating conditions and at the same cutting efficiency, lower power consumption results in less electricity, and lower cutting current also results in better sharpness. Therefore, a 4% silicon carbide addition results in superior performance for rock cutter heads.

[0038] Example 3 Combine Figure 1 This embodiment provides a rock slab cutter head, which is manufactured by the method for manufacturing a high-sharp, high-cutting-edge rock slab cutter head. The cutter head includes an external cutter body structure and an internal cutter body structure, and the diamond particles arranged on the external cutter body structure have a larger particle size than the diamond particles arranged on the internal cutter body structure.

[0039] Diamond particles are evenly and orderly distributed throughout the cutter head. The outer layer of fine particles continuously participates in the cutting process, while the inner coarse particles provide structural support, and the matrix binder maintains a stable form even at high temperatures. This structure effectively avoids deflection, edge collapse, and abnormal wear caused by uneven particle distribution during cutting, ensuring the cutter head maintains high sharpness while extending its service life.

[0040] Here, the external structure of the blade refers to the surface layer area where the blade head is in direct contact with the cutting object. Specifically, it can be realized by using a composite layer formed by pressing diamond particles and a matrix mixture. This structure plays the main role in cutting. Among them, the internal structure of the blade refers to the support layer area in the blade head located below the external structure. Specifically, it can be formed by layering and pressing diamond particles of different particle sizes with a matrix mixture. This structure is used to enhance the overall strength of the blade head. Among them, the difference in the particle size of the diamond particles refers to the use of finer particles in the external structure to take into account better cutting quality, and the use of coarser particles in the internal structure to improve cutting performance. Through particle size grading and structural stratification, the diamond particles form an orderly gradient distribution inside the blade head, which not only avoids stress concentration caused by particle aggregation, but also prevents insufficient support caused by particle loss, thereby improving cutting stability.

[0041] In the above-mentioned embodiment, innovative formulations and processes precisely control the concentration and distribution of diamonds, ensuring a uniform and orderly arrangement within the cutter head. This significantly improves the effective utilization of diamonds, reduces cutting resistance, and enhances drainage, ensuring a smooth and unimpeded cutting process. By optimizing the matrix binder formula and incorporating a high-performance silicon carbide additive, the cutter head's hardness and thermal stability are significantly enhanced, minimizing wear and deformation during cutting, ensuring a precise cutting path and smooth, even edges. A scientifically designed cutter head structure, combined with advanced manufacturing processes, enhances overall strength and impact resistance, maintaining stable cutting performance even under complex working conditions. This results in cutting efficiency improvements of over 40% compared to conventional cutter heads.

[0042] The cutter head prepared by this solution has excellent stability and wear resistance. By optimizing the matrix binder formula and adding silicon carbide high-performance additives, the hardness and thermal stability of the cutter head are significantly enhanced. The wear and deformation of the cutter head can be effectively suppressed during cutting, ensuring a precise cutting trajectory, smooth and flat cutting edges, and no defects such as chipping and burrs, meeting the stringent requirements of high-end rock plate processing. It solves the problem of trajectory deviation caused by matrix softening during diamond cutter head cutting, avoids cutting edge chipping defects caused by stress concentration, and improves the roughness of the cutting surface. At the same time, by optimizing the diamond distribution pattern, the load impact of a single diamond during cutting is reduced, extending the service life of the cutter head. In addition, the strengthened matrix binder effectively suppresses abnormal diamond shedding and maintains the stability of the cutting process.

[0043] It should be understood that the above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention.

[0044] The above description of the drawings used in the implementation manner only shows certain embodiments of the present invention and should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without making any creative efforts.

Claims

1. A method for preparing a high-sharp and high-cutting-edge rock slab cutter head, characterized in that: include: S1: The matrix powder is placed in a three-dimensional mixer and mixed according to the ratio. The formula of the matrix powder includes 45% to 50% copper powder, 10% to 15% iron powder, 15% to 20% zinc powder, 15% to 20% cobalt powder, and 3% to 5% silicon carbide in volume fraction. The mixing time is 50 minutes to 120 minutes to obtain a matrix mixture. S2: Use a diamond adsorption device to evenly distribute diamond particles in the matrix mixture, and then press it under a pressure of 500±50 kg / cm2 to obtain a dense green body structure; S3: The pressed green bodies are assembled and placed into a multi-layer graphite mold, sintered at 760±50°C and kept warm for a preset time to achieve a firm bond between the matrix and the diamond particles; S4: Perform appearance processing on the sintered cutter head and weld it to the substrate; S5: The blade is sharpened using a CNC sharpening process, followed by scraping, polishing, and oiling to optimize the surface quality and performance of the blade.

2. The method for preparing a high-sharp and high-cutting-edge rock slab cutter head according to claim 1, characterized in that: In step S2, when arranging the diamond particles, diamond particles of 50 / 60 and 60 / 80 grits are mixed in a ratio of 6:4 in the middle of the matrix mixture to be embedded in the internal structure of the blade body, and then diamond particles of 80 / 100 grits are evenly arranged on the outside of the internal structure of the blade body to form the external structure of the blade body.

3. The method for preparing a high-sharp and high-cutting-edge rock slab cutter head according to claim 2, characterized in that: When arranging the diamond particles layer by layer, when one-third of the first diamond is exposed, the second diamond is connected, so that the diamond particles are arranged in an array on the internal and external structures of the cutter head.

4. The method for preparing a high-sharp and high-cutting-edge rock slab cutter head according to claim 1, characterized in that: The addition ratio of the silicon carbide is 4%.

5. The method for preparing a high-sharp and high-cutting-edge rock slab cutter head according to claim 1, characterized in that: In step S3, the holding time is at least 1.5 minutes.

6. The method for preparing a high-sharp and high-cutting-edge rock slab cutter head according to claim 1, characterized in that: In step S4, the welding time is 4 seconds, and the welding strength is checked to be greater than 300 MPa.

7. A rock slab cutter head, characterized in that: It is prepared by the preparation method of the high-sharp and high-cutting-edge rock slab blade as described in any one of claims 1-6.

8. The rock slab cutter head according to claim 7, characterized in that: The cutter head comprises a cutter body external structure and a cutter body internal structure, and the particle size of the diamond particles arranged on the cutter body external structure is larger than the particle size of the diamond particles arranged on the cutter body internal structure.

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