Composite diamond saw blade with high thermal stability and preparation method thereof

Abstract

The invention relates to the technical field of diamond saw blade preparation, and discloses a composite diamond saw blade with high thermal stability and a preparation method thereof.The composite diamond saw blade comprises a metal tool bit and a steel matrix, and the metal tool bit is prepared from, by mass, 40-45 parts of cobalt powder; 43 to 48 parts of iron powder; 6-8 parts of copper powder; 3-5 parts of silver powder; 2 to 3 parts of ZnAl-LDH (layered double hydroxide); 1 to 2 parts of Ti3SiC2 powder; 0.8 to 1.2 parts of B4C nano powder; 0.8 to 1.2 parts of niobium powder; 1-2 parts of a molding aid; the preparation method comprises the following steps: raw material weighing, ball-milling powder preparation, mixing and granulation, cold press molding, plasma-assisted hot pressed sintering, and cutter head cutting and processing. According to the diamond saw blade composite material, a multi-metal system and a high-performance functional ceramic composite material are adopted, a brand-new diamond saw blade composite material is made, and through reasonable component design and mutual cooperation, the hardness and wear resistance are improved.

Description

Technical Field

[0001] The present application relates to the technical field of diamond saw blade preparation, and specifically to a composite diamond saw blade with high thermal stability and a preparation method thereof. Background Art

[0002] In the field of diamond tools, diamond saw blades are the most commonly used tool for cutting hard and brittle materials. They are widely used in cutting high-hardness materials such as granite, marble, ceramics, and concrete. Diamond particles themselves possess extremely high hardness and wear resistance, but their actual cutting efficiency and lifespan depend largely on their ability to retain the particles and their synergy with the metal substrate.

[0003] Existing diamond saw blades are often manufactured using iron-, copper-, or cobalt-based powders as a binder, using hot pressing or conventional sintering processes. These blades have a relatively mature structure and low manufacturing costs, making them suitable for low- to medium-speed cutting conditions. They are particularly widely used in the processing of architectural and decorative materials and general hard rock cutting.

[0004] However, the existing preparation technology of diamond saw blades uses long-term high-temperature cutting, which is prone to stress concentration due to uneven thermal expansion, leading to crack expansion or blade breakage. The hard particles are unevenly distributed in the matrix and have weak bonding with the metal interface, and often fall off during the cutting process, which not only affects the life of the blade, but also causes fluctuations in the quality of the cut section. In addition, the conventional sintering process has limitations in temperature control and structural density, and the material is prone to uneven sintering and high porosity. Therefore, the present invention provides a composite diamond saw blade with high thermal stability and a preparation method thereof to address the shortcomings of the prior art. Summary of the Invention

[0005] In response to the shortcomings of the existing technology, the purpose of this application is to provide a composite diamond saw blade with high thermal stability and a preparation method thereof, which solves the problems of poor heat resistance, insufficient structural density, low crack resistance and uneven distribution of strengthening components of diamond saw blade materials prepared by existing preparation technologies.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: a composite diamond saw blade with high thermal stability, comprising a metal blade head and a steel substrate, wherein the metal blade head is composed of the following raw material components in parts by mass: Cobalt powder: 40-45 parts; Iron powder: 43-48 parts; Copper powder: 6-8 parts; Silver powder: 3-5 parts; ZnAl-LDH: 2-3 parts; Ti3SiC2 powder: 1-2 parts; B4C nano powder: 0.8-1.2 parts; Niobium powder: 0.8-1.2 parts; Molding aid: 1-2 parts.

[0007] Cobalt powder: 40-45 parts. As the primary binder metal, cobalt powder exhibits excellent wettability and sintering activity, effectively encapsulating diamond particles and other functional fillers, forming a continuous, dense metal network during sintering. Cobalt possesses high heat and wear resistance, significantly improving the high-temperature stability and impact resistance of the saw blade. At high temperatures, cobalt forms a stable cobalt carbide phase at the diamond interface, enhancing diamond retention. Its high thermal conductivity and diffusion rate promote close bonding between the powders, forming a dense metal matrix.

[0008] Iron powder: 43-48 parts. Iron powder is the main reinforcing phase with low cost and high strength. It participates in the construction of the metal skeleton structure of the cutter head. Iron can form a solid solution with cobalt during sintering, improving the overall strength and wear resistance, and has good adhesion and heat treatment responsiveness. The addition of iron can adjust the hardness and toughness balance of the sintered phase, while reducing the thermal expansion coefficient of the material, which helps to control the thermal stress deformation of the metal cutter head during operation; in the coexistence state with cobalt, iron can also improve the fatigue resistance of the cutter head.

[0009] Copper powder: 6-8 parts. Copper powder acts as a secondary lubricant and thermal conductor, forming a multiphase structure with iron and cobalt during sintering, improving overall thermal conductivity and processing performance. Copper remains in a liquid phase during sintering, which promotes densification. Copper melts at relatively low temperatures, resulting in liquid-phase sintering, improving sintering efficiency and microstructure density. Furthermore, copper-rich regions act as stress buffers and crack passivation, enhancing the tool head's resistance to chipping.

[0010] Silver powder: 3-5 parts. As a rare metal additive, silver powder has excellent thermal conductivity and lubricity. It can promote the formation of sintering neck during powder sintering and improve the high-temperature oxidation resistance of the cutter head. Silver can partially diffuse to the metal interface during sintering, reducing interfacial tension and increasing bonding strength. Its chemical stability helps improve the thermal stability and oxidation resistance of the cutter head in high-load cutting and extend its service life.

[0011] ZnAl-LDH: 2-3 parts. ZnAl-LDH is a functional filler with a layered structure. It decomposes thermally during the sintering process to produce ZnO and Al2O3. These oxides are distributed in the metal matrix as dispersed phases, significantly improving its wear resistance and structural stability. The decomposition products of ZnAl-LDH can precipitate at the sintering temperature stage, inhibiting grain growth and forming a reinforced particle dispersed phase, improving the metal interface bonding quality, and enhancing the overall wear resistance and thermal stability.

[0012] Ti3SiC2 powder: 1-2 parts. Ti3SiC2 is a layered ceramic conductive phase that possesses the dual properties of metal and ceramic, including high conductivity, high toughness, and excellent thermal stability. Its inclusion improves the current response during the sintering process and the overall crack resistance of the composite material. The layered structure of Ti3SiC2 creates dispersed microcracks within the tool head, effectively alleviating stress concentration and inhibiting crack propagation. It also exhibits excellent electrothermal responsiveness, enhancing plasma sintering efficiency. It forms a good interface with the metal powder, enhancing thermal stability and structural integrity.

[0013] B4C nanopowder: 0.8-1.2 parts. B4C is an ultra-hard ceramic material. As a reinforcing filler, it can significantly improve the wear resistance and hot hardness of the cutter head. Its nano-particle size distribution enables it to be more evenly dispersed in the metal matrix and form a microscopic multiphase structure with other components. The high hardness of B4C can effectively improve the cutting performance of the cutter head. Its β-crystal structure is stable and combines well with the metal matrix, reducing weak grain boundaries. Its particles can hinder the crack propagation path, improve the overall fracture resistance, and have a certain self-lubricating property, which is beneficial to prolonging the cutting life.

[0014] Niobium powder: 0.8-1.2 parts. Niobium powder is a rare, refractory metal. Adding a small amount can enhance the high-temperature strength and microstructural stability of the tool bit. Niobium also participates in solid solution strengthening, improving the high-temperature plasticity of the metal powder. During the sintering process, niobium easily forms fine Nb-C and Nb-O dispersed phases, which are distributed at grain boundaries or within the grains, hindering dislocation movement and grain growth. Its high melting point improves the thermal stability of the tool bit in high-temperature cutting environments, enhancing its reliability.

[0015] Molding aids: 1-2 parts. Molding aids are used to improve powder fluidity and formability. Commonly used additives such as ethyl cellulose, polyvinyl alcohol or zinc stearate can improve the powder compaction rate and molding strength during the molding process. Molding aids can coat powder particles to form a lubricating layer, improve pressing efficiency and reduce mold wear; additives can decompose and volatilize during the subsequent sintering process to avoid sintering residues and ensure sintering density and component purity.

[0016] Preferably, the ZnAl-LDH is zinc aluminum double hydroxide, the intercalation anion of the zinc aluminum double hydroxide is selected from carbonate, nitrate or chloride, the molar ratio of Zn to Al of the zinc aluminum double hydroxide is 2:1, and the particle size distribution is 100-300 nm.

[0017] Preferably, the Ti3SiC2 is a ceramic conductive phase with a hexagonal crystal structure, a particle size of 200-500 nm, and a purity greater than 98%.

[0018] Preferably, the B4C nanopowder is β-crystalline boron carbide with a particle size of 50-100 nm and an equiaxed distribution, and the molding aid is selected from ethyl cellulose, polyvinyl alcohol or zinc stearate.

[0019] Also provided is a method for preparing a composite diamond saw blade with high thermal stability, comprising the following steps: S1. Weigh the raw materials of the metal cutting head in a preset ratio, including cobalt powder, iron powder, copper powder, silver powder, ZnAl-LDH, Ti3SiC2 powder, B4C nanopowder, niobium powder and forming additives; S2, mixing Ti3SiC2, B4C and niobium powder with copper powder and ball milling to form a functional coated composite powder; S3, mixing the functional coated composite powder with cobalt powder, iron powder, silver powder and B4C nanopowder, adding a molding aid, and then forming the metal powder and functional component premix into spherical or irregular particles with a particle size of 80-150 μm; S4, cold pressing the spherical or irregular particles under a pressure of 80 MPa to obtain a green blank; S5. The blank is sintered by plasma-assisted hot pressing under vacuum conditions. First, it is heated to 450°C and kept warm for 10 minutes. Then, the temperature is raised to 680-700°C. A pressure of 15 MPa is applied and kept warm for 15 minutes. Then, the blank is cooled to obtain a dense tool head.

[0020] In step S1, the raw material components of the metal cutting head are precisely weighed in proportion. All raw materials must be of high purity and appropriate particle size to ensure consistency and controllability during subsequent ball milling, mixing, and sintering. A microscopic multiphase structure is synergistically constructed by combining the metal binder phase (cobalt, iron, copper, and silver) with the functional ceramic phase (Ti3SiC2, B4C, ZnAl-LDH, and Nb). Cobalt and iron provide strength and thermal stability, copper and silver enhance wettability and thermal conductivity, and dispersion-strengthened components such as ZnAl-LDH and niobium enhance high-temperature performance and wear resistance. Pre-set ratios ensure balanced performance in the final cutting head.

[0021] In step S2, the ceramic reinforcement component is premixed with copper powder and wet-milled in anhydrous ethanol using zirconium oxide balls as the milling medium. The milling time is 1.5-2.5 hours, and the rotation speed is controlled at 250-350 rpm. After the ball milling is completed, the slurry is vacuum-dried at 60-80°C to obtain a composite functional powder with a uniform surface copper coating. During the ball milling process, the copper powder can physically coat the B4C, Ti3SiC2, and Nb powders to form a core-shell structure. This improves the wettability of the ceramic particles and the metal phase during subsequent sintering, promotes the formation of a transition zone at the heterogeneous interface, and enhances the stability of the microstructure.

[0022] In step S3, the obtained functionally coated composite powder is thoroughly mixed with cobalt powder, iron powder, silver powder, and the remaining B4C nanopowder, and 1-2 parts by mass of polyvinyl alcohol or zinc stearate is added as a molding aid. Spherical or irregular particles with a particle size distribution of 80-150 μm are then prepared through spray drying or mechanical compression granulation. The molding aid enhances the cohesiveness and fluidity of the powder during mixing, ensuring stable subsequent molding. The spray drying process forms highly uniform particles from the mixed powder, improving compaction and consistency in the subsequent sintering reaction. Proper control of the particle size distribution promotes close packing between particles and reduces porosity.

[0023] For step S4, the prepared particles are filled into a mold, and a unidirectional pressing pressure of 80 MPa is applied and maintained for 30-60 seconds to obtain a green blank with a dense structure and complete edges. The particles can be sieved before pressing to ensure that the particle size is within the range of 80-150 μm. Cold pressing improves the strength of the blank and establishes the basic geometric shape by mechanically compacting the gaps between the particles. The pressure of 80 MPa can ensure that the internal particles are fully in contact, providing a uniform organizational foundation for subsequent densification sintering. The green blank is strong enough to withstand subsequent handling and loading without cracks or defects.

[0024] For step S5, the green blank is placed in a plasma-assisted hot pressing system and initially heated to 450°C to decompose the molding additives and ZnAl-LDH. It is then heated to 690°C and a pressure of 15 MPa is applied. After maintaining this temperature for 15 minutes, it is naturally cooled to obtain a metal tool head with a dense structure and uniform organization. At 450°C, ZnAl-LDH is decomposed into ZnO and Al2O3, forming a dispersed strengthening phase in the metal grain boundary; 680–700°C is a low-temperature and high-efficiency sintering zone, where plasma-induced current pulses promote particle interface migration and bonding to form a fine metal skeleton structure. The Ti3SiC2 and B4C reinforcement phases effectively hinder grain growth and improve organizational strength.

[0025] Preferably, the mixing of Ti3SiC2, B4C and niobium powder with copper powder and ball milling comprises the following steps: Pretreatment is performed by wet ball milling, wherein the ball milling medium is zirconia ceramic balls and anhydrous ethanol is used as the solvent; The ball milling time is set to 1.5-2.5 hours, the ball milling speed is controlled at 250-350 rpm, and the ball-to-material ratio is controlled at 10:1-15:1 to obtain a composite coated powder; The composite coated powder after ball milling is vacuum dried at a temperature of 60-80° C. for 1-2 hours.

[0026] Preferably, the step of preparing the premix of metal powder and functional components into spherical or irregular particles with a particle size of 80-150 μm comprises the following steps: The spherical or irregular particles with a particle size of 80-150 μm are prepared by spray drying granulation technology or mechanical compression granulation method; Before the granulation, 1-2 parts by mass of a molding aid is added, the spray drying temperature is set to 160-180°C, and the nozzle diameter is 0.5-1.0mm; The particles are sintered by plasma hot pressing to form a dense cutting head, which is finally fixed to the steel substrate by high-frequency induction welding. The welding temperature is controlled at 700-750°C and the welding time is 10-12 seconds.

[0027] Preferably, the step of obtaining the green blank comprises the following steps: The ball-milled composite coated powder is mixed evenly with cobalt powder, iron powder, silver powder and B4C nanopowder, and then pressed into shape using a dry cold pressing process under a pressure of 80 MPa. The molding time is controlled within 30-60 seconds. The mixed powder is pre-vibrated and sieved before pressing to control the particle size between 80-150 μm to obtain a uniformly filled green blank structure; Through plasma-assisted hot pressing sintering, ZnAl-LDH is heated to 450℃ and decomposed into ZnO and Al2O3, which are distributed at the metal matrix grain boundaries.

[0028] Preferably, the plasma-assisted hot pressing sintering comprises the following steps: Densification is achieved by plasma-assisted hot pressing sintering, with a pulse current frequency of 5-10 Hz and a current density of 8-12 A / cm 2 ; The plasma field generates directional ion migration inside the material, causing the binder metal phase to diffuse and bond; Apply an axial pressure of 15 MPa and keep the temperature at 680-700°C for 15 minutes to form a dense metal matrix.

[0029] Preferably, the process of making a dense cutter head comprises the following steps: The sintered block was cut into cutter head units with a length of 40 mm, a width of 10 mm, and a thickness of 3 mm using wire cutting technology; The blade is surface-finished by a belt grinder, and the final surface roughness is controlled between 0.6-0.8 μm; The allowable deviation of the external dimensions of the tool head after processing is ±0.05mm.

[0030] In summary, this application includes at least one of the following beneficial technical effects: 1. This invention utilizes a multi-metal system and high-performance functional ceramic composites, specifically combining metals such as cobalt, iron, copper, and silver with ceramic powders such as Ti3SiC2, B4C, and ZnAl-LDH, to create a new diamond saw blade composite. Through rational component design and mutual collaboration, the material not only improves hardness but also enhances wear resistance. Compared with traditional single-metal-based materials, the diamond saw blade of this invention exhibits a significant wear reduction effect during the cutting process, capable of handling longer periods of high-intensity work, and solving the problems of rapid wear and short service life of traditional materials during long-term cutting.

[0031] 2. This invention utilizes a plasma-assisted hot-pressing sintering process. This innovative process allows for more uniform and dense sintering of the metal matrix, significantly improving the strength and toughness of the blade. Conventional sintering processes typically struggle to achieve uniform temperature distribution, and are prone to cracking and structural unevenness. Plasma-assisted hot-pressing, on the other hand, quickly and effectively binds powder particles tightly together, improving the blade's overall performance and making it more stable in high-temperature cutting environments. This avoids the structural instability and performance degradation associated with conventional techniques due to low density.

[0032] 3. This invention addresses the problem of uneven powder dispersion during the production process through unique functional coating ball milling technology. This innovation creates a tighter bond between the metal and ceramic powders, resulting in a more uniform particle size distribution and enhanced overall material performance. Compared to traditional direct mixing processes, the coating ball milling process effectively avoids material stratification and unevenness, resulting in higher consistency and greater stability in practical applications of diamond saw blades, thereby extending their service life and improving operating efficiency.

[0033] 4. This invention significantly improves the thermal stability and crack resistance of saw blades by carefully controlling the ratio of each component and sintering conditions. Compared to traditional metal blades, diamond saw blades using this invention are more capable of maintaining their morphology and performance stability in the face of high temperature fluctuations and shocks. In particular, in thermal shock tests, the examples exhibited virtually no cracking, whereas traditional technologies are prone to crack propagation under thermal stress, affecting cutting accuracy and lifespan. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a flow chart of the preparation method of this application. DETAILED DESCRIPTION

[0035] The following is combined with Figure 1 , further details of this application are given.

[0036] Please see the attached Figure 1 : Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0037] Example 1: Raw material components (by mass fraction): Cobalt powder: 42.5 parts, iron powder: 45.5 parts, copper powder: 7 parts, silver powder: 4 parts, ZnAl-LDH: 2.5 parts, Ti3SiC2 powder: 1.5 parts, B4C nanopowder: 1.0 parts, niobium powder: 1.0 parts, molding aid: 1.5 parts.

[0038] Preparation steps: Ball milling: Ti3SiC2, B4C and niobium powders were mixed with copper powder and then wet-milled. Zirconia ceramic balls were used as the milling medium. Anhydrous ethanol was used as the dispersant. The ball-to-material ratio was 12:1. The speed was 300 rpm and the milling time was 2 hours. After ball milling, vacuum drying was performed (70°C for 1.5 hours).

[0039] Mixing and granulation: The composite coated powder is evenly mixed with cobalt powder, iron powder, silver powder, and B4C nanopowder, 1.5 parts of polyvinyl alcohol is added as a molding aid, and granulation is performed using a spray drying method with a nozzle diameter of 0.75 mm and a spray temperature of 170°C to obtain spherical particles with a particle size of 80-150 μm.

[0040] Cold pressing: Use a mold for cold pressing with a pressing pressure of 80 MPa and a time of 45 seconds to form a green blank.

[0041] Plasma-assisted hot pressing sintering: The green blank is placed in a vacuum chamber with a pulse current frequency of 8 Hz and a current density of 10 A / cm 2 First, heat the temperature to 450℃ and keep it for 10 minutes, then heat it to 690℃, apply 15MPa pressure and keep it for 15 minutes, then cool it to obtain a dense metal blade.

[0042] Segment cutting and processing: The segment is processed into a segment with a size of 40×10×3mm by wire cutting technology, and the surface is trimmed by a belt grinder with a roughness controlled at Ra0.7μm.

[0043] Example 2: Raw material components (by mass fraction): Cobalt powder: 40 parts, iron powder: 43 parts, copper powder: 6 parts, silver powder: 3 parts, ZnAl-LDH: 2 parts, Ti3SiC2 powder: 1 part, B4C nanopowder: 0.8 parts, niobium powder: 0.8 parts, molding aid: 1 part.

[0044] Preparation steps: Ball milling: wet ball milling, ball-to-material ratio of 10:1, rotation speed of 250 rpm, time, 1.5 hours, using anhydrous ethanol and zirconia balls as ball milling media; after ball milling, vacuum dry at 60°C for 1 hour.

[0045] Mixing and granulation: Add 1 part of ethyl cellulose as an auxiliary agent, and use a mechanical compression granulation method to press the mixture into irregular particles with a particle size of about 80 μm.

[0046] Cold pressing: Apply a pressure of 80 MPa and press for 30 seconds to obtain a green blank.

[0047] Sintering: plasma-assisted hot pressing under vacuum conditions, pulse frequency 5 Hz, current density 8 A / cm 2 ; First heat to 450℃ and keep warm for 10 minutes, then heat to 680℃, apply 15MPa pressure and keep warm for 15 minutes.

[0048] Segment processing: After wire cutting, the shape is 40×10×3mm, the surface roughness is controlled at Ra0.8μm, and the processing size deviation is controlled at ±0.05mm.

[0049] Example 3: Raw material components (by mass fraction): Cobalt powder: 45 parts, iron powder: 48 parts, copper powder: 8 parts, silver powder: 5 parts, ZnAl-LDH: 3 parts, Ti3SiC2: powder 2 parts, B4C nanopowder: 1.2 parts, niobium powder: 1.2 parts, molding aid: 2 parts.

[0050] Preparation steps: Ball milling: wet ball milling, ball-to-material ratio 15:1, rotation speed 350 rpm, time 2.5 hours, ball milling medium is zirconia balls, anhydrous ethanol is used as solvent; vacuum drying at 80 ° C for 2 hours.

[0051] Mixing and granulation: Add 2 parts of zinc stearate as an auxiliary agent, use spray drying method to granulate, the nozzle diameter is 1.0 mm, the drying temperature is 180°C, and spherical particles with a particle size of 150 μm are obtained.

[0052] Cold press molding: pressure 80MPa, pressing for 60 seconds.

[0053] Sintering: pulse frequency 10Hz, current density 12A / cm 2 , first heat to 450℃ and keep warm for 10 minutes, then heat to 700℃ and keep warm at 15MPa pressure for 15 minutes.

[0054] Segment processing: The size of the wire cutting segment is 40×10×3mm, the surface roughness is controlled at Ra0.6μm, and the precision processing controls the size deviation to ±0.05mm.

[0055] Comparative Example 1: Compared with Example 1, the difference is that the ZnAl-LDH component is not added, and the rest are the same.

[0056] Comparative Example 2: Compared with Example 1, the difference is that the Ti3SiC2 powder is reduced to 0.5 parts by mass, and the rest are the same.

[0057] Comparative Example 3: Compared with Example 1, the difference is that the niobium powder (Nb) component is not added, and the rest are the same.

[0058] Comparative Example 4: Compared with Example 1, the difference is that copper powder is not used for functional ceramic coating, and the rest are the same.

[0059] Comparative Example 5: Compared with Example 1, the difference is that plasma-assisted hot pressing sintering is not used, and the rest are the same.

[0060] Comparative Example 6: Compared with Example 1, the difference is that the addition amount of ZnAl-LDH is increased to 4 parts by mass, and the rest are the same.

[0061] Experiment 1: Experimental purpose: To evaluate the wear resistance of different experimental groups (Example 1, Comparative Example 1, Comparative Example 2) during high-strength stone cutting, and to determine the wear rate of each sample per unit time.

[0062] Experimental steps: Sample preparation: Each comparison group of samples (Example 1, Comparative Example 1, Comparative Example 2) ensures that the diameter, thickness and diamond coating of each group of samples are consistent.

[0063] Equipment Commissioning and Setup: Set the abrasion tester to stone cutting mode and select a standard wear test stone (e.g., granite). Set the cutting speed to 30 m / min, the cutting depth to 1 mm, and the load pressure to 10 MPa. Ensure that the ambient temperature and humidity are within laboratory standards (20 ± 2°C, 50% ± 5% humidity).

[0064] Cutting Test: Each sample is placed on the abrasion tester and the machine is started to cut. The total cutting time for each sample is 30 minutes. During the cutting process, the cutting progress is regularly recorded and the tester load is adjusted to ensure a stable load for each test.

[0065] Data Collection and Recording: After cutting, each sample was weighed and the difference in mass before and after cutting was recorded. The wear resistance was determined by measuring the change in mass. The experiment was repeated three times for each sample to ensure data reliability.

[0066] Data Recording and Analysis: After each experiment, record the cutting time, mass change, and other parameters that may affect wear (such as load pressure) for each group of samples. After the experiment is completed, calculate the average wear volume for each group (experimental results are shown in Table 1).

[0067] Table 1: Cutting wear resistance comparison test data In the comparative experiment of cutting wear resistance, Example 1 demonstrated its superior wear resistance in the process of cutting high-hardness stone, reflecting the significant advantages of the composite material and multi-phase reinforcement design proposed in the present invention. Through the synergistic effect of the carefully designed multi-metal system and the reinforcing phase, the saw blade of Example 1 showed a lower wear rate during the cutting process. This result is closely related to the reasonable combination of components such as cobalt powder, iron powder and copper powder in the material. The high hardness and good thermal conductivity of cobalt and iron effectively slow down the heat accumulation during the cutting process, thereby reducing the wear on the blade surface. The addition of copper powder not only increases the toughness of the material, but also plays a good role in resisting thermal expansion, thereby enhancing the stability of the material in a high-temperature environment and reducing deformation and wear during cutting. These characteristics show that the design of Example 1 fully utilizes the advantages of metal-based composite materials and improves the wear resistance of traditional metal saw blades.

[0068] The introduction of ZnAl-LDH plays a key role as a grain boundary strengthener, especially in improving the thermal stability and wear resistance of the material. The layered structure of ZnAl-LDH can form a stable interface phase during the sintering process, reducing the thermal expansion and crack generation of the material at high temperatures, thereby improving the comprehensive performance of the metal cutter head at high temperatures. This is verified in Example 1. Compared with the sample lacking ZnAl-LDH in Comparative Example 1, Example 1 shows a significant wear resistance advantage. The strengthening effect of ZnAl-LDH enhances the structural stability of the material during the cutting process and reduces the thermal stress generated during high-temperature cutting. This makes Example 1 more durable and stable during long-term cutting, reduces thermal damage caused by high temperature, and further improves cutting efficiency.

[0069] The significant improvement in the cutting wear resistance of the present invention comes not only from the optimization of the material ratio, but also from the sophisticated sintering and preparation process. Through the plasma-assisted hot pressing sintering process, Example 1 effectively optimizes the microstructure of the material while maintaining high density, thereby improving the wear resistance of the blade. Compared with conventional sintering processes, the plasma-assisted sintering process can provide a more uniform heat distribution, so that the various components in the material can be better combined under high temperature conditions to form a highly dense composite structure. This process improves the wear resistance and crack resistance of the blade, enabling it to better withstand the various stresses and temperature fluctuations generated during the cutting process in actual applications, further enhancing its performance in extreme working environments.

[0070] Experiment 2: Experimental purpose: To evaluate the performance of different experimental groups (Example 1, Comparative Example 4, Comparative Example 5) in terms of the density and dimensional accuracy of the cutter head after sintering, and to verify the influence of different preparation processes on the metal cutter head by comparing the density and dimensional error of each sample.

[0071] Experimental steps: Sample preparation: For each comparative group of samples (Example 1, Comparative Example 4, Comparative Example 5), ensure that the diameter, thickness, and diamond coating of all samples remain consistent.

[0072] Equipment debugging and setting: Debug digital precision measuring instruments to ensure that the measuring instrument accuracy is better than ±0.01mm, adjust the laser density meter to ensure its accuracy within the experimental range. Set the compressor simulation sintering conditions to ensure the stability of the pressure during the pressing process.

[0073] Segment Dimension Measurement: Use digital precision measuring instruments to measure the diameter and thickness of each sample, repeating the measurement three times for each sample and calculating the dimensional error (i.e., deviation from the standard size). Analyze the dimensional stability of each sample to assess its accuracy.

[0074] Sintering experiment: The samples in the control group were placed in a high-temperature sintering furnace, the sintering temperature was set to 700°C, and maintained for 15 minutes. The samples in comparative example 5 were sintered conventionally, while the samples in Example 1 and comparative example 4 were sintered using plasma-assisted hot pressing. Each sample maintained a pressure of 15 MPa and cooled to room temperature after sintering.

[0075] Cutting head density test: Use a laser densitometer to measure the density of each cutting head. Repeat the test three times according to the experimental requirements, calculate the average density, and compare it with the standard value.

[0076] Data recording and analysis: The dimensional error and density of the cutter head will be used as the main data of this experiment. The dimensional deviation and density values ​​of each group of samples will be recorded and statistically analyzed (the experimental results are shown in Table 2).

[0077] Table 2: Comparative test results of tool head density and dimensional accuracy In the comparative experiment of the density and dimensional accuracy of the cutter head, Example 1 demonstrated its excellent densification effect during the sintering process, which is mainly due to the plasma-assisted hot pressing sintering process proposed in the present invention. This process uses rapid heating by pulsed current to enable the cutter head to reach a uniform high-temperature state in a short time, greatly promoting the bonding force between metal powders, thereby improving the density. In comparison with conventional sintering processes, Example 1 has a higher density, indicating the unique advantages of plasma-assisted sintering in improving material bonding strength and internal structure uniformity. This dense metal matrix plays a vital role in improving the strength, toughness and wear resistance of the blade, and also avoids the problem of blade breakage or damage during cutting due to insufficient density.

[0078] The dimensional accuracy of Example 1 is also better than that of the control group, especially after high-temperature sintering, Example 1 maintains dimensional consistency and stability through a precise sintering process. This performance advantage is closely related to the functional coated ball milling process adopted in the present invention. During the ball milling process, the particle size distribution and fluidity of the material before sintering are ensured by uniform dispersion and reasonable coating of each component, and cracks or dimensional instability during the sintering process are avoided. In particular, after the addition of strengthening phases such as Ti3SiC2 and ZnAl-LDH, they form a stable network structure in the material, which effectively limits the unevenness of thermal expansion, thereby reducing dimensional errors. This shows that Example 1, which combines functional coated ball milling with plasma sintering technology, has higher dimensional stability and consistency, and meets the needs of high-precision cutting applications.

[0079] In the comparative experiment, the density and dimensional accuracy of Comparative Example 4, which did not adopt the functional coating ball milling step, and Comparative Example 5, which did not use plasma-assisted sintering, were lower than those of Example 1. The lack of a coated ball milling process makes it difficult to maintain uniform dispersion of powder particles during the sintering process, resulting in insufficient density of the sintered blade, which is prone to microcracks or deformation. The conventional hot pressing sintering process cannot quickly form a high-density structure in a short time like plasma-assisted hot pressing, resulting in an increase in the dimensional error of the sample in Comparative Example 5. Therefore, the process innovation of sintering and powder preparation in Example 1 effectively improves the overall performance of the material, demonstrating the obvious advantages of the present invention in improving the precision and durability of cutting tools.

[0080] Experiment 3: Experimental purpose: To evaluate the structural stability and cracking risk of different experimental groups (Example 1, Comparative Example 3, Comparative Example 6) under repeated thermal shock environment.

[0081] Experimental steps: Sample preparation: For each comparative group of samples (Example 1, Comparative Example 3, Comparative Example 6), ensure that all samples are consistent in size, thickness, etc.

[0082] Equipment commissioning and setup: Adjust the high-temperature furnace to 1000°C and set the heating rate to 5°C / min to ensure a stable temperature rise for the sample. Configure the vibration and shock testing machine, set the vibration and shock cycle to 30 seconds, and immediately cool the sample to room temperature after each shock.

[0083] Thermal shock test: Each sample was first heated in a high-temperature furnace to 1000°C and held for 10 minutes. A vibration shock tester then applied thermal shock. The sample underwent three cycles of rapid heating (1000°C, 10 minutes) and cooling (room temperature, rapid cooling). The cracking condition of the sample was recorded after each shock.

[0084] Crack Detection and Hardness Measurement: After each thermal shock, the surface of each sample was visually inspected for cracks, and the number and size of cracks were recorded. Subsequently, the surface hardness of the sample was measured using a digital hardness tester, and the hardness value was recorded.

[0085] Data Recording and Analysis: The number of cracks, crack area, and hardness of each sample were recorded and statistically analyzed. The impact of thermal shock on the different samples was analyzed to assess the crack resistance and thermal stability of each group of samples (Table 3).

[0086] Table 3: Thermal stability and structural integrity comparison test data In the comparative experiment of thermal stability and structural integrity, Example 1 demonstrated its excellent crack resistance and stability under high temperature thermal shock environment, which is due to the multiphase strengthening design adopted in the present invention. In Example 1, the addition of strengthening phases such as Ti3SiC2, B4C and ZnAl-LDH formed a dense network structure under high temperature conditions. This structure effectively inhibited the thermal expansion and thermal stress generation of the material and slowed down the propagation of cracks. These strengthening phases not only improved the hardness of the material, but also significantly enhanced its crack resistance under extreme temperature fluctuations, indicating that Example 1 has significant advantages in thermal stability. In contrast, the comparison groups lacking these strengthening phases (such as Comparative Example 3 and Comparative Example 6) showed more cracks and decreased hardness, further demonstrating the key role of multiphase material systems in improving high temperature crack resistance.

[0087] In addition, the plasma-assisted hot pressing sintering process used in Example 1 is also one of the important factors in improving thermal stability. This process uses pulsed current to uniformly heat the sample in a short period of time, thereby achieving rapid and uniform material sintering and avoiding thermal stress concentration caused by uneven temperature distribution. Through this process, the material of Example 1 can maintain a high level of structural integrity in a high-temperature environment, reducing cracks and damage caused by temperature differences. Compared with traditional sintering methods, the plasma-assisted hot pressing sintering process can more effectively enhance the material's resistance to thermal shock, allowing the blade of Example 1 to maintain good thermal stability after repeated thermal shocks.

[0088] Compared with Example 1, Comparative Example 5 which did not adopt plasma-assisted sintering and Comparative Example 3 which lacked niobium powder were lacking in thermal stability, which was manifested by the generation of cracks and a significant decrease in hardness. Niobium powder, as one of the reinforcing phases, plays an important role in improving the high-temperature resistance of the material. It can form a stable metal-ceramic composite phase during the sintering process, further improving the crack resistance of the material. However, the control group that lacked niobium powder or used a conventional sintering process failed to achieve the same efficient reinforcement effect as Example 1, resulting in more cracks in the thermal shock test, which illustrates the key role of precise composition control and sintering process for thermal stability. The design of Example 1 fully utilizes the synergistic effect of the various components in the material, improving the stability and durability of the material in extreme working environments.

[0089] The examples of this specific embodiment are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, any equivalent changes made based on the structure, shape, and principle of this application should be included in the scope of protection of this application.

Claims

1. A composite diamond saw blade with high thermal stability, comprising a metal blade head and a steel base, characterized in that: The metal cutter head is composed of the following raw material components in parts by mass: Cobalt powder: 40-45 parts; Iron powder: 43-48 parts; Copper powder: 6-8 parts; Silver powder: 3-5 parts; ZnAl-LDH: 2-3 parts; Ti3SiC2 powder: 1-2 parts; B4C nano powder: 0.8-1.2 parts; Niobium powder: 0.8-1.2 parts; Molding aid: 1-2 parts.

2. The composite diamond saw blade with high thermal stability according to claim 1, characterized in that: The ZnAl-LDH is zinc aluminum double hydroxide, the intercalation anion of the zinc aluminum double hydroxide is selected from carbonate, nitrate or chloride, the molar ratio of Zn to Al of the zinc aluminum double hydroxide is 2:1, and the particle size distribution is 100-300 nm.

3. The composite diamond saw blade with high thermal stability according to claim 1, characterized in that: The Ti3SiC2 is a ceramic conductive phase with a hexagonal crystal structure, a particle size of 200-500nm, and a purity greater than 98%.

4. The composite diamond saw blade with high thermal stability according to claim 1, characterized in that: The B4C nanopowder is β-crystal boron carbide with a particle size of 50-100 nm and an equiaxed distribution. The molding aid is selected from ethyl cellulose, polyvinyl alcohol or zinc stearate.

5. A method for preparing a composite diamond saw blade with high thermal stability, for preparing a composite diamond saw blade with high thermal stability according to claims 1-4, characterized in that: The following steps are involved: S1. Weigh the raw materials of the metal cutting head in a preset ratio, including cobalt powder, iron powder, copper powder, silver powder, ZnAl-LDH, Ti3SiC2 powder, B4C nanopowder, niobium powder and forming additives; S2, mixing Ti3SiC2, B4C and niobium powder with copper powder and ball milling to form a functional coated composite powder; S3, mixing the functional coated composite powder with cobalt powder, iron powder, silver powder and B4C nanopowder, adding a molding aid, and then forming the metal powder and functional component premix into spherical or irregular particles with a particle size of 80-150 μm; S4, cold pressing the spherical or irregular particles under a pressure of 80 MPa to obtain a green blank; S5. The blank is sintered by plasma-assisted hot pressing under vacuum conditions. First, it is heated to 450°C and kept warm for 10 minutes. Then, the temperature is raised to 680-700°C. A pressure of 15 MPa is applied and kept warm for 15 minutes. Then, the blank is cooled to obtain a dense tool head.

6. The method for preparing a composite diamond saw blade with high thermal stability according to claim 5, characterized in that: The mixing of Ti3SiC2, B4C and niobium powder with copper powder and ball milling comprises the following steps: Pretreatment is performed by wet ball milling, wherein the ball milling medium is zirconia ceramic balls and anhydrous ethanol is used as the solvent; The ball milling time is set to 1.5-2.5 hours, the ball milling speed is controlled at 250-350 rpm, and the ball-to-material ratio is controlled at 10:1-15:1 to obtain a composite coated powder; The composite coated powder after ball milling is vacuum dried at a temperature of 60-80° C. for 1-2 hours.

7. The method for preparing a composite diamond saw blade with high thermal stability according to claim 5, characterized in that: The method of preparing the metal powder and the functional component premix into spherical or irregular particles with a particle size of 80-150 μm comprises the following steps: The spherical or irregular particles with a particle size of 80-150 μm are prepared by spray drying granulation technology or mechanical compression granulation method; Before the granulation, 1-2 parts by mass of a molding aid is added, the spray drying temperature is set to 160-180°C, and the nozzle diameter is 0.5-1.0mm; The particles are sintered by plasma hot pressing to form a dense cutting head, which is finally fixed to the steel substrate by high-frequency induction welding. The welding temperature is controlled at 700-750°C and the welding time is 10-12 seconds.

8. The method for preparing a composite diamond saw blade with high thermal stability according to claim 5, characterized in that: Described obtaining green blank comprises the following steps: The ball-milled composite coated powder is mixed evenly with cobalt powder, iron powder, silver powder and B4C nanopowder, and then pressed into shape using a dry cold pressing process under a pressure of 80 MPa. The molding time is controlled within 30-60 seconds. The mixed powder is pre-vibrated and sieved before pressing to control the particle size between 80-150 μm to obtain a uniformly filled green blank structure; Through plasma-assisted hot pressing sintering, ZnAl-LDH is heated to 450℃ and decomposed into ZnO and Al2O3, which are distributed at the metal matrix grain boundaries.

9. The method for preparing a composite diamond saw blade with high thermal stability according to claim 5, characterized in that: The plasma-assisted hot pressing sintering comprises the following steps: Densification is achieved by plasma-assisted hot pressing sintering, with a pulse current frequency of 5-10 Hz and a current density of 8-12 A / cm 2 ; The plasma field generates directional ion migration inside the material, causing the binder metal phase to diffuse and bond; Apply an axial pressure of 15 MPa and keep the temperature at 680-700°C for 15 minutes to form a dense metal matrix.

10. The method for preparing a composite diamond saw blade with high thermal stability according to claim 5, characterized in that: The preparation of the dense cutter head comprises the following steps: The sintered block was cut into cutter head units with a length of 40 mm, a width of 10 mm, and a thickness of 3 mm using wire cutting technology; The blade is surface-finished by a belt grinder, and the final surface roughness is controlled between 0.6-0.8 μm; The allowable deviation of the external dimensions of the tool head after processing is ±0.05mm.

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