A laser welded diamond saw with ultra-narrow kerf and a preparation method thereof

Abstract

The present application relates to the technical field of diamond saw blade, in particular to a laser welded diamond saw blade for ultra-narrow slit cutting and a preparation method thereof.The laser welded diamond saw blade comprises the following raw materials: copper-cobalt-tin alloy powder, tungsten carbide powder, titanium aluminum nitride, spherical cobalt powder, rare earth yttrium powder, phosphorus iron powder and diamond abrasive particles.The core of the preparation method is the combination of powder metallurgy pre-preparation of the cutter head and precise laser welding process, especially the innovative laser welding process.The prepared diamond saw blade has high weld strength, narrow heat affected zone and minimal substrate deformation, solves the problems of substrate deformation, insufficient weld strength and short service life of traditional saw blades in ultra-narrow slit cutting, and is perfectly suitable for ultra-narrow slit cutting scenarios with extremely high requirements for precision and stability.

Description

Technical Field

[0001] This invention relates to the field of diamond saw blade technology, and more specifically, to a laser-welded diamond saw blade for ultra-narrow slit cutting and its preparation method. Background Technology

[0002] A diamond saw blade is a cutting tool widely used in the processing of hard and brittle materials such as concrete, refractory materials, stone, and ceramics. A diamond saw blade mainly consists of a substrate and a cutting head. The substrate is the main supporting part that holds the cutting head together. The cutting head is the part that performs the cutting action during use.

[0003] In precision machining fields such as ultra-narrow slit cutting, including semiconductor dicing, ceramic substrate splitting, and fine processing of precious stone, extreme demands are placed on the cutting accuracy, stability, and lifespan of saw blades. Existing diamond saw blades mostly employ high-frequency brazing or sintering processes to bond the cutting head to the substrate; however, these methods face significant bottlenecks when achieving ultra-narrow slit cutting.

[0004] On the one hand, in order to achieve a narrow kerf, the thickness of the saw blade base and the cutting head needs to be reduced to the extreme. However, the traditional welding method has a large heat input and a wide action area, which can easily cause thermal deformation and residual stress in the thin steel base, thereby causing swaying and shaking during the cutting process, which seriously restricts the straightness and vertical accuracy of the kerf.

[0005] On the other hand, the strength of traditional solder layers is limited. When subjected to high-frequency, high-load precision cutting, the solder layer is prone to fatigue microcracks, which increases the risk of early blade detachment. This not only shortens the saw blade life but may also cause safety hazards such as flying fragments during high-speed cutting. Summary of the Invention

[0006] The purpose of this invention is to solve the problem that, in the prior art, when diamond saw blades are used for ultra-narrow slit cutting, thermal deformation, residual stress, and solder layer strength affect the cutting quality and saw blade life.

[0007] The purpose of this invention is to provide a laser-welded diamond saw blade for ultra-narrow slit cutting and its preparation method. The material system is formed by combining copper-cobalt-tin alloy powder, titanium-aluminum nitride and other components with diamond abrasive grains, and is precisely combined with laser technology to fundamentally solve the problems of matrix deformation, insufficient weld strength and short life of traditional saw blades in ultra-narrow slit cutting.

[0008] To achieve the above objectives, one objective of this invention is to provide a laser-welded diamond saw blade for ultra-narrow slit cutting, comprising the following raw materials in the following mass percentages:

[0009] The composition consists of 30-45% copper-cobalt-tin alloy powder, 10-18% tungsten carbide powder, 3-8% titanium aluminum nitride (TiAlN), 8-15% spherical cobalt powder, 0.5-2.5% rare earth yttrium powder, 1-3% phosphorus iron powder, and the balance being diamond abrasive grains.

[0010] As a further improvement to this technical solution, the spherical cobalt powder has a particle size of 52-70 micrometers, and the mass percentage of cobalt in the copper-cobalt-tin alloy powder is 5-8%, and the mass percentage of tin is 8-12%.

[0011] In summary, in this invention, the copper-cobalt-tin alloy powder serves as the main binder phase, where cobalt significantly enhances the high-temperature strength and oxidation resistance of the binder phase, tin strengthens the binder phase through solid solution reinforcement, and the copper matrix ensures the fluidity of the molten metal during laser welding. The titanium-aluminum nitride and tungsten carbide powder synergistically construct a dispersed, reinforced, and wear-resistant skeleton. The ultra-hard properties of titanium-aluminum nitride suppress the high-temperature softening of the cutting tool, and tungsten carbide adjusts the composite thermal expansion coefficient to achieve matching with the steel matrix.

[0012] The spherical cobalt powder enhances the toughness of the binder phase through a solid solution strengthening mechanism; the rare earth yttrium powder is used to refine the grain structure of the weld zone; the phosphorus iron powder creates a process window for low heat input laser welding through the dual effects of lowering the melting point and deep deoxidation.

[0013] The diamond abrasive grains serve as the primary cutting medium, and the copper-cobalt-tin alloy powder forms a strong metallurgical bond with the steel substrate during laser welding. Its excellent oxidation resistance ensures the stability of the sintering and welding processes. The titanium-aluminum nitride maintains structural stability during the laser welding thermal cycle, effectively suppressing grain coarsening in the heat-affected zone.

[0014] The second objective of this invention is to provide a method for preparing the aforementioned laser-welded diamond saw blade for ultra-narrow slit cutting, comprising the following steps:

[0015] Step S1: Weigh the raw materials according to the mass ratio;

[0016] First, copper-cobalt-tin alloy powder, tungsten carbide powder, titanium aluminum nitride powder, spherical cobalt powder, rare earth yttrium powder, iron phosphorus powder and diamond abrasive grains are mixed to obtain a cutting head composite powder. Then, the cutting head composite powder is made into a cutting head blank.

[0017] Step S2: The green cutter head is sintered to obtain a pre-made cutter head block, and then alloy steel is used as the base of the saw blade to pre-treat the area to be welded.

[0018] Step S3: The sintered cutter head preform is precisely placed on the welding area of ​​the pretreated saw blade substrate and fixed with a clamp to obtain the workpiece;

[0019] The workpiece is placed in a sealed welding chamber, argon gas is introduced as a protective gas, and welding is performed using a fiber laser or a disk laser.

[0020] During welding, the laser power is 800-1500W, the spot diameter is 0.2-0.5mm, and the welding speed is 5-20mm / s;

[0021] Step S4: After welding, the saw blade is obtained. Then, the saw blade is placed in a tempering furnace and kept warm for 2-4 hours.

[0022] Finally, the saw blade is subjected to dynamic balancing correction, end face runout fine grinding, and surface coating treatment to obtain a diamond saw blade.

[0023] As a further improvement to this technical solution, in step S1, copper-cobalt-tin alloy powder, tungsten carbide powder, titanium-aluminum nitride powder, spherical cobalt powder, rare earth yttrium powder and iron phosphorus powder are first placed in a three-dimensional mixer and mixed for 4-8 hours under inert gas protection.

[0024] Subsequently, the mixed metal powder is mixed with diamond abrasive grains for 1-2 hours to obtain the tool head composite powder.

[0025] As a further improvement to this technical solution, in step S1, the blade composite powder is loaded into a mold of a specific shape and cold-pressed under a pressure of 300-600MPa to produce a blade blank with a predetermined geometric shape and size.

[0026] As a further improvement to this technical solution, in step S2, the green blank of the cutter head is sent into a vacuum sintering furnace for sintering;

[0027] During sintering, the temperature is increased to 800-850℃ at a rate of 5-10℃ / min and held for 30min.

[0028] The temperature is then increased to a sintering temperature of 880-920℃ at a rate of 3-5℃ / min, and held for 45-90min to obtain the cutter head preform.

[0029] As a further improvement to this technical solution, in step S2, alloy steel is selected as the saw blade substrate, the area to be welded is flattened and cleaned, and then the area to be welded is activated by sandblasting or laser cleaning to remove the oxide layer and increase the surface roughness.

[0030] As a further improvement to this technical solution, in step S3, when the clamp is fixed, the assembly gap between the cutter head preform block and the saw blade base is <0.05mm.

[0031] As a further improvement to this technical solution, in step S3, welding is performed using an oscillating welding method.

[0032] As a further improvement to this technical solution, in step S4, the tempering furnace temperature is 280-350℃.

[0033] The core of the preparation method provided by this invention lies in the combination of powder metallurgy prefabrication of the cutter head and precise laser welding process. In particular, the innovative laser welding process results in diamond saw blades with high weld strength, narrow heat-affected zone, and minimal matrix deformation, making them perfectly suited for ultra-narrow slit cutting scenarios with extremely high requirements for precision and stability.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] In this laser-welded diamond saw blade for ultra-narrow slit cutting and its preparation method, a high-performance bonding system is constructed using copper-cobalt-tin alloy powder. Cobalt is used to improve high-temperature strength and oxidation resistance, while tin is used to strengthen the bonding phase. At the same time, the dispersed strengthening skeleton composed of titanium aluminum nitride and tungsten carbide ensures the dimensional stability of the cutter head. Combined with the grain boundary purification of rare earth yttrium powder, the solid solution strengthening of spherical cobalt powder, and the melting point reduction and deoxidation effect of iron phosphorus powder, ideal conditions are created for subsequent laser welding.

[0036] Furthermore, an oscillating laser welding process is adopted to promote atomic interdiffusion in the copper-cobalt-iron multi-element system under argon protection, forming a gradient connection structure with fine eutectic structure as the main component and intermetallic compounds. After low-temperature tempering to eliminate residual stress, the weld strength and toughness are synergistically improved while ensuring the flatness of the matrix. This solves the problems of matrix deformation, insufficient weld strength and short life of traditional saw blades in ultra-narrow slit cutting. Attached Figure Description

[0037] Figure 1 This is a flowchart of the present invention;

[0038] Figure 2 A schematic diagram showing the change in end face runout of a diamond saw blade when the mass percentage of titanium aluminum nitride is different.

[0039] Figure 3 This diagram illustrates the wear rate of diamond saw blades with different mass percentages of titanium aluminum nitride. Detailed Implementation

[0040] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] One of the objectives of this invention is to provide a laser-welded diamond saw blade for ultra-narrow slit cutting, comprising the following raw materials in the following mass percentages: 30-45% copper-cobalt-tin alloy powder, 10-18% tungsten carbide powder, 3-8% titanium aluminum nitride (TiAlN), 8-15% spherical cobalt powder, 0.5-2.5% rare earth yttrium powder, 1-3% phosphorus iron powder, with the balance being diamond abrasive grains.

[0042] The spherical cobalt powder has a particle size of 52-70 micrometers, and the mass percentage of cobalt in the copper-cobalt-tin alloy powder is 5-8%, while the mass percentage of tin is 8-12%.

[0043] In the above material formulation, copper-cobalt-tin alloy powder is the main binder phase, which serves as the main brazing filler metal during laser welding. Copper provides good wettability and fluidity, cobalt significantly improves the high-temperature strength and oxidation resistance of the binder phase, and tin enhances the strength of the binder phase through solid solution strengthening. This alloy system exhibits good stability during sintering and welding.

[0044] Titanium aluminum nitride powder, as an ultra-hard ceramic phase, is dispersed in the binder phase, greatly improving the hardness, wear resistance, and high-temperature stability of the cutting tool. It maintains structural stability under the rapid thermal cycling of laser welding, effectively inhibiting softening in the heat-affected zone.

[0045] Tungsten carbide powder and titanium aluminum nitride (TiAlN) form a composite wear-resistant skeleton, which further improves the wear resistance of the cutting tip, while adjusting the thermal expansion coefficient of the cutting tip to better match it with the steel matrix.

[0046] Spherical cobalt powder is used to improve powder flowability and make the compact density more uniform. During sintering and welding, cobalt can dissolve in the copper-based binder phase, playing a solid solution strengthening role and promoting the retention of diamond.

[0047] Rare earth yttrium powder acts as a highly efficient grain boundary cleaner, adsorbing and removing oxides from the powder surface and improving the wettability between powder particles. Simultaneously, rare earth elements refine the grains within the weld and the cutting tool, significantly enhancing their strength and toughness. Furthermore, using iron phosphorus powder as a flux reducer lowers the melting temperature of the binder phase, thus enabling laser welding with lower heat input. Additionally, phosphorus possesses strong deoxidizing capabilities, further purifying the weld metal.

[0048] Please see Figure 1 As shown, a second objective of this invention is to provide a method for preparing the aforementioned laser-welded diamond saw blade for ultra-narrow slit cutting, comprising the following steps:

[0049] Step S1: Weigh the raw materials according to the mass ratio.

[0050] First, copper-cobalt-tin alloy powder, tungsten carbide powder, titanium aluminum nitride powder, spherical cobalt powder, rare earth yttrium powder and phosphorus iron powder are placed in a three-dimensional mixer and mixed for 4-8 hours under inert gas protection to ensure uniform distribution of each component.

[0051] Subsequently, the mixed metal powder and diamond abrasive grains are mixed a second time using a drum mixer for 1-2 hours to avoid diamond particle breakage and density segregation, thereby obtaining a uniformly composed blade composite powder.

[0052] The uniformly mixed cutter head composite powder is then loaded into a mold of a specific shape and cold-pressed under a pressure of 300-600MPa to produce a cutter head blank with a predetermined geometry and size.

[0053] Step S2: The green cutter blank is sintered to obtain a preformed cutter blank. Specifically, the green cutter blank is sent into a vacuum sintering furnace for sintering.

[0054] During sintering, the temperature is increased to 800-850℃ at a rate of 5-10℃ / min and held for 30 minutes to fully remove the binder;

[0055] The temperature is then increased to 880-920℃ at a rate of 3-5℃ / min and held for 45-90 minutes. During this process, the copper-cobalt-tin binder phase melts and impregnates and coats the diamond and hard particles, forming a dense metallurgical bond, ultimately yielding a high-strength diamond tool tip preform.

[0056] High-strength alloy steel is then selected as the saw blade base. The area to be welded is flattened and cleaned. Then, the area to be welded is activated by sandblasting or laser cleaning to remove the oxide layer and increase the surface roughness, thereby improving the welding bond strength.

[0057] Step S3: Precisely place the sintered cutter head preform onto the welding area of ​​the pretreated alloy steel saw blade substrate, and fix it using a special high-temperature resistant fixture to obtain the workpiece to be processed. It is worth noting that when fixing with the fixture, the assembly gap between the cutter head preform and the saw blade substrate should be <0.05mm.

[0058] The assembled workpiece is placed in a sealed welding chamber, and high-purity argon gas is introduced as a protective gas. Welding is performed using a fiber laser or disk laser. During welding, the laser power is 800-1500W, the spot diameter is 0.2-0.5 mm, and the welding speed is 5-20 mm / s. An oscillating welding method is used to widen the weld and promote full element diffusion, while reducing defects such as porosity and cracks. The laser beam precisely irradiates the interface between the cutting head and the substrate. The high-energy-density laser instantly melts the binder phase metal at the bottom of the cutting head, which then diffuses and fuses with the molten steel substrate surface, forming a narrow, deep, and dense metallurgical bond weld in an extremely short time (milliseconds).

[0059] Step S4: After welding, the saw blade is obtained. Then, the saw blade is placed in a low-temperature tempering furnace at a temperature of 280-350℃ for 2-4 hours to eliminate residual welding stress and prevent deformation during subsequent cutting.

[0060] Finally, the saw blade undergoes dynamic balancing correction, end face runout fine grinding, and surface coating (such as anti-rust coating) treatment to obtain a high-performance laser-welded diamond saw blade for ultra-narrow slit cutting.

[0061] The following specific embodiments will further illustrate the laser-welded diamond saw blade for ultra-narrow slot cutting and its preparation method provided by the present invention.

[0062] Example 1

[0063] Step S1: Weigh out 30% copper-cobalt-tin alloy powder, 10% tungsten carbide powder, 8% titanium aluminum nitride (TiAlN), 8% spherical cobalt powder, 2.5% rare earth yttrium powder, and 1% phosphorus iron powder according to the mass ratio, with the remainder being diamond abrasive grains.

[0064] The spherical cobalt powder has a particle size of 70 micrometers, and the mass percentage of cobalt in the copper-cobalt-tin alloy powder is 5%, while the mass percentage of tin is 12%.

[0065] First, copper-cobalt-tin alloy powder, tungsten carbide powder, titanium aluminum nitride powder, spherical cobalt powder, rare earth yttrium powder and phosphorus iron powder are placed in a three-dimensional mixer and mixed for 8 hours under inert gas protection.

[0066] Subsequently, the mixed metal powder and diamond abrasive grains were mixed a second time using a drum mixer for a short time of 1 hour to obtain a uniformly composed blade composite powder.

[0067] The uniformly mixed cutter head composite powder is then loaded into a mold of a specific shape and cold-pressed under a pressure of 600 MPa to produce a cutter head blank with a predetermined geometry and size.

[0068] Step S2: The green cutter blank is sintered to obtain a preformed cutter blank. Specifically, the green cutter blank is sent into a vacuum sintering furnace for sintering.

[0069] During sintering, the temperature is increased to 850℃ at a rate of 5℃ / min and held for 30min;

[0070] The temperature was then increased to 920℃ at a rate of 3℃ / min and held for 45 minutes to obtain the cutter head preform.

[0071] Alloy steel is then selected as the saw blade base. The area to be welded is flattened and cleaned, and then laser cleaning is used to activate the area to be welded, remove the oxide layer and increase the surface roughness.

[0072] Step S3: Precisely place the sintered cutter head preform onto the welding area of ​​the pretreated alloy steel saw blade substrate, and fix it using a clamp to obtain the workpiece. It is worth noting that when fixing with the clamp, the assembly gap between the cutter head preform and the saw blade substrate should be <0.05mm.

[0073] The workpiece was placed in a sealed welding chamber, and argon gas was introduced as a protective gas. Welding was performed using a fiber laser with a laser power of 1500W, a spot diameter of 0.2 mm, and a welding speed of 20 mm / s. An oscillating welding method was used for the welding process.

[0074] Step S4: After welding, the saw blade is obtained. Then, the saw blade is placed in a tempering furnace at a temperature of 280℃ and kept warm for 4 hours.

[0075] Finally, the saw blade is subjected to dynamic balancing correction, end face runout fine grinding, and surface coating treatment to obtain a diamond saw blade.

[0076] Example 2

[0077] Step S1: Weigh out 40% copper-cobalt-tin alloy powder, 15% tungsten carbide powder, 5% titanium aluminum nitride (TiAlN), 12% spherical cobalt powder, 1.5% rare earth yttrium powder, and 2% phosphorus iron powder according to the mass ratio, with the remainder being diamond abrasive grains.

[0078] The spherical cobalt powder has a particle size of 60 micrometers, and the mass percentage of cobalt in the copper-cobalt-tin alloy powder is 6.5%, while the mass percentage of tin is 10%.

[0079] First, copper-cobalt-tin alloy powder, tungsten carbide powder, titanium aluminum nitride powder, spherical cobalt powder, rare earth yttrium powder and phosphorus iron powder are placed in a three-dimensional mixer and mixed for 6 hours under inert gas protection.

[0080] Subsequently, the mixed metal powder and diamond abrasive grains were mixed a second time using a drum mixer for a short time of 1 hour to obtain a uniformly composed blade composite powder.

[0081] The uniformly mixed cutter head composite powder is then loaded into a mold of a specific shape and cold-pressed under a pressure of 500 MPa to produce a cutter head blank with a predetermined geometry and size.

[0082] Step S2: The green cutter blank is sintered to obtain a preformed cutter blank. Specifically, the green cutter blank is sent into a vacuum sintering furnace for sintering.

[0083] During sintering, the temperature is increased to 820℃ at a rate of 8℃ / min and held for 30min;

[0084] The temperature was then increased to 900℃ at a rate of 4℃ / min and held for 65 minutes to obtain the cutter head preform.

[0085] Alloy steel is then selected as the saw blade base. The area to be welded is flattened and cleaned, and then laser cleaning is used to activate the area to be welded, remove the oxide layer and increase the surface roughness.

[0086] Step S3: Precisely place the sintered cutter head preform onto the welding area of ​​the pretreated alloy steel saw blade substrate, and fix it using a clamp to obtain the workpiece. It is worth noting that when fixing with the clamp, the assembly gap between the cutter head preform and the saw blade substrate should be <0.05mm.

[0087] The workpiece was placed in a sealed welding chamber, and argon gas was introduced as a protective gas. Welding was performed using a fiber laser with a laser power of 1100W, a spot diameter of 0.4 mm, and a welding speed of 15 mm / s. An oscillating welding method was used for the welding process.

[0088] Step S4: After welding, the saw blade is obtained. Then, the saw blade is placed in a tempering furnace at a temperature of 310℃ and kept warm for 3 hours.

[0089] Finally, the saw blade is subjected to dynamic balancing correction, end face runout fine grinding, and surface coating treatment to obtain a diamond saw blade.

[0090] Example 3

[0091] Step S1: Weigh out 45% copper-cobalt-tin alloy powder, 18% tungsten carbide powder, 3% titanium aluminum nitride (TiAlN), 15% spherical cobalt powder, 0.5% rare earth yttrium powder, and 3% phosphorus iron powder according to the mass ratio, with the remainder being diamond abrasive grains.

[0092] The spherical cobalt powder has a particle size of 52 micrometers, and the mass percentage of cobalt in the copper-cobalt-tin alloy powder is 8%, and the mass percentage of tin is 8%.

[0093] First, copper-cobalt-tin alloy powder, tungsten carbide powder, titanium aluminum nitride powder, spherical cobalt powder, rare earth yttrium powder and phosphorus iron powder are placed in a three-dimensional mixer and mixed for 4 hours under inert gas protection.

[0094] Subsequently, the mixed metal powder and diamond abrasive grains were mixed a second time using a drum mixer for a short time of 2 hours to obtain a uniformly composed blade composite powder.

[0095] The uniformly mixed cutter head composite powder is then loaded into a mold of a specific shape and cold-pressed under a pressure of 300 MPa to produce a cutter head blank with a predetermined geometry and size.

[0096] Step S2: The green cutter blank is sintered to obtain a preformed cutter blank. Specifically, the green cutter blank is sent into a vacuum sintering furnace for sintering.

[0097] During sintering, the temperature is increased to 800℃ at a rate of 10℃ / min and held for 30min;

[0098] The temperature was then increased to 880℃ at a rate of 5℃ / min and held for 90 minutes to obtain the cutter head preform.

[0099] Alloy steel is then selected as the saw blade base. The area to be welded is flattened and cleaned, and then activated by sandblasting to remove the oxide layer and increase the surface roughness.

[0100] Step S3: Precisely place the sintered cutter head preform onto the welding area of ​​the pretreated alloy steel saw blade substrate, and fix it using a clamp to obtain the workpiece. It is worth noting that when fixing with the clamp, the assembly gap between the cutter head preform and the saw blade substrate should be <0.05mm.

[0101] The workpiece is placed in a sealed welding chamber, and argon gas is introduced as a protective gas. A disk laser is used for welding. During welding, the laser power is 800W, the spot diameter is 0.5 mm, and the welding speed is 5 mm / s. Welding is performed using an oscillating welding method.

[0102] Step S4: After welding, the saw blade is obtained. Then, the saw blade is placed in a tempering furnace at a temperature of 350℃ and kept warm for 2 hours.

[0103] Finally, the saw blade is subjected to dynamic balancing correction, end face runout fine grinding, and surface coating treatment to obtain a diamond saw blade.

[0104] Saw blades were prepared according to Examples 1-3, and then the diamond saw blades were subjected to the following performance tests:

[0105] End face runout test: Install the saw blade on the precision positioning plate that simulates the working spindle, rotate the saw blade, and measure the axial runout of the base end face (the runout for ultra-narrow slit cutting is usually less than 0.02mm).

[0106] Cut quality test: High-hardness and high-wear-resistance materials are selected as test pieces, such as zirconia ceramics, granite, or silica bricks. The test saw blade is installed on a standard precision cutting machine for cutting. The cut surface is observed for chipping or corner breakage, and the roughness of the cut surface is measured using a surface roughness meter.

[0107] Cutting life test: Under standard conditions, a specific specimen is cut continuously or intermittently until the saw blade wears down to the point that it can no longer cut effectively or the kerf width exceeds the tolerance range. During this period, the machine is stopped periodically to measure the radial wear of the cutter head and calculate the wear rate per unit cutting length.

[0108] The values ​​obtained from the above performance tests are recorded in Table 1.

[0109] Table 1 Performance values ​​of saw blades prepared in Examples 1-3

[0110] Example 1 Example 2 Example 3 End face runout / mm 0.016 0.015 0.015 Surface roughness of cut / μm 3.2 2.9 3.0 <![CDATA[Wear rate / (mm / m 2 )]]> 0.0030 0.0029 0.0029

[0111] Table 1 shows that the end face runout of the saw blades prepared in Examples 1-3 is less than 0.02 mm, the surface roughness of the cut is not higher than 3.2 μm, and the wear rate is less than 0.0030 mm / m. 2 This invention provides a laser-welded diamond saw blade for ultra-narrow slit cutting and its preparation method, which can produce diamond saw blades with good ultra-narrow slit cutting performance and lifespan.

[0112] In this invention, a high-performance bonding system is first constructed using copper-cobalt-tin alloy powder. Cobalt significantly improves the high-temperature strength and oxidation resistance of the bonding phase, while tin enhances the strength of the bonding phase through solid solution strengthening. Simultaneously, titanium aluminum nitride and tungsten carbide synergistically construct a dispersion-strengthened framework. The former, with its ultra-hard properties and high-temperature stability, suppresses the plastic deformation of the cutting head during high-speed cutting, while the latter achieves matching with the steel substrate by adjusting the composite thermal expansion coefficient, jointly ensuring the dimensional stability of ultra-narrow slit cutting. Furthermore, rare earth yttrium powder preferentially purifies grain boundaries due to its strong oxygen affinity, while spherical cobalt powder enhances the toughness of the bonding phase through a solid solution strengthening mechanism. Phosphorus iron powder creates ideal conditions for subsequent low-heat-input laser welding through the dual effects of lowering the melting point and deep deoxidation.

[0113] Furthermore, a precisely controlled laser welding process is employed. Under argon protection, a high-energy-density laser beam causes the active binder phase at the bottom of the saw blade to eutectic with the steel substrate surface. An oscillating welding mode promotes atomic interdiffusion in the copper-cobalt-iron multi-element system, completing the transformation from dendrite to fine eutectic structure within milliseconds. During this process, cobalt continuously migrates towards the steel substrate to form an Fe-Ti intermetallic compound reinforcement layer, while the grain boundary segregation effect of rare-earth yttrium effectively inhibits the initiation of weld cracks. Ultimately, a composite connection structure with metallurgical bonding and a gradient transition in microstructure is constructed at the interface. Combined with a subsequent low-temperature tempering process to eliminate residual stress, the saw blade maintains the flatness of the substrate while achieving a synergistic improvement in weld strength and toughness, fundamentally solving the problems of substrate deformation and early failure in ultra-narrow slit cutting scenarios.

[0114] Test case

[0115] In this invention, the mass percentage of titanium aluminum nitride (TiAlN) in the diamond saw blade tip is 3-8%. If its content deviates from this optimized range, it will cause a series of structural and performance problems. Too low a TiAlN content will prevent the formation of a continuous, dispersed reinforcing skeleton, resulting in insufficient volume fraction of the composite wear-resistant phase, and a significant decrease in the high-temperature hardness and resistance to plastic deformation of the blade tip. During high-speed cutting, the binder phase is prone to softening and flowing under frictional heat, accelerating the shedding of diamond particles, causing the blade tip to exhibit abnormal wear morphology, and the kerf width to gradually increase with the cutting process, making it impossible to maintain the dimensional accuracy required for ultra-narrow kerf cutting.

[0116] Excessive titanium aluminum nitride content can lead to agglomeration of hard phase particles, disrupting the continuity of the binder phase. This microstructural inhomogeneity significantly increases the brittleness of the cutting tool, making it prone to microcracks under cutting impact loads. Simultaneously, excessive titanium aluminum nitride excessively increases the cutting tool's coefficient of thermal expansion, exacerbating its mismatch with the steel matrix and increasing residual stress at the laser welding interface. This internal stress, under cutting vibration, easily leads to stress corrosion cracking at the weld edge, significantly reducing the high-cycle fatigue life of the weld joint.

[0117] To verify that the 3-8% mass proportion of titanium aluminum nitride in the diamond saw blade is one of the key factors enabling the preparation of a laser-welded diamond saw blade for ultra-narrow slit cutting and its preparation method provided in this invention, which can produce diamond saw blades with good ultra-narrow slit cutting performance and lifespan, this experimental example, based on Example 1 above, only changes the mass proportion of titanium aluminum nitride, setting it to 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10% in the diamond saw blade. Saw blades are then prepared, and the end face runout and wear rate of the saw blades are tested according to the test methods given in the above examples. The results are as follows: Figure 2 , Figure 3 As shown.

[0118] according to Figure 2 It can be seen that when the mass percentage of titanium aluminum nitride in the diamond saw blade is 1%, 2%, 9% or 10%, that is, not 3-8%, the end face runout of the prepared saw blade is significantly higher than that of the prepared saw blade when the mass percentage of titanium aluminum nitride in the diamond saw blade is 3%, 4%, 5%, 6%, 7% or 8%.

[0119] according to Figure 3 It can be seen that when the mass percentage of titanium aluminum nitride in the diamond saw blade is 1%, 2%, 9% or 10%, that is, not 3-8%, the wear rate of the saw blade is significantly higher than that of the saw blade prepared when the mass percentage of titanium aluminum nitride in the diamond saw blade is 3%, 4%, 5%, 6%, 7% or 8%.

[0120] In summary, the 3-8% mass ratio of titanium aluminum nitride in the diamond saw blade is one of the important factors that enable the laser-welded diamond saw blade for ultra-narrow slit cutting and its preparation method provided by this invention to produce a diamond saw blade with good ultra-narrow slit cutting performance and lifespan.

[0121] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a laser-welded diamond saw blade for ultra-narrow slit cutting, characterized in that, Includes the following steps: Step S1: Weigh out 30-45% copper-cobalt-tin alloy powder, 10-18% tungsten carbide powder, 3-8% titanium aluminum nitride, 8-15% spherical cobalt powder, 0.5-2.5% rare earth yttrium powder, 1-3% phosphorus iron powder, and the remainder is diamond abrasive grains according to the mass ratio. First, copper-cobalt-tin alloy powder, tungsten carbide powder, titanium aluminum nitride powder, spherical cobalt powder, rare earth yttrium powder, iron phosphorus powder and diamond abrasive grains are mixed to obtain a cutting head composite powder. Then, the cutting head composite powder is made into a cutting head blank. Step S2: The green cutter head is sintered to obtain a pre-made cutter head block, and then alloy steel is used as the base of the saw blade to pre-treat the area to be welded. Step S3: The sintered cutter head preform is precisely placed on the welding area of ​​the pretreated saw blade substrate and fixed with a clamp to obtain the workpiece; The workpiece is placed in a sealed welding chamber, argon gas is introduced as a protective gas, and welding is performed using a fiber laser or a disk laser. During welding, the laser power is 800-1500W, the spot diameter is 0.2-0.5mm, and the welding speed is 5-20mm / s; Step S4: After welding, the saw blade is obtained. Then, the saw blade is placed in a tempering furnace and kept warm for 2-4 hours. Finally, the saw blade is subjected to dynamic balancing correction, end face runout fine grinding, and surface coating treatment to obtain a diamond saw blade.

2. The method for preparing a laser-welded diamond saw blade for ultra-narrow slit cutting according to claim 1, characterized in that: In step S1, the spherical cobalt powder has a particle size of 52-70 micrometers, and the mass percentage of cobalt in the copper-cobalt-tin alloy powder is 5-8%, and the mass percentage of tin is 8-12%.

3. The method for preparing a laser-welded diamond saw blade for ultra-narrow slit cutting according to claim 1, characterized in that: In step S1, copper-cobalt-tin alloy powder, tungsten carbide powder, titanium aluminum nitride powder, spherical cobalt powder, rare earth yttrium powder and phosphorus iron powder are first placed in a three-dimensional mixer and mixed for 4-8 hours under inert gas protection. Subsequently, the mixed metal powder is mixed with diamond abrasive grains for 1-2 hours to obtain the tool head composite powder.

4. The method for preparing a laser-welded diamond saw blade for ultra-narrow slit cutting according to claim 1, characterized in that: In step S1, the composite powder of the cutting head is loaded into a mold of a specific shape and cold-pressed under a pressure of 300-600MPa to produce a cutting head blank with a predetermined geometric shape and size.

5. The method for preparing a laser-welded diamond saw blade for ultra-narrow slit cutting according to claim 1, characterized in that: In step S2, the green cutter head is fed into a vacuum sintering furnace for sintering. During sintering, the temperature is increased to 800-850℃ at a rate of 5-10℃ / min and held for 30min. The temperature is then increased to a sintering temperature of 880-920℃ at a rate of 3-5℃ / min, and held for 45-90min to obtain the cutter head preform.

6. The method for preparing a laser-welded diamond saw blade for ultra-narrow slit cutting according to claim 1, characterized in that: In step S2, alloy steel is selected as the saw blade base. The area to be welded is flattened and cleaned. Then, the area to be welded is activated by sandblasting or laser cleaning to remove the oxide layer and increase the surface roughness.

7. The method for preparing a laser-welded diamond saw blade for ultra-narrow slit cutting according to claim 1, characterized in that: In step S3, when the clamp is fixed, the assembly gap between the cutter head preform block and the saw blade base is <0.05mm.

8. The method for preparing a laser-welded diamond saw blade for ultra-narrow slit cutting according to claim 1, characterized in that: In step S3, welding is performed using an oscillating welding method.

9. The method for preparing a laser-welded diamond saw blade for ultra-narrow slit cutting according to claim 1, characterized in that: In step S4, the tempering furnace temperature is 280-350℃.

10. A laser-welded diamond saw blade for ultra-narrow slit cutting, prepared by the method according to any one of claims 1-9, characterized in that, Including the following raw materials: The mixture comprises copper-cobalt-tin alloy powder, tungsten carbide powder, titanium aluminum nitride, spherical cobalt powder, rare earth yttrium powder, iron phosphorus powder, and diamond abrasive grains. The copper-cobalt-tin alloy powder serves as the main binder phase, with cobalt enhancing the high-temperature strength and oxidation resistance of the binder phase, and tin strengthening the binder phase through solid solution reinforcement. The copper matrix ensures the fluidity of the molten metal during laser welding. The titanium aluminum nitride and tungsten carbide powder synergistically construct a dispersed, reinforced, and wear-resistant skeleton. The ultra-hard properties of the titanium aluminum nitride suppress high-temperature softening of the cutting tool, while the tungsten carbide adjusts the composite thermal expansion coefficient to achieve compatibility with the steel matrix. The spherical cobalt powder enhances the toughness of the binder phase through a solid solution strengthening mechanism; the rare earth yttrium powder is used to refine the grain structure of the weld zone; the phosphorus iron powder creates a process window for low heat input laser welding through the dual effects of lowering the melting point and deep deoxidation. The diamond abrasive grains serve as the primary cutting medium, and the copper-cobalt-tin alloy powder forms a strong metallurgical bond with the steel substrate during laser welding, ensuring the stability of the welding process. The titanium-aluminum nitride maintains structural stability during the laser welding thermal cycle, effectively suppressing grain coarsening in the heat-affected zone.

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