A circular saw blade with a sawtooth surface containing a composite micro-texture and a lubricating coating and a method of making the same

Abstract

The application discloses a circular saw blade with a sawtooth surface containing a composite micro-texture and a lubricating coating and a preparation method thereof, and belongs to the technical field of mechanical cutting machining and manufacturing. The preparation method comprises the following steps: immersing the circular saw blade in a solvent, uniformly processing shallow pit micro-texture with a depth of 1-5 microns on the sawtooth surface of the circular saw blade by adopting nanosecond laser, processing deep groove grid-shaped micro-texture with a depth of 8-20 microns on the surface of the shallow pit micro-texture in air after drying by adopting nanosecond laser, obtaining the composite micro-texture sawtooth, and depositing a lubricating coating on the surface of the composite micro-texture sawtooth by electric jet flow, and performing high-temperature solidification after drying, thereby obtaining the circular saw blade. The composite micro-texture surface is constructed on the sawtooth surface, the problem of insufficient cutting performance of a single micro-texture surface is avoided, the problem of insufficient bonding strength between the lubricating coating and the sawtooth substrate is avoided, the service life of the lubricating coating is long, and the abrasion of the sawtooth material is reduced.

Description

Technical Field

[0001] This invention relates to the field of mechanical cutting and manufacturing technology, and in particular to a circular saw blade with a composite microtexture and a lubricating coating on the tooth surface, and a method for preparing the same. Background Technology

[0002] The information disclosed in the background section of this invention is intended only to enhance the understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Friction between the saw teeth and the workpiece material is one of the main causes of circular saw blade failure. When circular saw blades cut metal materials, the cutting temperature on the saw teeth can reach 400–1000℃, and the pressure in the blade-chip contact zone can reach 2–3 GPa. Furthermore, the high-speed flow of chips generates intense friction on the saw teeth, leading to severe wear on the cutting surface and the formation of a "built-up edge" at the blade tip, significantly affecting the surface finish and reducing the lifespan of the circular saw blade. The friction contact zone between the saw teeth and chips can be divided into an adhesion zone and a sliding zone. Friction is more intense in the adhesion zone, where the tangential friction force per unit area exceeds the shear yield limit of the material, resulting in severe wear on the saw tooth surface. As the chips reach the friction sliding zone, the friction gradually decreases, causing less wear on the saw tooth surface. While cutting fluid can reduce the cutting temperature, it is difficult for the fluid to penetrate the blade-chip friction contact zone, leaving a harsh frictional environment in the adhesion zone of the saw tooth surface. Lubricating coatings have a layered molecular structure and exhibit an extremely low coefficient of friction during the friction process, making them an effective alternative to cutting fluid. Applying a lubricating coating to the saw tooth surface can effectively reduce the coefficient of friction and alleviate wear on the saw tooth surface. However, the bonding strength between the lubricating coating and the saw tooth is poor, and the lubricating coating gradually wears away as sawing continues.

[0004] Microtexturing technology has become a highly effective and widely used surface modification method due to its simple preparation and significant effects. Patent CN110524013A discloses a microtextured cutting tool with a nano-coating, which improves the cutting performance and durability of the tool by preparing a microtexture on the tool surface. However, simply preparing a nano-coating on the microtexture surface has limited impact on improving the tool's cutting performance. Patent CN103060528A discloses a laser composite strengthening process, which first prepares a microtexture on the tool surface, then performs laser shock peening on the microtexture surface before preparing a coating to improve the tool's service life. Although laser shock peening can change the surface hardness and morphology of the tool, it also severely affects the performance of the microtexture. Furthermore, laser shock peening cannot reach the interior of the microtexture, making it difficult to achieve the combined goal of improving tool performance through laser shock peening and microtexturing. Patent CN112746248A discloses a self-lubricating coated cutting tool, which uses a composite coating of TiVZnC and MoTeHfN layers on the tool surface to reduce friction. However, the bonding strength between the composite coating and the substrate is insufficient, which seriously affects the service life of the lubricating coating.

[0005] Therefore, how to provide a micro-textured toothed circular saw blade that combines good cutting performance with a long service life of lubricating coating is an urgent problem to be solved. Summary of the Invention

[0006] In view of this, the present invention provides a circular saw blade with a composite microtexture and a lubricating coating on the saw tooth surface and a method for preparing the same. The present invention constructs a composite microtexture surface on the saw tooth surface, which avoids the problem of insufficient cutting performance of a single microtexture surface, and at the same time avoids the problem of insufficient bonding strength between the lubricating coating and the saw tooth substrate.

[0007] In a first aspect, the present invention provides a method for preparing a circular saw blade with a composite microtexture and a lubricating coating on the tooth surface, comprising the following steps:

[0008] A circular saw blade is immersed in a solvent, and a nanosecond laser is used to uniformly process shallow pit microtextures with a depth of 1-5 μm on the surface of the saw teeth. After drying, a deep groove grid-like microtexture with a depth of 8-20 μm is processed on the surface of the shallow pit microtextures in air using a nanosecond laser, thus obtaining composite microtextured saw teeth. A lubricating coating is deposited on the surface of the composite microtextured saw teeth by electro-jet deposition, and after drying, it is cured at high temperature to obtain the final product.

[0009] Preferably, the solvent is selected from water or ethanol; the solvent thickness on the surface of the circular saw blade teeth is 1-3 mm.

[0010] Preferably, the groove width of the deep groove mesh microtexture is 20-40 μm, and the groove spacing of the deep groove mesh microtexture is 100-300 μm.

[0011] Preferably, in the step of uniformly processing shallow pits with a depth of 1-5 μm on the surface of the circular saw blade teeth using a nanosecond laser, the overlap rate of the nanosecond laser processing is 40-60%, the nanosecond laser processing speed is 5-20 mm / s, the nanosecond laser frequency is 150-250 kHz, the nanosecond laser power is 10-30 W, and the number of processing times is 3-6.

[0012] Preferably, in the step of processing the shallow pit microtexture surface with a depth of 8-20 μm using a nanosecond laser in air after drying, the nanosecond laser processing frequency is 10-50 kHz, the scanning speed is 100-200 mm / s, the nanosecond laser power is 4-10 W, and the processing times are 1-2 times.

[0013] Preferably, the step of electro-jet deposition of a lubricating coating on the surface of the composite microtextured saw teeth specifically involves: mixing lubricating material powder with a binder to prepare a lubricating coating solution, and depositing the lubricating coating on the surface of the composite microtextured saw teeth by electro-jet deposition.

[0014] Furthermore, the lubricating material powder is selected from one or more of MoS2, WS2, or polytetrafluoroethylene; the binder is selected from one or more of polyamide-imide (PAI) or polyphenylene sulfide (PPS); and the solvent of the lubricating coating solution is ethanol.

[0015] Furthermore, the mass ratio of the lubricating material powder, binder, and solvent is (5-10):(2-5):(20-50); the particle size of the lubricating material powder is 10-100 nm.

[0016] Preferably, the nozzle moving speed of the electrojet deposition is 6-10 mm / s, the deposition distance is 3-6 mm, the voltage is 2.4-4.0 kV, the number of deposition layers is 8-20, and the thickness of the lubricating coating is 10-20 μm.

[0017] Preferably, in the high-temperature curing step after drying, the drying temperature is 60-90°C and the drying time is 20-60 min; the high-temperature curing temperature is 180-260°C and the high-temperature curing time is 10-30 min.

[0018] Secondly, the present invention provides a circular saw blade with a composite microtexture and a lubricating coating on the saw tooth surface prepared by the above preparation method.

[0019] Compared with the prior art, the present invention has achieved the following beneficial effects:

[0020] This invention creates a composite microtexture on the surface of a circular saw blade tooth using a two-step nanosecond laser process. This avoids the shortcomings of a single microtexture surface, improving not only the hardness and wear resistance of the saw tooth material surface but also increasing the contact area with the lubricating coating and providing good storage space for the lubricating coating, thus extending its service life. Under friction test conditions of 20N load and 10mm / s sliding speed, the lubricating coating can be used for more than 1500s. Simultaneously, it reduces the friction coefficient of the saw tooth surface to below 0.15, alleviating wear on the saw tooth material. Moreover, the preparation method of this invention is simple and has excellent application prospects. Attached Figure Description

[0021] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation thereof. Obviously, those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0022] Figure 1 This is a schematic diagram illustrating the preparation process of the circular saw blades with composite microtexture and lubricating coating on the saw tooth surface in Examples 1-3 of the present invention;

[0023] Figure 2 These are atomic force microscopy images of the surface of the initial circular saw blade teeth of the present invention and the surfaces of the circular saw blade teeth of Comparative Examples 1 to 3, wherein (a) is the surface of the initial circular saw blade teeth, (b) is the surface of the circular saw blade teeth of Comparative Example 1, (c) is the surface of the circular saw blade teeth of Comparative Example 2, and (d) is the surface of the circular saw blade teeth of Comparative Example 3.

[0024] In the figure, 1. Circular saw blade teeth; 2. Deionized water; 3. Shallow pit microtexture; 4. Nanosecond laser; 5. Deep groove mesh microtexture; 6. Lubricating coating; 7. Electrojets deposition equipment. Detailed Implementation

[0025] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0026] This invention provides a method for preparing a circular saw blade with a composite microtexture and a lubricating coating on the tooth surface, comprising the following steps:

[0027] A circular saw blade is immersed in a solvent, and a nanosecond laser is used to uniformly process shallow pit microtextures with a depth of 1-5 μm on the surface of the saw teeth. After drying, a deep groove grid-like microtexture with a depth of 8-20 μm is processed on the surface of the shallow pit microtextures in air using a nanosecond laser, thus obtaining composite microtextured saw teeth. A lubricating coating is deposited on the surface of the composite microtextured saw teeth by electro-jet deposition, and after drying, it is cured at high temperature to obtain the final product.

[0028] This invention constructs a composite microtexture on the saw tooth surface through a two-step nanosecond laser processing method. This composite microtexture not only improves the wear resistance and fatigue resistance of the saw tooth material, but also increases the contact area with the lubricating coating, providing good storage space for the lubricating coating and thus increasing its service life. Even after the lubricating coating wears off, the composite microtexture surface can maintain a low coefficient of friction. The deposition of the lubricating coating can significantly reduce the coefficient of friction on the saw tooth surface, which is beneficial for reducing wear and increasing the service life of the circular saw blade.

[0029] The circular saw blade teeth of the present invention are preferably made of cemented carbide.

[0030] In this invention, the solvent is selected from water or ethanol, more preferably water; the solvent thickness on the surface of the circular saw blade teeth is 1-3 mm. The first nanosecond laser processing is carried out in the solvent, which absorbs and diffuses the heat generated by the laser processing in a timely manner, avoiding the accumulation of molten material on the processing surface, and the constructed shallow pit microtexture is evenly distributed on the saw tooth surface.

[0031] The present invention does not impose special restrictions on the drying steps after processing the shallow pit microtexture. Natural air drying or oven drying can be used, as long as no solvent residue is left on the surface of the saw teeth.

[0032] In this invention, the groove width of the deep groove mesh microtexture is 20-40 μm, and the groove spacing of the deep groove mesh microtexture is 100-300 μm, more preferably 100-200 μm.

[0033] In this invention, in the step of uniformly processing shallow pits with a depth of 1-5 μm on the surface of the circular saw blade teeth using a nanosecond laser, the overlap rate of the nanosecond laser processing is 40-60%, more preferably 45-55%; the nanosecond laser processing speed is 5-20 mm / s, more preferably 8-12 mm / s; the nanosecond laser frequency is 150-250 kHz, more preferably 180-220 kHz; the nanosecond laser power is 10-30 W, more preferably 15-20 W; and the number of processing times is 3-6.

[0034] In this invention, in the step of processing the shallow pit microtexture surface with a depth of 8-20 μm using a nanosecond laser in air after drying, the nanosecond laser processing frequency is 10-50 kHz, more preferably 20-40 kHz; the scanning speed is 100-200 mm / s; the nanosecond laser power is 4-10 W, more preferably 6-10 W; and the number of processing times is 1-2.

[0035] In this invention, the step of electro-jet deposition of a lubricating coating on the surface of the composite microtextured saw teeth specifically involves: mixing lubricating material powder with a binder to prepare a lubricating coating solution, and depositing the lubricating coating on the surface of the composite microtextured saw teeth by electro-jet deposition.

[0036] In this invention, the lubricating material powder is selected from one or more of MoS2, WS2, or polytetrafluoroethylene; the binder is selected from one or more of polyamide-imide (PAI) or polyphenylene sulfide (PPS); and the solvent of the lubricating coating solution is ethanol.

[0037] In this invention, the mass ratio of the lubricating material powder, binder, and solvent is (5-10):(2-5):(20-50); the particle size of the lubricating material powder is 10-100 nm.

[0038] In this invention, the nozzle moving speed of the electrojet deposition is 6-10 mm / s, the deposition distance is 3-6 mm, the voltage is 2.4-4.0 kV, more preferably 3.0-3.5 kV; the number of deposition layers is 8-20, more preferably 8-15; and the thickness of the lubricating coating is 10-20 μm.

[0039] In this invention, during the high-temperature curing step after drying, the drying temperature is 60–90°C, and the drying time is 20–60 minutes, allowing the organic solvents in the coating to evaporate. The high-temperature curing temperature is 180–260°C, and the high-temperature curing time is 10–30 minutes, allowing the coating to form.

[0040] The present invention also provides a circular saw blade with a composite microtexture and a lubricating coating on the saw tooth surface prepared by the above preparation method.

[0041] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0042] Example 1

[0043] This embodiment provides a method for preparing a circular saw blade with a composite microtexture and a lubricating coating on the saw tooth surface. A schematic diagram of the preparation process is shown below. Figure 1 As shown. In this embodiment, the circular saw blade teeth 1 are made of YG8 cemented carbide.

[0044] (1) Immerse the circular saw blade in deionized water 2 medium. The thickness of deionized water 2 on the surface of the circular saw blade teeth 1 is 2mm. Use nanosecond laser 4 to perform laser shock strengthening on the surface of the circular saw blade teeth 1. The overlap rate of laser processing is 50%, the laser processing speed is 10mm / s, the frequency is 200kHz, the power is 20W, and the number of processing times is 4. Irregular shallow pit microtextures 3 with a depth of 1~5μm are processed on the surface of the saw teeth. After processing, dry treatment is performed.

[0045] (2) A nanosecond laser 4 was used in air to process a deep groove mesh microtexture 5 on the surface of the circular saw blade teeth 1. The laser processing frequency was 20kHz, the scanning speed was 150mm / s, the power was 8W, and the processing was done once. The depth of the prepared deep groove mesh microtexture 5 was 10μm, the groove width was 30μm, and the spacing between parallel grooves was 150μm. A composite microtexture was prepared on the surface of all the circular saw blade teeth 1.

[0046] (3) Mix 4 parts of MoS2 powder with a particle diameter of 20 nm, 3 parts of polytetrafluoroethylene, 3 parts of polyamide-imide (PAI) binder and 30 parts of anhydrous ethanol to prepare a lubricating coating solution (all parts are by mass). Deposit the lubricating coating 6 on the surface of the composite microtextured sawtooth using an electro-jet deposition device 7. The nozzle moving speed is 6 mm / s, the deposition distance is 4 mm, the voltage is 3.2 kV, the number of deposition layers is 10, and the thickness of the lubricating coating 6 is 15 μm.

[0047] (4) After the lubricating coating 6 is deposited, it is baked and dried on an 80°C baking platform for 30 minutes, and then placed in a 200°C heating oven for high-temperature curing for 20 minutes, and then cooled to room temperature with the oven.

[0048] Example 2

[0049] The difference between this embodiment and embodiment 1 is that step (1) is different. Step (1) of this embodiment is as follows:

[0050] The circular saw blade was immersed in deionized water 2 medium, and the thickness of the deionized water 2 on the surface of the circular saw blade teeth 1 was 3mm. A nanosecond laser 4 was used to perform laser shock strengthening on the surface of the circular saw blade teeth 1. The overlap rate of the laser processing was 40%, the laser processing speed was 15mm / s, the frequency was 150kHz, the power was 15W, and the number of processing times was 3. Irregular shallow pit microtextures 3 with a depth of 1-5μm were processed on the surface of the circular saw blade teeth 1. After processing, the blade was dried.

[0051] Example 3

[0052] The difference between this embodiment and embodiment 1 is that step (2) is different. Step (2) of this embodiment is as follows:

[0053] In air, a nanosecond laser 4 was used to process a deep groove mesh-like microtexture 5 on the surface of the circular saw blade teeth 1. The laser processing frequency was 40kHz, the scanning speed was 160mm / s, the power was 10W, and the processing was performed once. The prepared deep groove mesh-like microtexture 5 had a depth of 10μm, a groove width of 30μm, and a spacing of 150μm between parallel grooves. A composite microtexture was prepared on the surface of all the circular saw blade teeth 1.

[0054] Comparative Example 1

[0055] The difference between this comparative example and Example 1 is that this comparative example does not include steps (2) to (4), but only processes irregular shallow pit microtexture 3 with a depth of 1 to 5 μm on the surface of the circular saw blade teeth 1.

[0056] Comparative Example 2

[0057] The difference between this comparative example and Example 1 is that this comparative example does not include steps (1), (2), and (4), but only processes a deep groove mesh-like microtexture 5 on the surface of the circular saw blade teeth 1. The specific steps are as follows:

[0058] A nanosecond laser 4 was used to process a deep groove mesh-like microtexture 5 on the surface of the circular saw blade teeth 1 in air. The laser processing frequency was 20kHz, the scanning speed was 150mm / s, the power was 8W, and the processing was performed once. The prepared deep groove mesh-like microtexture 5 had a depth of 10μm, a groove width of 30μm, and a spacing of 150μm between parallel grooves.

[0059] Comparative Example 3

[0060] The difference between this comparative example and Example 1 is that this comparative example does not perform steps (3) and (4), that is, it does not deposit the lubricating coating 6.

[0061] Comparative Example 4

[0062] The difference between this comparative example and Example 1 is that this comparative example does not perform steps (1) and (2), but directly deposits a lubricating coating 6 on the surface of the circular saw blade teeth 1 by electro-jet deposition, and finally obtains a circular saw blade with an electro-jet deposited lubricating coating on the surface of the saw teeth.

[0063] Test case

[0064] Atomic force microscopy was used to measure the surface of the initial circular saw blade teeth and the circular saw blade teeth of Comparative Examples 1–3. Figure 2 As shown.

[0065] The hardness of the saw teeth surface of the initial circular saw blade and the circular saw teeth surfaces of Comparative Examples 1 to 3 were measured, as shown in Table 1.

[0066] Table 1. Hardness data of the initial circular saw blade tooth surface and the circular saw blade tooth surfaces of Comparative Examples 1-3.

[0067] Hardness (HV) 1344 1520 1425 1579

[0068] As can be seen from Table 1, constructing microtextures on the surface of circular saw blade teeth can improve the hardness of the saw tooth material, and the composite microtexture surface in Comparative Example 3 showed the highest increase in hardness.

[0069] The friction coefficients of the initial circular saw blade tooth surfaces, the surfaces of Examples 1-3, and Comparative Examples 1-4 were measured, and the results are shown in Table 2.

[0070] Table 2 Friction coefficient data

[0071] Initial circular saw blade tooth surface 0.53 Comparative Example 1 0.47 Example 1 0.13 Comparative Example 2 0.46 Example 2 0.12 Comparative Example 3 0.44 Example 3 0.14 Comparative Example 4 0.15

[0072] Friction experiments were conducted on the circular saw blade with composite microtexture and lubricating coating on the saw tooth surface of Example 1 and the circular saw blade with electro-jet deposited lubricating coating on the saw tooth surface of Comparative Example 4. The friction conditions were a load of 20 N, a sliding speed of 10 mm / s, and 304 stainless steel balls as the grinding material. The results are shown in Table 3. It can be seen that the composite microtexture on the saw tooth surface can effectively improve the service life of the lubricating coating.

[0073] Table 3. Application time of lubricating coating on circular saw blades in Example 1 and Comparative Example 4.

[0074] Lubricating coating usage time (s) 1800 600

[0075] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a circular saw blade with a composite microtexture and a lubricating coating on the tooth surface, characterized in that, Includes the following steps: A circular saw blade is immersed in a solvent, and a nanosecond laser is used to uniformly process shallow pit microtextures with a depth of 1-5 μm on the surface of the saw teeth. After drying, a deep groove mesh microtexture with a depth of 8-20 μm is processed on the surface of the shallow pit microtextures using a nanosecond laser in air, thus obtaining composite microtextured saw teeth. A lubricating coating is deposited on the surface of the composite microtextured saw teeth by electro-jet deposition, and after drying, it is cured at high temperature to obtain the final product. The groove width of the deep groove mesh microtexture is 20~40 μm, and the groove spacing of the deep groove mesh microtexture is 100~300 μm; The specific steps of electro-jet deposition of a lubricating coating on the surface of the composite microtextured saw teeth are as follows: lubricating material powder and binder are mixed to prepare a lubricating coating solution, and the lubricating coating is deposited on the surface of the composite microtextured saw teeth by electro-jet deposition.

2. The preparation method according to claim 1, characterized in that, The solvent is selected from water or ethanol; the solvent thickness on the surface of the circular saw blade teeth is 1~3mm.

3. The preparation method according to claim 1, characterized in that, In the step of uniformly processing shallow pits with a depth of 1~5μm on the surface of the circular saw blade teeth using a nanosecond laser, the overlap rate of the nanosecond laser processing is 40~60%, the nanosecond laser processing speed is 5~20 mm / s, the nanosecond laser frequency is 150~250 kHz, the nanosecond laser power is 10~30 W, and the number of processing times is 3~6.

4. The preparation method according to claim 1, characterized in that, In the step of processing the shallow pit microtexture surface with a depth of 8~20 μm using a nanosecond laser in air after drying, the nanosecond laser processing frequency is 10~50 kHz, the scanning speed is 100~200 mm / s, the nanosecond laser power is 4~10 W, and the number of processing times is 1~2.

5. The preparation method according to claim 1, characterized in that, The lubricating material powder is selected from one or more of MoS2, WS2, or polytetrafluoroethylene; the binder is selected from one or more of polyamide-imide (PAI) or polyphenylene sulfide (PPS); the solvent of the lubricating coating solution is ethanol; the mass ratio of the lubricating material powder, binder, and solvent is (5~10):(2~5):(20~50); the particle size of the lubricating material powder is 10~100nm.

6. The preparation method according to claim 1, characterized in that, The nozzle moving speed of the electrojet deposition is 6~10 mm / s, the deposition distance is 3~6 mm, the voltage is 2.4~4.0 kV, the number of deposition layers is 8~20, and the thickness of the lubricating coating is 10~20 μm.

7. The preparation method according to claim 1, characterized in that, In the high-temperature curing step after drying, the drying temperature is 60~90℃ and the drying time is 20~60 min; the high-temperature curing temperature is 180~260℃ and the high-temperature curing time is 10~30 min.

8. A circular saw blade with a composite microtexture and a lubricating coating on the saw tooth surface prepared by the preparation method according to any one of claims 1 to 7.

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