A laser cladding method for improving service life of a vibrating tool by using an alloy coating

Abstract

The application belongs to the technical field of vibrating tools, and particularly relates to a laser cladding method for prolonging the service life of vibrating tools by alloy coating, which comprises an alloy powder as the material of the alloy coating processed by laser cladding technology, and the chemical composition of the alloy powder is shown as follows: C: 0.29-0.31wt%; Cr: 8.04-8.33wt%; Co: 11.90-12.20wt%; Mn: 6.76-6.85wt%; Ni-coated W-Ti-C: 6.55-6.90wt%; Si: 0.67-0.79wt%; and Fe is the balance. The application realizes the strengthening target of the metallurgical coating of small vibrating tools by the small laser heat deformation. Especially, the combined action of Mn and Co elements is utilized to manufacture the toughened structure mainly composed of martensite and austenite, so that the problems of poor wear resistance and tool breakage of vibrating tools are avoided. The Mn element is added, and the tool will be more wear-resistant during the tool wear process, thereby prolonging the service life of the tool. The solution provided by the application not only avoids the industry pain points such as poor wear resistance and tool breakage in the prior art, but also uses the low-cost Fe-based alloy powder without replacing the tool body material.

Description

Technical Field

[0001] This invention belongs to the field of vibratory cutting tool technology, specifically relating to a laser cladding method for improving the service life of vibratory cutting tools by utilizing alloy coatings. Background Technology

[0002] Vibrating cutters are commonly used cutting tools in the garment industry. When cutting fabric, these cutters can travel at speeds of hundreds of meters per minute, cutting fabrics ranging from tens of millimeters in thickness. Due to their small size—the blade is only 3mm thick and 8mm at its widest point—the blades are prone to wear and breakage, especially in environments with varying fabric hardness. To address this industry problem, some have attempted to replace the base material of the cutter (which is usually ordinary structural steel) with high-speed steel and use overall heat treatment. However, this approach has been slow to gain traction due to high costs and limited improvement in the breakage problem. Others have tried nitriding, overall quenching of the cutter base material, and surface cold hardening to address the industry's pain points, but the inherent contradiction between wear resistance and chipping remains unresolved.

[0003] Laser cladding technology has a natural advantage for machining small workpieces, especially small cutting tools, due to its minimal thermal deformation.

[0004] Chinese patent CN103334102A discloses a "cobalt-based cermet alloy powder specifically for laser cladding of guillotines." According to the technical solution provided in this patent, "4-6% calcium fluoride and 1-3% silicon nitride" are added to the cobalt alloy powder. Based on the fundamental principle of "like dissolves like" in materials science, if such semi-ceramic or pure ceramic materials are not coated with elements similar to the base metal, they are difficult to dissolve in cobalt-based metals and form a complete metal coating. This also means that the cladding layer of this type of material is prone to pores and inclusions, leading to failure of the metal's impact resistance and frequent tool breakage. Furthermore, cobalt-based alloy powder is expensive and is considered a strategic reserve material for countries; its large-scale application in vibrating cutting tools is clearly inappropriate.

[0005] Chinese patent CN117305830A discloses a "method for preparing kitchen knives using laser cladding based on powdered high-entropy alloy steel and the resulting kitchen knife." The material solution provided in this patent involves a high-entropy alloy coating applied to a kitchen environment, where antibacterial capabilities are crucial. Kitchen knives, unlike vibrating knives, do not withstand the same level of wear and impact. Therefore, a high content of Cr and multi-element alloys for reinforcement are unnecessary. Due to the different operating conditions, this solution cannot be applied to vibrating knives. Furthermore, this patent application pertains to Fe-based alloy powder, a single matrix phase material dominated by Fe, which is not the high-entropy multi-element alloy material described in this patent. Summary of the Invention

[0006] The purpose of this invention is to provide a laser cladding method for improving the service life of vibrating cutting tools using alloy coatings. This addresses the problem encountered when using a rib scanner for flaw detection, where the operator holds the scanner by its handle and places the probe against the rib surface. However, due to the common unique structures on rib surfaces such as ripples, ribs, unevenness, or localized rust protrusions, traditional rib scanners with fixed wheels are prone to probe suspension or partial detachment during mobile scanning, failing to maintain a tight fit with the rib surface. This poor fit directly leads to unstable electromagnetic signal acquisition, missing or distorted data sampling points, resulting in serious deviations in the location and assessment of internal rib damage (such as cracks, rust, and fractures). The accuracy and reliability of the detection results are significantly reduced, affecting engineering quality assessment and potentially creating safety hazards due to missed or misjudged detections, increasing subsequent maintenance and reinforcement costs.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a laser cladding method for improving the service life of vibrating cutting tools using an alloy coating, comprising an alloy powder as the material of the alloy coating processed by laser cladding technology, the chemical composition of which is as follows: C: 0.29~0.31wt% Cr: 8.04~8.33wt%; Co: 11.90~12.20wt% Mn: 6.76~6.85wt% Ni-packaged W-Ti-C: 6.55~6.90 wt%; Si: 0.67~0.79wt% Fe is the balance.

[0008] The "Ni-coated W-Ti-C" alloy powder used in the aforementioned laser cladding technology is obtained by separate powder preparation, with a particle size of 4~8μm. It is then mechanically mixed into the Fe-based alloy powder. The laser cladding operation on A8 steel plates using the aforementioned alloy powder is as follows: Step 1, Linear Cladding: Select a fiber laser with a φ3mm circular spot size and a power of 3800~4000w, a single-sided cladding thickness of 4.1~4.5mm, and a linear velocity of 4.2~4.6mm / s; after setting the parameters, perform single-line cladding. Step 2, heat treatment method: Place the workpiece with linear cladding completed in step 1 into an electric resistance furnace and heat it to 370±10℃ at a rate of 14.5~15.5℃ / min. Hold it at that temperature for 18±2min, then remove it from the furnace and air cool it to obtain an alloy coating with no cracks, a hardness of 60±0.5HRC, and metallurgical bonding.

[0009] To ensure stable movement, in the preferred embodiment of the laser cladding method for improving the service life of vibrating tools using alloy coatings according to the present invention, the proportion of Ni element in the "Ni-coated W-Ti-C" alloy powder is 8.39~9.26wt%; C: 7.98~8.05wt%; Ti: 21.77~21.98wt%; with the balance being W. The alloy coating has a martensitic + austenitic dual-phase structure, with a martensite content of 50-90% and a retained austenite content of 10-50%. The Mn and Co work together to regulate the martensitic phase transformation temperature: Mn lowers the Ms point and Co raises the Ms point, so that the coating can simultaneously satisfy high hardness and high impact toughness. The Ni-coated W-Ti-C is distributed as a dispersed hard phase. The Ni coating layer solves the problem of poor wettability between carbides and Fe matrix, and eliminates interfacial pores and inclusions. The Ni-coated W-Ti-C is distributed as a dispersed hard phase. The Ni coating layer solves the problem of poor wettability between carbides and the Fe matrix, eliminates interfacial pores and inclusions, and the Si element deoxidizes and forms slag, so that the density of the cladding layer is ≥99.5% and there are no oxide inclusion defects.

[0010] Compared with the prior art, the beneficial effects of the present invention are: This invention leverages the minimal thermal deformation characteristic of lasers to achieve the strengthening goal of a "metallurgical coating" for small vibrating cutting tools. In particular, by utilizing the combined effect of Mn and Co elements, a strong and tough microstructure dominated by "martensite + austenite" is created, avoiding the problems of wear resistance and tool breakage in vibrating cutting tools.

[0011] Furthermore, due to the addition of Mn, the tool becomes more wear-resistant as it wears, which will further extend the tool's service life.

[0012] In summary, the solution provided by this invention not only avoids industry pain points such as poor wear resistance and tool breakage in existing technologies, but also protects cost by using low-cost Fe-based alloy powder without changing the tool body material. Attached Figure Description

[0013] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1The solution provided in the embodiment of the present invention calculates the phase transformation diagram of the Fe matrix phase in the cladding layer. Martensitestart is the temperature at which the martensitic phase transformation begins; Martensite 50% is the temperature at which 50% of the martensitic phase transformation is completed; Martensite 90% is the temperature at which 90% of the martensitic phase transformation is completed; 53 is the hardness value: 53 HRC.

[0014] Figure 2 A schematic diagram of the heat treatment process for wood chipper blades manufactured to provide a solution for this invention.

[0015] Figure 3 This is a schematic diagram of the hardness of the cladding layer of the vibrating tool tested according to the present invention. In the figure: LIQUID is the liquid phase; AUSTENITE is the austenitic phase; M7C3 and M23C6 are metal carbide phases; FERRITE is the ferrite phase. Detailed Implementation

[0016] The technical solutions of 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.

[0017] Please see Figure 1-3 The present invention provides the following technical solution: a laser cladding method for improving the service life of vibrating cutting tools by utilizing an alloy coating, comprising an alloy powder as the material for the alloy coating processed by laser cladding technology, the chemical composition of which is as follows: C: 0.29~0.31wt% Cr: 8.04~8.33wt%; Co: 11.90~12.20wt% Mn: 6.76~6.85wt% Ni-packaged W-Ti-C: 6.55~6.90 wt%; Si: 0.67~0.79wt% Fe is the balance.

[0018] The "Ni-coated W-Ti-C" alloy powder used in the aforementioned laser cladding technology is obtained by separate powder preparation, with a particle size of 4~8μm. It is then mechanically mixed into the Fe-based alloy powder. The laser cladding operation on A8 steel plates using the aforementioned alloy powder is as follows: Step 1, Linear Cladding: Select a fiber laser with a φ3mm circular spot size and a power of 3800~4000w, a single-sided cladding thickness of 4.1~4.5mm, and a linear velocity of 4.2~4.6mm / s; after setting the parameters, perform single-line cladding. Step 2, heat treatment method: Place the workpiece with linear cladding completed in step 1 into an electric resistance furnace and heat it to 370±10℃ at a rate of 14.5~15.5℃ / min. Hold it at that temperature for 18±2min, then remove it from the furnace and air cool it to obtain an alloy coating with no cracks, a hardness of 60±0.5HRC, and metallurgical bonding.

[0019] Preferably, in the “Ni-coated W-Ti-C” alloy powder, the proportion of Ni element is 8.39~9.26wt%; C: 7.98~8.05wt%; Ti: 21.77~21.98wt%; and the balance is W. The alloy coating has a martensitic + austenitic dual-phase structure, with a martensite content of 50-90% and a retained austenite content of 10-50%. The Mn and Co work together to regulate the martensitic phase transformation temperature: Mn lowers the Ms point and Co raises the Ms point, so that the coating can simultaneously satisfy high hardness and high impact toughness. The Ni-coated W-Ti-C is distributed as a dispersed hard phase. The Ni coating layer solves the problem of poor wettability between carbides and Fe matrix, and eliminates interfacial pores and inclusions. The Ni-coated W-Ti-C is distributed as a dispersed hard phase. The Ni coating layer solves the problem of poor wettability between carbides and the Fe matrix, eliminates interfacial pores and inclusions, and the Si element deoxidizes and forms slag, so that the density of the cladding layer is ≥99.5% and there are no oxide inclusion defects.

[0020] The combined use of C and Cr elements provides a basic hardness guarantee for the cutting tool and improves the hardenability of the cladding. The target hardness of the laser cladding layer is 60±0.5 HRC, and the cladding layer must be free of porosity and cracks. Furthermore, the addition of Cr increases the ferrite phase content, thereby increasing the toughness and crack resistance of the Fe-based matrix phase. Therefore, the target content is medium carbon and low chromium to balance hardness and the formation of defects such as cracks. Thus, the optimal C and Cr content is 0.29~0.31 wt% and 8.04~8.33 wt%, respectively. The combined use of Mn and Co elements creates a strong and tough matrix structure in the cladding layer, primarily composed of martensite and austenite. This helps prevent tool wear and breakage. However, when the Co content is below 11.90 wt%, the residual austenite in the cladding layer is too high, which is detrimental to the tool's hardness and wear resistance. When the Co content is above 12.20 wt%, the martensitic phase content in the cladding layer is too high, making the tool prone to chipping and breakage. Conversely, when the Mn content is above 6.85 wt%, the residual austenite in the cladding layer is too high, which is also detrimental to the tool's hardness and wear resistance. When the Mn content is below 6.76 wt%, the martensitic phase content in the cladding layer is too high, making the tool prone to chipping and breakage. The "Ni-coated W-Ti-C" powder (phase) is used because the hardness of the Fe-based matrix phase is insufficient to improve the overall performance of the cladding layer. While not "severing" the Fe-based matrix phase, a fine "Ni-coated W-Ti-C" hard phase is added to improve the toughness and wear resistance of the cladding layer through "dispersion and refinement." Ni mainly acts as a "bridge" between the powder and the cladding layer to avoid cladding defects. The addition of W is for improved wear resistance, while the addition of the strong carbide element Ti provides a "stabilizer" effect for the "Ni-coated W-Ti-C" hard phase, inhibiting the decomposition of WC. When the "Ni-coated W-Ti-C" powder content is below 6.55 wt%, the hardness and wear resistance of the cladding layer are insufficient; when the "Ni-coated W-Ti-C" powder content is above 6.90 wt%, the cladding layer has a high tendency to crack. Si (silicon) helps remove oxygen and form slag, which is beneficial for the formation of laser alloy layers. The optimal Si content for cladding is between 0.70 and 0.80 wt%. Excessive Si content can lead to slag inclusions in the cladding layer. Conversely, content below the lower limit of the specified value will result in incomplete removal of oxygen, causing cladding defects. The Fe element is chosen based on cost and the compatibility between the alloy powder and the substrate. Example

[0021] 1. A laser cladding method for improving the service life of vibrating cutting tools by utilizing alloy coatings, wherein the alloy coating material processed by laser cladding technology is alloy powder with the following chemical composition: C: 0.29wt%; Cr: 8.04wt%; Co: 11.90 wt%; Mn: 6.76 wt%; Ni-coated W-Ti-C: 6.55 wt%; Si: 0.67 wt%; Fe: balance. The "Ni-coated W-Ti-C" alloy powder used in the aforementioned laser cladding technology is obtained by separate powder preparation, with a particle size of 4-8 μm. It is then mechanically mixed into the Fe-based alloy powder.

[0022] In the aforementioned "Ni-W-Ti-C" alloy powder, Ni accounts for 8.39 wt%; C accounts for 7.98 wt%; Ti accounts for 21.77 wt%; and the balance is W.

[0023] Laser cladding is performed on A8 steel plates: a fiber laser with a spot size of φ3mm and a power of 3800w is selected, the cladding thickness on one side is 4.1mm, and the linear velocity is 4.2mm / s; after the parameters are set, a single straight line cladding is performed.

[0024] The workpiece is placed in an electric resistance furnace and heated to 360°C at a rate of 14.5°C / min, held at that temperature for 16 minutes, and then removed from the furnace and air-cooled.

[0025] The vibratory tool prepared in this way showed no cracks during flaw detection, and the hardness of the cladding layer was tested to be 59.6 HRC. Example

[0026] 1. A laser cladding method for improving the service life of vibrating cutting tools by utilizing alloy coatings, wherein the alloy coating material processed by laser cladding technology is alloy powder with the following chemical composition: C: 0.31wt%; Cr: 8.33wt%; Co: 12.20 wt%; Mn: 6.85 wt%; Ni-coated W-Ti-C: 6.90 wt%; Si: 0.79 wt%; Fe as the balance. The "Ni-coated W-Ti-C" alloy powder used in the aforementioned laser cladding technology is obtained by separate powder preparation, with a particle size of 4~8 μm. It is then mechanically mixed into the Fe-based alloy powder.

[0027] In the aforementioned "Ni-W-Ti-C" alloy powder, the proportion of Ni is 9.26 wt%; the proportion of C is 8.05 wt%; the proportion of Ti is 21.98 wt%; and the balance is W.

[0028] Laser cladding is performed on A8 steel plates: a fiber laser with a spot size of φ3mm and a power of 4000w is selected, the cladding thickness on one side is 4.5mm, and the linear velocity is 4.6mm / s; after the parameters are set, a single straight line cladding is performed.

[0029] The workpiece is placed in an electric resistance furnace and heated to 380°C at a rate of 15.5°C / min, held at that temperature for 20 minutes, and then removed from the furnace and air-cooled.

[0030] The vibratory tool prepared in this way showed no cracks during flaw detection, and the hardness of the cladding layer was tested to be 60.3 HRC. Example

[0031] 1. A laser cladding method for improving the service life of vibrating cutting tools by utilizing alloy coatings, wherein the alloy coating material processed by laser cladding technology is alloy powder with the following chemical composition: C: 0.30wt%; Cr: 8.19wt%; Co: 12.05wt%; Mn: 6.80wt%; Ni-coated W-Ti-C: 6.73wt%; Si: 0.74wt%; Fe: balance. The "Ni-coated W-Ti-C" alloy powder used in the aforementioned laser cladding technology is obtained by separate powder preparation, with a particle size of 4~8μm. It is then mechanically mixed into the Fe-based alloy powder.

[0032] In the aforementioned "Ni-W-Ti-C" alloy powder, the proportion of Ni is 8.83 wt%; the proportion of C is 8.01 wt%; the proportion of Ti is 21.87 wt%; and the balance is W.

[0033] Laser cladding is performed on A8 steel plates: a fiber laser with a spot size of φ3mm and a power of 3900w is selected, the cladding thickness on one side is 4.3mm, and the linear velocity is 4.4mm / s; after the parameters are set, a single straight line cladding is performed.

[0034] The workpiece is placed in an electric resistance furnace and heated to 370°C at a rate of 15.0°C / min, held at that temperature for 18 minutes, and then removed from the furnace and air-cooled.

[0035] The vibratory tool prepared in this way showed no cracks during flaw detection, and the hardness of the cladding layer was tested to be 60.1 HRC.

[0036] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A laser cladding method for improving the service life of vibrating cutting tools using alloy coatings, characterized in that, The materials used for alloy coatings processed using laser cladding technology are alloy powders, and their chemical composition is as follows: C: 0.29~0.31wt%; Cr: 8.04~8.33wt% Co: 11.90~12.20wt% Mn: 6.76~6.85wt% Ni-packaged W-Ti-C: 6.55~6.90 wt%; Si: 0.67~0.79wt% Fe is the balance; The laser cladding operation on A8 steel plates using the aforementioned alloy powder is as follows: Step 1, Linear Cladding: Select a fiber laser with a φ3mm circular spot size and a power of 3800~4000w, a single-sided cladding thickness of 4.1~4.5mm, and a linear velocity of 4.2~4.6mm / s; after setting the parameters, perform single-line cladding. Step 2, heat treatment method: Place the workpiece with linear cladding completed in step 1 into an electric resistance furnace and heat it to 370±10℃ at a rate of 14.5~15.5℃ / min. Hold it at that temperature for 18±2min, then remove it from the furnace and air cool it to obtain an alloy coating with no cracks, a hardness of 60±0.5HRC, and metallurgical bonding.

2. The laser cladding method for improving the service life of vibrating cutting tools using alloy coatings according to claim 1, characterized in that: The "Ni-coated W-Ti-C" in the alloy powder is obtained by separate powdering, with a particle size of 4~8μm. It is then added to the Fe-based alloy powder by mechanical mixing.

3. The laser cladding method for improving the service life of vibrating cutting tools using alloy coatings according to claim 1, characterized in that: The Ni-coated W-Ti-C alloy powder contains Ni at a concentration of 8.39-9.26 wt%. C: 7.98~8.05wt%, Ti: 21.77~21.98wt%, balance W.

4. The laser cladding method for improving the service life of vibrating cutting tools using alloy coatings according to claim 1, characterized in that: The alloy coating has a martensitic + austenitic dual-phase structure, with a martensite content of 50-90% and a retained austenite content of 10-50%.

5. The laser cladding method for improving the service life of vibrating cutting tools using alloy coatings according to claim 1, characterized in that: The Mn and Co work together to regulate the martensitic phase transformation temperature: Mn lowers the Ms point and Co raises the Ms point, so that the coating can simultaneously satisfy high hardness and high impact toughness.

6. The laser cladding method for improving the service life of vibrating cutting tools using alloy coatings according to claim 1, characterized in that: The Ni-coated W-Ti-C is distributed as a dispersed hard phase. The Ni coating layer solves the problem of poor wettability between carbides and the Fe matrix, and eliminates interfacial pores and inclusions.

7. The laser cladding method for improving the service life of vibrating cutting tools using alloy coatings according to claim 1, characterized in that: The Ni-coated W-Ti-C is distributed as a dispersed hard phase. The Ni coating layer solves the problem of poor wettability between carbides and the Fe matrix, eliminates interfacial pores and inclusions, and the Si element deoxidizes and forms slag, so that the density of the cladding layer is ≥99.5% and there are no oxide inclusion defects.

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