Hob cutter ring with multi-scale oxide ceramic composite wear-resistant coating cladded on surface and preparation method of hob cutter ring

Abstract

The invention provides a hobbing cutter ring with a multi-scale oxide ceramic composite wear-resistant coating cladded on the surface and a preparation method of the hobbing cutter ring, and belongs to the technical field of shield tunneling machine equipment. The hobbing cutter ring with the surface cladded with the multi-scale oxide ceramic composite wear-resistant coating comprises a hobbing cutter ring body and the multi-scale oxide ceramic composite wear-resistant coating cladded on the blade and the peripheral surface of the hobbing cutter ring body. The multi-scale oxide ceramic composite wear-resistant coating is composed of nano-scale aluminum oxide ceramic dispersion enhanced NiCoCr-based alloy, small micron-scale ZTA ceramic particles and large micron-scale ZTA ceramic particles. The surface cladding multi-scale oxide ceramic composite wear-resistant coating provided by the invention has the characteristics of no settlement of hard particles, low cost, high wear resistance and the like, and the wear resistance can be remarkably improved, the cutter replacement frequency is reduced and the tunneling efficiency is improved by cladding the surface cladding multi-scale oxide ceramic composite wear-resistant coating on the surface of the hob cutter ring.

Description

Technical Field

[0001] This invention belongs to the field of tunnel boring machine equipment technology, and particularly relates to a cutter ring with a surface cladding of multi-scale oxide ceramic composite wear-resistant coating and its preparation method. Background Technology

[0002] As the teeth of the tunnel boring machine's (TBM) excavation system, the cutterhead directly impacts the excavation face. During rock breaking, the cutterhead must withstand high compressive stress, shear stress, and impact loads. Combined with material fatigue softening due to frictional heating, this accelerates wear and failure, making it one of the main consumables in TBM tunneling. Statistics show that downtime for cutter inspection, replacement, and maintenance due to wear and tear accounts for approximately 30% of the total construction time, and the cost of cutter replacement accounts for approximately 25%-30% of the total construction cost.

[0003] Tunnel boring machine (TBM) cutting tools have stringent material performance requirements, demanding both high strength and toughness, as well as sufficient hardenability, excellent machinability, and good red hardness. Domestic materials scientists have conducted extensive work on improving the material composition ratio, refining cutter ring forming technology, and optimizing heat treatment processes, effectively increasing the market share of domestically produced cutting tools. However, due to the inverse relationship between material strength and toughness, increasing material strength often comes at the cost of decreasing toughness. Therefore, it is difficult to obtain cutting tools that simultaneously possess high strength, high wear resistance, and high toughness simply by improving material composition and optimizing heat treatment processes.

[0004] Surface cladding technology offers significant advantages over other surface strengthening technologies in the areas of surface strengthening, repair, and remanufacturing of critical equipment components. Surface cladding technology uses lasers, plasma, or high-frequency induction as heat sources to simultaneously melt the substrate surface material and the cladding material, which then rapidly solidifies, achieving a metallurgical bond between the coating and the substrate material. Utilizing surface cladding technology to prepare a wear-resistant coating on the surface of cutting tools effectively improves the wear resistance of the tool surface while ensuring the strength and toughness of the tool body. This is the most direct, effective, and economical means to extend the service life of cutting tools.

[0005] The design and proportioning of wear-resistant coating materials fundamentally determine the coating performance. Existing research indicates that among wear-resistant coatings for tool surfaces, composite coating systems consisting of a nickel-based alloy binder phase (such as Ni60 or Ni60A) and tungsten carbide ceramic particles exhibit the best overall wear resistance. However, this coating system still has certain problems. For example, in order to balance the coating's impact resistance and reduce cracking tendency, the content of tungsten carbide ceramic particles in the coating has always been relatively low, failing to fully utilize the wear-resistant effect of the hard particles. In addition, the decomposition and sedimentation of tungsten carbide particles during the cladding process is also a persistent problem in this coating. Finally, the high raw material cost of nickel-based alloy + tungsten carbide coatings limits its widespread application in tunneling tools. Summary of the Invention

[0006] To solve the above-mentioned technical problems, it is necessary to design and develop a new low-cost, high-wear-resistant coating material system and its preparation technology on hobbing cutter rings. Therefore, this invention proposes a hobbing cutter ring with a multi-scale oxide ceramic composite wear-resistant coating and its preparation method. The cutting edge and peripheral surface of the hobbing cutter ring are coated with a composite wear-resistant coating composed of a NiCoCr-based alloy binder phase reinforced by nano-scale alumina ceramic dispersion, small micron-scale ZTA (zirconia-toughened alumina) ceramic particles, and large micron-scale ZTA ceramic particles.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A hob cutter ring with a multi-scale oxide ceramic composite wear-resistant coating fused to its surface includes a hob cutter ring and a multi-scale oxide ceramic composite wear-resistant coating fused to the cutting edge and peripheral surface of the hob cutter ring.

[0009] The multi-scale oxide ceramic composite wear-resistant coating consists of a NiCoCr-based alloy binder phase reinforced by nano-scale alumina ceramic dispersion, small-micron-scale ZTA ceramic particles, and large-micron-scale ZTA ceramic particles.

[0010] The surface cladding multi-scale oxide ceramic composite wear-resistant coating proposed in this invention has the characteristics of hard particles not settling, low cost, and high wear resistance. Laminating it onto the surface of the cutter ring can significantly increase wear resistance, making it widely applicable to tunneling tools, reducing the number of tool changes and improving tunneling efficiency.

[0011] Preferably, the composition of the NiCoCr-based alloy binder phase, by molar percentage, is: 25-30% Co, 25-30% Cr, 2-5% Si, 1-2% B, 0.5-2% C, with the remainder being Ni.

[0012] Preferably, the nano-sized alumina ceramic accounts for 0.5-5% of the volume percentage in the composite wear-resistant coating; the small micron-sized ZTA ceramic particles account for 2-10% of the volume percentage in the composite wear-resistant coating; the large micron-sized ZTA ceramic particles account for 35-50% of the volume percentage in the composite wear-resistant coating, and the remainder is a NiCoCr-based alloy.

[0013] Preferably, the particle size of the nano-sized alumina ceramic is 30-50 nm; the particle size of the small micron-sized ZTA ceramic particles is 2-5 μm; and the particle size of the large micron-sized ZTA ceramic particles is 100-300 μm.

[0014] A method for preparing a hobbing cutter ring with a surface cladding multi-scale oxide ceramic composite wear-resistant coating includes the following steps:

[0015] Weigh each ingredient accurately according to the proportions;

[0016] First, nano-alumina powder is placed in an alumina ball mill jar containing a process control agent and dispersed by ultrasonic vibration. Then, NiCoCr-based alloy powder is placed in the ball mill jar and ball milled.

[0017] Dry the ball-milled alloy powder;

[0018] The dried alloy powder, small-micron ZTA ceramic particles and large-micron ZTA ceramic particles are put into a low-speed mixer and mixed for 2-5 hours to obtain the coating powder.

[0019] Mix the coating powder with water glass to form a paste, and apply it evenly to the blade and perimeter of the roller cutter ring that has been sandblasted. The pre-coating thickness is 2-4mm. First, dry it in the air for 30 minutes, and then put it in a drying oven at 100-150℃ for 8-12 hours.

[0020] The dried pre-coated layer is then subjected to plasma beam scanning to obtain a hobbing cutter ring with a multi-scale oxide ceramic composite wear-resistant coating fused to its surface.

[0021] Preferably, the process control agent is anhydrous ethanol;

[0022] The ultrasonic vibration dispersion time is 5-20 minutes;

[0023] The ball milling speed is 300-400 r / min, and the time is 10-20 hours;

[0024] The drying time for the ball-milled alloy powder is 12-24 hours, and the drying temperature is 60-80℃.

[0025] Preferably, the NiCoCr-based alloy powder is an alloy powder prepared by vacuum atomization, with a particle size of 20-100 μm.

[0026] Preferably, the water glass accounts for 3-8% of the mass fraction of the mixed coating powder, and the modulus of the water glass is 3.0-3.5.

[0027] Preferred process parameters for plasma beam scanning are: operating current 110-140A, nozzle height 20-25mm, cladding speed 40-60mm / min, plasma arc oscillation width 15-35mm, inert gas protection, and ion gas flow rate 0.2-0.4L / min.

[0028] Compared with the prior art, the present invention has the following advantages and technical effects:

[0029] Compared to other ceramic wear-resistant coating technologies, this invention uses low-cost, low-density, and high thermal stability alumina (3.5 g / cm³). 3 ) and zirconia-toughened alumina ZTA (4.3 g / cm) 3 ) to replace tungsten carbide (15.63 g / cm) 3 This solves the problem of hard wear-resistant particles settling and decomposing during the coating cladding process, thus ensuring the overall wear resistance of the coating.

[0030] Furthermore, the coating binder phase in this invention is a novel NiCoCr-based medium-entropy alloy, which has excellent strength-plasticity matching. Based on this, this invention adds appropriate amounts of silicon and boron elements to improve its cladding processability.

[0031] Finally, the hard ceramic particles added in this invention are multi-scale, including nano-sized, small-micron-sized alumina ceramic particles, and large-micron-sized ZTA ceramic particles. Each of these multi-scale particles plays a specific role, giving the coating excellent overall wear resistance. The nano-alumina particles are dispersed within the NiCoCr-based medium-entropy alloy binder phase matrix, acting as dispersion reinforcement and improving the strength of the binder phase. The small-micron-sized ZTA ceramic particle composite coating exhibits excellent performance under static wear conditions, while the large-micron-sized ZTA ceramic particle composite coating possesses certain impact resistance and self-sharpening capabilities. Furthermore, the nano-alumina particles are added by high-energy ball milling and mixing, adhering them to the NiCoCr alloy powder, without requiring any binders, fluids, or chemical reactions. Attached Figure Description

[0032] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0033] Figure 1 This is a SEM image of the upper part of the cross-section of the multi-scale oxide ceramic composite wear-resistant coating in Example 1;

[0034] Figure 2 This is a photograph of a hob cutter ring with a multi-scale oxide ceramic composite wear-resistant coating fused to its surface.

[0035] Figure 3 The image shows the upper part of the cross-section of the tungsten carbide ceramic composite wear-resistant coating in Comparative Example 1. Detailed Implementation

[0036] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0037] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0038] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0039] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0040] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0041] All raw materials used in the embodiments of this invention were obtained through commercial purchase.

[0042] The technical solution of the present invention will be further illustrated by the following embodiments.

[0043] Example 1

[0044] A hob cutter ring with a multi-scale oxide ceramic composite wear-resistant coating is disclosed. The cutting edge and surrounding surface of the hob cutter ring are coated with a composite wear-resistant coating composed of a NiCoCr-based alloy reinforced by nano-scale alumina ceramic dispersion, small-micron-scale ZTA ceramic particles, and large-micron-scale ZTA ceramic particles. The preparation steps are as follows:

[0045] First, weigh out NiCoCr-based alloy powder, nano-sized alumina ceramic powder, small-micron ZTA ceramic particles, and large-micron ZTA ceramic particles according to a volume ratio of 40:5:10:45 for later use. The NiCoCr-based alloy has the following composition by molar percentage: 25% Co, 30% Cr, 5% Si, 2% B, 1.5% C, and the remainder is Ni. The nano-sized alumina ceramic has a particle size of 30-50 nm, the small-micron ZTA ceramic particles have a particle size of 2-5 μm, and the large-micron ZTA ceramic particles have a particle size of 100-300 μm.

[0046] First, nano-sized alumina powder was placed in an alumina ball mill jar containing anhydrous ethanol as a process control agent and dispersed by ultrasonic vibration for 20 minutes. Then, NiCoCr-based alloy powder was placed in the ball mill jar and ball milled at a speed of 400 r / min for 15 hours.

[0047] The ball-milled powder was placed in a drying oven and dried for 12 hours at a temperature of 80°C.

[0048] The dried alloy powder, small micron-sized ZTA ceramic particles and large micron-sized ZTA ceramic particles are put into a low-speed mixer and mixed for 4 hours to obtain the coating powder.

[0049] Add 5% by mass of water glass with a modulus of 3.0-3.5 to the mixed coating powder to make a paste, and apply it evenly to the cutting edge and perimeter of the roller cutter ring after surface sandblasting. The pre-coating thickness is 3mm. First, dry it in the air for 30 minutes, and then put it in a drying oven at 120℃ for 8 hours.

[0050] The dried pre-coated layer was then subjected to plasma beam scanning. The process parameters for plasma beam scanning were: operating current 130A, nozzle height 20mm, cladding speed 50mm / min, plasma arc oscillation width 20mm, inert gas protection, and ion gas flow rate 0.3L / min. Under the scanning of the plasma beam, the pre-coated layer fused together with the cutting edge and surrounding surface of the hobbing cutter ring, thus obtaining a hobbing cutter ring with a multi-scale oxide ceramic composite wear-resistant coating clad on its surface.

[0051] SEM image of the upper part of the cross section of the multi-scale oxide ceramic composite wear-resistant coating, as shown below. Figure 1 As shown, small-micron and large-micron ZTA ceramic particles are uniformly distributed on the upper part of the coating, without any particle sedimentation, and are completely encapsulated by the NiCoCr-based alloy binder phase.

[0052] The hardness of the coating was tested using a Wilson VH1102 microhardness tester manufactured by BUEHLER. The applied load of the microhardness tester was 100g, and the load holding time was 10s. The average hardness of the coating was measured to be 1200-1400HV. The coating sample was tested by pendulum impact test. The impact energy of the coating was 135J, which showed good hardness and toughness matching ability.

[0053] See the physical image of the hob cutter ring with a multi-scale oxide ceramic composite wear-resistant coating. Figure 2 In the Xugang Hospital Station-Xiadian Station section of the Xuzhou Urban Rail Transit Line 3 Phase II project, the coated cutterhead rings were installed and replaced simultaneously with the uncoated cutterheads at the side cutter positions of the tunnel boring machine cutterhead. According to statistics, after installation, the cutterhead tunneled 229 rings to exit the tunnel. The coated cutterheads did not need to be replaced, and their performance was significantly better than the uncoated cutterheads. Furthermore, the cutterhead rings wore evenly without any chipping.

[0054] Example 2

[0055] First, weigh out NiCoCr-based alloy powder, nano-sized alumina ceramic powder, small-micron ZTA ceramic particles, and large-micron ZTA ceramic particles according to a volume ratio of 48:2:5:45. The NiCoCr-based alloy has the following composition by molar percentage: 28% Co, 28% Cr, 4% Si, 2% B, 1% C, and the remainder is Ni. The nano-sized alumina ceramic has a particle size of 30-50 nm, the small-micron ZTA ceramic particles have a particle size of 2-5 μm, and the large-micron ZTA ceramic particles have a particle size of 100-300 μm.

[0056] First, nano-sized alumina powder was placed in an alumina ball mill jar containing anhydrous ethanol as a process control agent and dispersed by ultrasonic vibration for 20 minutes. Then, NiCoCr-based alloy powder was placed in the ball mill jar and ball milled at a speed of 400 r / min for 15 hours.

[0057] The ball-milled powder was placed in a drying oven and dried for 12 hours at a temperature of 80°C.

[0058] The dried alloy powder, small micron-sized ZTA ceramic particles and large micron-sized ZTA ceramic particles are put into a low-speed mixer and mixed for 4 hours to obtain the coating powder.

[0059] Add 5% by mass of water glass with a modulus of 3.0-3.5 to the mixed coating powder to make a paste, and apply it evenly to the cutting edge and perimeter of the roller cutter ring after surface sandblasting. The pre-coating thickness is 3mm. First, dry it in the air for 30 minutes, and then put it in a drying oven at 120℃ for 8 hours.

[0060] The dried pre-coated layer was then subjected to plasma beam scanning. The process parameters for plasma beam scanning were: operating current 125A, nozzle height 20mm, cladding speed 45mm / min, plasma arc oscillation width 20mm, inert gas protection, and ion gas flow rate 0.3L / min. Under the scanning of the plasma beam, the pre-coated layer fused together with the cutting edge and surrounding surface of the hobbing cutter ring, thus obtaining a hobbing cutter ring with a multi-scale oxide ceramic composite wear-resistant coating clad on its surface.

[0061] Comparative Example 1

[0062] Similar to Example 1, except that spherical tungsten carbide ceramic particles (50-100 μm in size) are used instead of multi-scale oxide ceramic particles. These particles are mixed with NiCoCr-based alloy powder at a weight ratio of 60:40, slurryed, and coated into a pre-formed layer. The tungsten carbide ceramic composite coating is obtained by scanning with a plasma beam. Figure 3 The image shown is a SEM image of the upper part of the cross-section of the tungsten carbide ceramic composite wear-resistant coating. It can be seen that the tungsten carbide particles have undergone obvious deposition and decomposition, resulting in a reduction in the number of hard particles on the upper part of the coating and insufficient wear resistance.

[0063] Comparative Example 2

[0064] Similar to Example 1, except that silicon and boron were not added during the preparation of the NiCoCr-based alloy powder. The NiCoCr-based alloy composition, by molar percentage, was: 30% Co, 30% Cr, 1.5% C, with the remainder being Ni. The method for preparing the hobbing cutter ring with a surface-clad multi-scale oxide ceramic composite wear-resistant coating using this NiCoCr-based alloy powder was the same as in Example 1. Results showed that under the same plasma beam scanning conditions, the wettability of the molten pool decreased during the coating cladding process, and obvious defects such as flow lines and pores appeared on the coating surface, resulting in poor cladding quality and failure to form the desired shape.

[0065] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A hobbing cutter ring with a surface clad with a multi-scale oxide ceramic composite wear-resistant coating, characterized in that, This includes a hob cutter ring and a multi-scale oxide ceramic composite wear-resistant coating fused to the cutting edge and peripheral surface of the hob cutter ring; The multi-scale oxide ceramic composite wear-resistant coating is composed of a NiCoCr-based alloy reinforced by nano-alumina ceramic dispersion, small-micron ZTA ceramic particles, and large-micron ZTA ceramic particles.

2. The hobbing cutter ring with a surface cladding multi-scale oxide ceramic composite wear-resistant coating according to claim 1, characterized in that, The composition of the NiCoCr-based alloy, by molar percentage, is: 25-30% Co, 25-30% Cr, 2-5% Si, 1-2% B, 0.5-2% C, with the remainder being Ni.

3. The hobbing cutter ring with a surface cladding multi-scale oxide ceramic composite wear-resistant coating according to claim 1, characterized in that, The nano-sized alumina ceramic accounts for 0.5-5% of the volume in the composite wear-resistant coating; the small micron-sized ZTA ceramic particles account for 2-10% of the volume in the composite wear-resistant coating; the large micron-sized ZTA ceramic particles account for 35-50% of the volume in the composite wear-resistant coating, with the remainder being NiCoCr-based alloys.

4. The hobbing cutter ring with a surface-clad multi-scale oxide ceramic composite wear-resistant coating according to claim 3, characterized in that, The nano-sized alumina ceramic has a particle size of 30-50 nm; the small micron-sized ZTA ceramic particles have a particle size of 2-5 μm; and the large micron-sized ZTA ceramic particles have a particle size of 100-300 μm.

5. A method for preparing a hobbing cutter ring with a surface-clad multi-scale oxide ceramic composite wear-resistant coating as described in any one of claims 1-4, characterized in that, Includes the following steps: Weigh each raw material according to the proportions; First, nano-alumina powder is placed in a ball mill jar containing a process control agent and dispersed by ultrasonic vibration. Then, NiCoCr-based alloy powder is placed in the ball mill jar and ball milled. Dry the ball-milled alloy powder; The dried alloy powder, small-micron ZTA ceramic particles and large-micron ZTA ceramic particles are put into a low-speed mixer and mixed to obtain the coating powder. Mix the coating powder with water glass to form a paste, and apply it evenly to the blade and perimeter of the roller cutter ring that has been sandblasted. The pre-coating thickness is 2-4mm. First, dry it in the air for 30 minutes, and then put it in a drying oven at 100-150℃ for 8-12 hours. The dried pre-coated layer is then subjected to plasma beam scanning to obtain a hobbing cutter ring with a multi-scale oxide ceramic composite wear-resistant coating fused to its surface.

6. The method for preparing a hobbing cutter ring with a surface-clad multi-scale oxide ceramic composite wear-resistant coating according to claim 5, characterized in that, The process control agent is anhydrous ethanol; The ultrasonic vibration dispersion time is 5-20 minutes; The ball milling speed is 300-400 r / min, and the time is 10-20 hours; The drying time for the ball-milled alloy powder is 12-24 hours, and the drying temperature is 60-80℃.

7. The method for preparing a hobbing cutter ring with a surface-clad multi-scale oxide ceramic composite wear-resistant coating according to claim 5, characterized in that, The NiCoCr-based alloy powder is an alloy powder prepared by vacuum atomization, with a particle size of 20-100 μm.

8. The method for preparing a hobbing cutter ring with a surface-clad multi-scale oxide ceramic composite wear-resistant coating according to claim 5, characterized in that, The water glass accounts for 3-8% of the mass fraction of the mixed coating powder, and the modulus of the water glass is 3.0-3.

5.

9. The method for preparing a hobbing cutter ring with a surface-clad multi-scale oxide ceramic composite wear-resistant coating according to claim 5, characterized in that, The process parameters for plasma beam scanning are as follows: operating current 110-140A, nozzle height 20-25mm, cladding speed 40-60mm / min, plasma arc oscillation width 15-35mm, inert gas protection, and ion gas flow rate 0.2-0.4L / min.

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