A cutter ring gradient composite cladding coating suitable for extremely hard rock working conditions and a forming method thereof

Abstract

This invention discloses a gradient composite cladding coating for cutter rings suitable for extremely hard rock conditions and its forming method, relating to the field of tunnel boring equipment. It constructs a coating layer consisting of, from the cutter ring substrate outwards, a gradient composite cladding coating... Ni Base interface adaptation layer FeCoCrNi -nanometer WC tough and rigid synergy layer NiCoCrMo A three-layer gradient composite cladding coating for wear-resistant and impact-resistant multiphase ceramics avoids the abrupt performance changes between traditional single-layer coatings and the substrate through a performance gradient. This process employs laser cladding to construct the coating layer by layer, simultaneously coupled with an ultrasonic rolling-assisted process. The laser energy is adjusted to create a gradient adaptation mechanism based on the material properties of each layer. High-frequency ultrasonic vibration is applied online to refine the grains and reduce porosity. Finally, tempering heat treatment releases residual stress, resulting in a final coating surface microhardness ≥1000. HV Bond strength ≥200 MPa With a porosity of ≤1%, impact fatigue resistance is improved by ≥50%, and service life is increased by 2-3 times compared to traditional cutter rings, providing technical support for enhancing the extreme environment performance of TBM (Tunnel Boring Machine) cutter rings.

Description

Technical Field

[0001] This invention belongs to the technical field of TBM tool surface strengthening and tunnel boring equipment. Specifically, it is a tool ring gradient composite cladding coating and forming method suitable for extremely hard rock conditions such as ultra-deep seabed tunnels and hard rock formations. Background Technology

[0002] As the core equipment in tunnel boring machine (TBM) engineering, the cutterhead directly contacts the ground. In extremely hard rock conditions such as ultra-deep subsea tunnels and hard rock formations, it must withstand the combined effects of high impact loads, severe shear wear, and high-pressure water erosion for extended periods. The wear resistance, impact resistance, and corrosion resistance of the cutterhead surface directly determine tunneling efficiency and engineering costs. To extend the service life of the cutterhead, the industry commonly uses surface strengthening technology to improve its surface properties. Among these, laser cladding technology has become one of the mainstream processes for surface strengthening of cutterheads due to its high coating bonding strength and good forming quality. Currently, laser cladding commonly uses... Ni Basic alloys, Co While base alloy or single ceramic particle reinforced coatings can improve the wear resistance of the cutter ring to a certain extent, they are difficult to adapt to the complex requirements of multi-stress coupling under extremely hard rock conditions.

[0003] One of the core problems with existing laser cladding coatings is the insufficient performance matching between the coating and the cutterhead substrate. Traditional cladding coatings are mostly single-layer or simple composite structures, with significant differences in composition and hardness between the coating and the substrate. Stress concentration zones easily form at the interface, making the coating prone to cracking and peeling under repeated impact loads. For example, although simple ceramic particle reinforced coatings have high hardness and excellent wear resistance, they are brittle and have poor impact resistance. The interface between the coating and the metal substrate is prone to residual tensile stress due to the difference in thermal expansion coefficients. During tunneling in extremely hard rock, the coating often cracks within a short time, leading to cutterhead failure. On the other hand, although single metal alloy coatings have good toughness, their hardness is low, and their wear resistance cannot meet the long-term wear requirements of extremely hard rock, requiring frequent cutterhead replacements and significantly increasing downtime and maintenance costs.

[0004] Meanwhile, existing laser cladding processes suffer from insufficient coating density and resistance to extreme environments. In traditional laser cladding, the rapid cooling of the molten pool easily generates internal defects such as pores and inclusions. These defects become channels for corrosive media penetration under high-pressure water conditions, leading to localized corrosion of the coating and further weakening the bond strength between the coating and the substrate. Furthermore, existing processes have limited control over the coating's microstructure, resulting in coarse grains and poor impact fatigue resistance. Under cyclic impact loads in extremely hard rock conditions, the coating is prone to failure due to accumulated fatigue damage. Although some studies have optimized coating quality by adjusting process parameters such as laser power and scanning speed, these methods only partially improve coating performance and cannot achieve a synergistic improvement in hardness, toughness, and corrosion resistance. This makes it difficult to meet the comprehensive performance requirements of surface-strengthening coatings for laser cutter rings in extreme conditions such as ultra-deep seabed tunnels and hard rock formations. Summary of the Invention

[0005] The technical solution of this invention addresses the technical problems existing in the prior art and provides a solution that is significantly different from the prior art. Specifically, the purpose of this invention is to solve the above-mentioned shortcomings of the prior art and propose a gradient composite cladding coating and forming process for blade rings suitable for extremely hard rock conditions. Through the synergistic effect of three-layer gradient structure design, ultrasonic-laser coupled forming and post-processing stress release, it aims to overcome three major technical barriers: gradient performance adaptation, process synergistic control, and residual stress and compactness optimization.

[0006] This invention employs the following technical solution: a gradient composite cladding coating for cutter rings suitable for extremely hard rock conditions, wherein the gradient composite cladding coating for cutter rings, from the surface of the cutter ring substrate outwards, consists of the following layers: Ni Base interface adaptation layer Fe CoCrNi -nanometer WC tough and rigid synergy layer NiCoCrMo Multiphase ceramic wear-resistant and impact-resistant gradient layer; The Ni Base interface adaptation layer Fe CoCrNi -nanometer WC tough and rigid synergy layer NiCoCrMo The multiphase ceramic wear-resistant and impact-resistant gradient layers work together to form a continuous and smooth performance gradient, achieving a gradual improvement in hardness, toughness and wear resistance layer by layer.

[0007] In a further embodiment, the Ni The base interface adaptation layer is NiCrBSi Alloy powder or NiCoCrFe It is a high-entropy alloy powder; The Fe CoCrNi -nanometer WC tough and rigid synergistic layer Fe CoCrNi The matrix material is a high-entropy alloy, in which plasma-treated elements are uniformly dispersed. Ni -P Coating-modified nanoscale WC Particles, coating thickness 5-10 nm .

[0008] In a further embodiment, the NiCoCrMo Multiphase ceramic wear-resistant and impact-resistant gradient layer with Ni The base alloy is the matrix, and ceramic particles of nanoscale or microscale are uniformly dispersed inside it. The ceramic particles are selected from WC , TiC , NbC One or more of them, in NiCoCrMo The volume fraction of the multiphase ceramic wear-resistant and impact-resistant gradient layer is 15%-30%.

[0009] In a further embodiment, the performance gradient is specifically manifested as follows: The coating hardness exhibits a smooth gradient transition characteristic, from Ni Base interface adaptation layer to Fe CoCrNi -nanometer WC The toughness-hardness synergy layer is gradually being improved; NiCoCrMo The microhardness of the surface layer of the multiphase ceramic wear-resistant and impact-resistant gradient layer is ≥1000. HV Furthermore, the hardness difference between any regions within the coating does not exceed 150. HV; The bonding strength between the coating and the blade ring substrate is ≥ 200 MPa, Overall porosity ≤1%.

[0010] A method for forming a gradient composite cladding coating for cutter rings suitable for extremely hard rock conditions, used to prepare the gradient composite cladding coating for cutter rings as described above, includes the following steps: The surface of the blade ring substrate is subjected to a cladding surface pretreatment, which includes cladding organic solvent wiping and preheating treatment to remove surface impurities and regulate the initial temperature of the blade ring substrate; On the surface of the pretreated self-cutter ring substrate, a gradient composite cladding coating for the cutter ring is constructed by laser cladding layer-by-layer deposition. The laser cladding process is simultaneously coupled with an ultrasonic rolling-assisted process, and according to... Ni Base interface adaptation layer Fe CoCrNi -nanometer WC tough and rigid synergy layer NiCoCrMo The corresponding material composition and performance requirements of the multiphase ceramic wear-resistant and impact-resistant gradient layer, and the energy gradient adaptation mechanism formed by regulating laser energy parameters; After the coating is clad, the blade ring substrate is subjected to tempering heat treatment to release the residual stress at the interface between the coating and the blade ring substrate, and finally obtains a gradient composite cladding coating with high hardness, high bonding strength and low porosity.

[0011] In a further embodiment, the gradient control of the laser energy parameter is as follows: cladding Ni When using a base interface adapter layer, the laser power is 800-1400. W ; cladding Fe CoCrNi -nanometer WC When using a tough-hard synergistic layer, the laser power is 1400-1500. W ; cladding NiCoCrMo When creating a wear-resistant and impact-resistant gradient layer of multiphase ceramics, the laser power is 2000-2500. W ; The laser scanning speed for all three coating layers is 2-10. mm / s The overlap rate between adjacent cladding passes is 10-50%.

[0012] In a further embodiment, the process parameters of the ultrasonic rolling assisted process are: The ultrasonic rolling frequency is 20–50. kHz The ultrasonic rolling amplitude is 2–12. μm ; The ultrasonic rolling process is carried out simultaneously with the laser cladding process. While the laser heat source acts on the cladding area, high-frequency ultrasonic vibration is applied to the cladding layer.

[0013] In a further embodiment, during the pretreatment of the cladding surface, the initial temperature of the blade ring substrate is controlled to be 80–120°C.

[0014] In a further embodiment, the construction process of the laser cladding layered stepwise deposition is as follows: Complete first Ni The entire surface of the substrate interface adapter layer is clad, and after it cools to 150–200°C, it is clad again. Fe CoCrNi -nanometer WC The tough and rigid synergistic layer is then clad in final layers. NiCoCrMo Multiphase ceramic wear-resistant and impact-resistant gradient layer.

[0015] In a further embodiment, the parameters of the tempering heat treatment are: Temperature: 200–300℃, holding time: 2–3 h After the heat preservation is completed, the furnace is cooled to room temperature.

[0016] The beneficial effects of this invention: This invention, through " Ni Base Interface Adaptation Layer - Fe CoCrNi -nanometer WC tough and rigid synergistic layer - NiCoCrMoThe three-layer gradient structure design of the "multiphase ceramic wear-resistant and impact-resistant gradient layer" achieves a smooth transition in hardness and toughness between the coating and the substrate, fundamentally avoiding the risk of cracking and peeling caused by sudden changes in performance in traditional single-layer coatings.

[0017] Simultaneous coupling of ultrasonic rolling and laser cladding processes utilizes high-frequency vibration to refine coating grains and reduce porosity to ≤1%, significantly improving coating density and impact fatigue resistance. Combined with substrate temperature-controlled pretreatment and post-heat treatment, a residual stress release mechanism is constructed to further enhance the bonding stability between the coating and the substrate, achieving a bonding strength ≥200. MPa Surface microhardness ≥1000 HV .

[0018] It provides technical support for the long service life of TBM cutterheads in extreme environments such as ultra-deep seabed tunnels and hard rock formations, significantly reducing the frequency of machine downtime for cutter replacement and maintenance costs, and supporting the digital and efficient construction of tunnel boring equipment. Attached Figure Description

[0019] Picture 1 This is a schematic diagram of the gradient composite cladding coating structure of the blade ring provided in Example 1.

[0020] Picture 2 Microstructure of the gradient composite cladding coating provided in Example 1.

[0021] Picture 3 The hardness curve of the gradient composite cladding coating provided in Example 1.

[0022] Picture 4 The overall flow chart of the ultrasonic rolling assisted laser cladding process provided in Example 2 is shown. Detailed Implementation

[0023] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0024] Example 1 like Picture 1 As shown, this embodiment discloses a gradient composite cladding coating for cutter rings suitable for extremely hard rock conditions. The gradient composite cladding coating for cutter rings consists of the following layers from the surface of the cutter ring substrate outwards: Ni Base interface adaptation layer Fe CoCrNi -nanometer WC tough and rigid synergy layer NiCoCrMo Multiphase ceramic wear-resistant and impact-resistant gradient layer; The Ni Base interface adaptation layer Fe CoCrNi -nanometer WC tough and rigid synergy layer NiCoCrMo The multiphase ceramic wear-resistant and impact-resistant gradient layers work together to form a continuous and smooth performance gradient, achieving a gradual improvement in hardness, toughness and wear resistance layer by layer.

[0025] The Ni The base interface adaptation layer is NiCrBSi Alloy powder or NiCoCrFe It is a high-entropy alloy powder. NiCrBSi Taking alloy powder as an example, its elemental mass fraction is: Cr 15-18% B 2.5-3.0% Si 4.0-4.5%, C 0.8-1.2%, with the balance being Ni Powder particle size is controlled between 50-100. μm Purity ≥99.5%, must be dried in a vacuum drying oven at 80-100℃ for 1-2 days before use. h This removes the moisture adsorbed by the powder, preventing porosity defects during the cladding process.

[0026] The Fe CoCrNi -nanometer WC tough and rigid synergistic layer Fe CoCrNi The matrix material is a high-entropy alloy, in which plasma-treated elements are uniformly dispersed. Ni - P Coating-modified nanoscale WC Particles, coating thickness 5-10 nm .

[0027] Furthermore, Fe CoCrNi The molar ratio of elements in high-entropy alloys is Fe : Co : Cr : Ni =1:1:1:1, powder particle size 50-100 μm Purity ≥99.5%. Also includes nano-sized... WC Particles as reinforcing phase, WC Particle size is 50-100 nm The purity is ≥99.8%. The nanoscale [material] described in this embodiment... WC The particles were modified by plasma coating (the coating layer was...) Ni - P Alloy, thickness 5-10 nmTo enhance the interfacial bonding force between the particles and the high-entropy alloy matrix, the two are mixed at a volume ratio of 90:10-85:15 and uniformly mixed using a planetary ball mill at a milling speed of 200-300 rpm. r / min Ball-to-material ratio 5:1, mixing time 2-3 minutes h Ensure nano WC The particles are uniformly dispersed in the high-entropy alloy powder.

[0028] For ease of understanding, the specific parameters of the plasma coating modification treatment described in this embodiment are: plasma power 300-350. W Argon flow rate 15-20 L / min As an enhancing phase dispersed in Fe CoCrNi In a high-entropy alloy matrix, to improve Fe CoCrNi -nanometer WC The hardness and wear resistance of the tough-hard synergistic layer.

[0029] In a further embodiment, the present embodiment described NiCoCrMo Multiphase ceramic wear-resistant and impact-resistant gradient layer with Ni The matrix is ​​composed of a base alloy, within which nano- or micron-sized ceramic particles are uniformly dispersed; the ceramic particles are selected from... WC , TiC , NbC One or more of them, in NiCoCrMo The volume fraction of the multiphase ceramic wear-resistant and impact-resistant gradient layer is 15%-30% to synergistically improve... NiCoCrMo Impact resistance and wear resistance of multiphase ceramic wear-resistant and impact-resistant gradient layers.

[0030] To illustrate further, Ni Basic alloys, according to element mass fraction, include: Co 20-22% Cr 18-20% Mo 8-10%, with the remainder being Ni Powder particle size 50-100 μm Purity ≥ 99.5%; Reinforcing phase selected WC and TiC Composite ceramic particles, in which WC Particle size 1-5 μm , TiC Particle size 1-3 μm Both have a purity of ≥99.8%. After mixing at a volume ratio of 7:3, add 15-30% by volume. NiCoCrMo In alloy powder, the mixing method and Fe CoCrNi -nanometer WCThe tough and hard synergistic layer is consistent. The uniform dispersion of ceramic particles and matrix powder is achieved by planetary ball milling, which avoids particle agglomeration and affects the performance of the cladding coating.

[0031] The performance gradient described in this embodiment is specifically manifested as follows: The coating hardness exhibits a smooth gradient transition characteristic, from Ni Base interface adaptation layer to Fe CoCrNi -nanometer WC The toughness-hardness synergy layer is gradually being improved; NiCoCrMo The microhardness of the surface layer of the multiphase ceramic wear-resistant and impact-resistant gradient layer is ≥1000. HV Furthermore, the hardness difference between any regions within the coating does not exceed 150. HV This avoids stress concentration in the coating under impact loads caused by sudden changes in hardness. Impact wear tests have verified that the coating's impact fatigue resistance is superior to traditional coatings. Ni The base cladding layer is improved by ≥50%, and the cyclic tolerance under simulated extremely hard rock impact load is increased by more than 2 times; verified by high-pressure water corrosion tests, at 1.5 MPa Continuous immersion under hydrostatic pressure for 72 days h The coating exhibits no penetration and has no obvious corrosion spots or peeling on its surface, meeting the corrosion resistance requirements of ultra-deep subsea tunnels under high water pressure conditions.

[0032] The bonding strength between the coating and the blade ring substrate is ≥ 200 MPa, Overall porosity ≤1%. Interfacial fractures measured by tensile shear tests all occurred within the substrate or coating rather than at the interface; overall coating porosity ≤1%, and the average pore area ratio under any 5 fields of view observed by a metallographic microscope does not exceed 1%.

[0033] The testing process is as follows: The test sample was taken from a typical location in the cladding area of ​​the die ring (size 10). mm ×10 mm ×5 mm Each test group was repeated 3 times and the average value was taken to ensure data reliability.

[0034] Hardness gradient test uses HVS -1000 type microhardness tester, test load 1000 g Pressure holding time 15 s Every 50 mm from the blade ring substrate to the coating surface μm A single point was measured. The results show that the matrix hardness is approximately 280. HV , Ni Base interface adapter layer hardness 450-550 HV , Fe CoCrNi -nanometer WC The hardness of the tough-hard synergistic layer is 750-850. HV , NiCoCrMoThe surface hardness of the multiphase ceramic wear-resistant and impact-resistant gradient layer reaches 1120. HV The hardness difference between each layer is ≤130. HV This achieves a smooth gradient transition without obvious abrupt changes.

[0035] Combined with strength test GB / T The 13916-2009 standard adopts the tensile shear method, using... WDW -300 electronic universal testing machine, loading rate 0.5 mm / min Test results show that the average bond strength between the coating and the substrate is 235. MPa The fracture locations were all within the cutter ring matrix (approximately 1.2 meters from the interface). mm (place) or Fe CoCrNi -nanometer WC No interface peeling was observed within the tough-hard co-working layer, verifying the reliability of the interface bonding.

[0036] Porosity testing uses AxioObserverZ 1 m Metallurgical microscope, at 500x magnification, randomly selected 5 fields of view (each field of view area 0.5). mm ²), through Image - ProPlus The software analyzed the pore area ratio. The results showed that the average porosity of the coating was 0.6%, and most of the pores had a diameter ≤5 mm. μm It is a closed pore with no through-hole defects.

[0037] Impact fatigue testing is adopted MLD -10 type impact wear testing machine, simulating extremely hard rock conditions (impact load 50). N Impact frequency 10 Hz (The abrasive is 80-mesh quartz sand), compared to traditional Ni Base cladding layer (thickness 1.0) mm The results showed that the coating of the present invention performed well under cyclic impact. There was still no significant peeling after this, while traditional coatings showed no peeling at 1. Large-scale cracking occurred immediately, and the impact fatigue resistance was improved by 150%.

[0038] The high-pressure water corrosion resistance test was conducted in a custom-made autoclave at a set pressure of 1.5. MPa Temperature 25℃, using 3.5% NaCl The solution simulates a seawater environment, and the solution is continuously soaked for 72 hours. h The surface condition of the coating was then observed. The results of the high-pressure water corrosion resistance test showed that the coating surface had no corrosion spots, bulges, or peeling, and the corrosion rate was ≤0.005%. mm / a far below GB / T In standard 10125-2021, the corrosion rate of corrosion-resistant coatings is ≤0.01. mm / a According to the standard, no penetration was found through ultrasonic flaw detection.

[0039] In summary, the gradient composite cladding coating of this embodiment meets the design specifications in terms of hardness gradient, bonding strength, density, impact fatigue resistance and corrosion resistance, and can be stably adapted to extremely hard rock tunneling conditions.

[0040] Example 2 This embodiment discloses a method for forming a blade ring gradient composite cladding coating suitable for extremely hard rock conditions. The method is used to prepare the blade ring gradient composite cladding coating as described in Example 1, following the process of "substrate pretreatment, layered ultrasonic rolling assisted laser cladding, and post-treatment," with precise control of parameters at each stage to ensure coating quality. Picture 4 The steps shown are as follows: The surface of the blade ring substrate is subjected to a cladding surface pretreatment, which includes cladding organic solvent wiping and preheating treatment to remove surface impurities and regulate the initial temperature of the blade ring substrate; On the surface of the pretreated self-cutter ring substrate, a gradient composite cladding coating is constructed by laser cladding layer-by-layer deposition to avoid initial thermal stress caused by excessive temperature difference between the substrate and the coating during subsequent cladding. The laser cladding process is simultaneously coupled with an ultrasonic rolling-assisted process, and according to... Ni Base interface adaptation layer Fe CoCrNi -nanometer WC tough and rigid synergy layer NiCoCrMo The material composition and performance requirements of the multiphase ceramic wear-resistant and impact-resistant gradient layer are determined, and the laser energy parameters are adjusted to form an energy gradient adaptation mechanism. Through the performance gradient design of the three-layer structure, the cracking and peeling problems caused by the abrupt performance change between the traditional single-layer cladding coating and the substrate are solved.

[0041] After the coating is clad, the blade ring substrate is subjected to tempering heat treatment to release the residual stress at the interface between the coating and the blade ring substrate, and finally obtains a gradient composite cladding coating with high hardness, high bonding strength and low porosity.

[0042] Furthermore, during the pretreatment of the cladding surface, the initial temperature of the blade ring substrate is controlled at 80–120℃. For example, the blade ring substrate is placed in a medium-frequency induction heating furnace for overall preheating at a heating rate of 5℃ / ... min Heat to 100℃ and then keep warm for 30 minutes. min This ensures uniform substrate temperature and avoids thermal stress caused by excessive temperature differences during cladding.

[0043] In this embodiment, the layered cladding stage employs a synchronous coupling of ultrasonic rolling and laser cladding, with the laser energy parameter gradient controlled as follows: cladding Ni When using a base interface adapter layer, the laser power is 800-1400. W ; cladding Fe CoCrNi -nanometer WC When using a tough-hard synergistic layer, the laser power is 1400-1500. W ; cladding NiCoCrMo When creating a wear-resistant and impact-resistant gradient layer of multiphase ceramics, the laser power is 2000-2500. W ; The laser scanning speed for all three coating layers is 2-10. mm / s The overlap rate between adjacent cladding passes is 10-50%.

[0044] In a further embodiment, the process parameters of the ultrasonic rolling assisted process are: The ultrasonic rolling frequency is 20–50. kHz The ultrasonic rolling amplitude is 2–12. μm The ultrasonic rolling process is carried out simultaneously with the laser cladding process. While the laser heat source acts on the cladding area, high-frequency ultrasonic vibration is applied to the cladding layer to simultaneously achieve grain refinement and porosity reduction of the cladding layer.

[0045] In a further embodiment, the construction process of the laser cladding layered stepwise deposition is as follows: Complete first Ni The entire surface of the substrate interface adapter layer is clad, and after it cools to 150–200°C, it is clad again. Fe CoCrNi -nanometer WC The tough and rigid synergistic layer is then clad in final layers. NiCoCrMo Multiphase ceramic wear-resistant and impact-resistant gradient layer.

[0046] In a further embodiment, the parameters of the tempering heat treatment are: Temperature: 200–300℃, holding time: 2–3 h After the heat preservation is completed, the coating is cooled to room temperature in the furnace to further release the residual stress at the interface between the coating and the substrate.

[0047] To illustrate the parameters of each step above, consider the following example: cladding Ni When using the base interface adapter layer, the laser power is set to 1300. W Scanning speed 8 mm / s Powder delivery rate 20 g / min The coating thickness is controlled at 0.3 mm. mmSimultaneously activate the ultrasonic rolling device and set the frequency to 25. kHz Amplitude 10 μm The distance between the rolling head and the laser spot is maintained at 5. mm This ensures that the cladding layer is densified by high-frequency vibration immediately after solidification.

[0048] cladding Fe CoCrNi -nanometer WC Before the tough and rigid synergistic layer, first test Ni The surface temperature of the base interface adaptation layer is lowered to 180°C before cladding begins, at which point the laser power is increased to 1450 rpm. W Scanning speed 7 mm / s Powder delivery rate 22 g / min Coating thickness 0.4 mm The ultrasound parameters remained unchanged.

[0049] cladding NiCoCrMo When creating a wear-resistant and impact-resistant gradient layer of multiphase ceramics, the laser power is further increased to 2200. W To accommodate the high melting point of ceramic particles, the scanning speed was reduced to 6. mm / s Powder delivery rate 25 g / min The coating thickness is 0.3 mm. mm At the same time, the ultrasonic amplitude was finely adjusted to 11. μm This enhances the grain refinement effect on high-hardness coatings. The overlap rate of each of the three coating layers is uniformly 35%, and each layer must be cooled to below 150°C with compressed air before proceeding to the next layer.

[0050] The post-treatment stage focuses on residual stress release. After all three coating layers have been melted and the blade ring has naturally cooled to room temperature, it is placed in a box-type resistance furnace for tempering heat treatment at 3℃ / min The temperature is increased to 250℃ at a rate of [temperature value missing], and held for 2.5 [units of time missing]. h During the period every 30 min Record the furnace temperature once to ensure temperature control accuracy of ±5℃; after the holding period, turn off the heating device and allow the blade ring to cool with the furnace to below 80℃ before removing it to avoid secondary stress caused by rapid cooling. Simultaneously, lightly polish the coating surface to remove minor protrusions between cladding passes, ensuring the final overall coating thickness is controlled at 1.0±0.1 mm. mm .

[0051] The device mentioned in this embodiment includes a laser cladding module, an ultrasonic rolling auxiliary module, and a zoned temperature control pre-treatment / post-treatment unit. It adopts a wear-resistant heat dissipation structure and a high-pressure water penetration prevention sealing design adapted to extremely hard rock conditions.

Claims

1. A gradient composite cladding coating for cutter rings suitable for extremely hard rock conditions, characterized in that, The gradient composite cladding coating of the cutter ring, from the surface of the cutter ring substrate outwards, consists of the following... Ni Base interface adaptation layer FeCoCrNi -nanometer WC tough and rigid synergy layer NiCoCrMo Multiphase ceramic wear-resistant and impact-resistant gradient layer; The Ni Base interface adaptation layer FeCoCrNi -nanometer WC tough and rigid synergy layer NiCoCrMo The multiphase ceramic wear-resistant and impact-resistant gradient layers work together to form a continuous and smooth performance gradient, achieving a gradual improvement in hardness, toughness and wear resistance layer by layer.

2. The gradient composite cladding coating for cutter rings suitable for extremely hard rock conditions according to claim 1, characterized in that, The Ni The base interface adaptation layer is NiCrBSi Alloy powder or NiCoCrFe It is a high-entropy alloy powder; The FeCoCrNi -nanometer WC tough and rigid synergistic layer FeCoCrNi The matrix material is a high-entropy alloy, in which plasma-treated elements are uniformly dispersed. Ni - P Coating-modified nanoscale WC Particles, coating thickness 5-10 nm .

3. The gradient composite cladding coating for cutter rings suitable for extremely hard rock conditions according to claim 1, characterized in that, The NiCoCrMo Multiphase ceramic wear-resistant and impact-resistant gradient layer with Ni The base alloy is the matrix, and ceramic particles of nanoscale or microscale are uniformly dispersed inside it. The ceramic particles are selected from WC , TiC , NbC One or more of them, in NiCoCrMo The volume fraction of the multiphase ceramic wear-resistant and impact-resistant gradient layer is 15%-30%.

4. The gradient composite cladding coating for cutter rings suitable for extremely hard rock conditions according to claim 1, characterized in that, The performance gradient is specifically manifested as follows: The coating hardness exhibits a smooth gradient transition characteristic, from Ni Base interface adaptation layer to FeCoCrNi -nanometer WC The toughness-hardness synergy layer is gradually being improved; NiCoCrMo The microhardness of the surface layer of the multiphase ceramic wear-resistant and impact-resistant gradient layer is ≥1000. HV Furthermore, the hardness difference between any regions within the coating does not exceed 150. HV; The bonding strength between the coating and the blade ring substrate is ≥ 200MPa Overall porosity ≤1%.

5. A method for forming a blade ring gradient composite cladding coating suitable for extremely hard rock conditions, used to prepare the blade ring gradient composite cladding coating as described in any one of claims 1 to 4, characterized in that, Includes the following steps: The surface of the blade ring substrate is subjected to a cladding surface pretreatment, which includes cladding organic solvent wiping and preheating treatment to remove surface impurities and regulate the initial temperature of the blade ring substrate; On the surface of the pretreated self-cutter ring substrate, a gradient composite cladding coating for the cutter ring is constructed by laser cladding layer-by-layer deposition. The laser cladding process is simultaneously coupled with an ultrasonic rolling-assisted process, and according to... Ni Base interface adaptation layer FeCoCrNi -nanometer WC tough and rigid synergy layer NiCoCrMo The corresponding material composition and performance requirements of the multiphase ceramic wear-resistant and impact-resistant gradient layer, and the energy gradient adaptation mechanism formed by regulating laser energy parameters; After the coating is clad, the blade ring substrate is subjected to tempering heat treatment to release the residual stress at the interface between the coating and the blade ring substrate, and finally obtains a gradient composite cladding coating with high hardness, high bonding strength and low porosity.

6. The method for forming a gradient composite cladding coating for cutter rings suitable for extremely hard rock conditions according to claim 5, characterized in that, The gradient control of the laser energy parameters is as follows: cladding Ni When using a base interface adapter layer, the laser power is 800-1400. W ; cladding FeCoCrNi -nanometer WC When using a tough-hard synergistic layer, the laser power is 1400-1500. W ; cladding NiCoCrMo When creating a wear-resistant and impact-resistant gradient layer of multiphase ceramics, the laser power is 2000-2500. W ; The laser scanning speed for all three coating layers is 2-10. mm / s The overlap rate between adjacent cladding passes is 10-50%.

7. The method for forming a gradient composite cladding coating for cutter rings suitable for extremely hard rock conditions according to claim 5, characterized in that, The process parameters for the ultrasonic rolling assisted process are as follows: The ultrasonic rolling frequency is 20–50. kHz The ultrasonic rolling amplitude is 2–12. μm ; The ultrasonic rolling process is carried out simultaneously with the laser cladding process. While the laser heat source acts on the cladding area, high-frequency ultrasonic vibration is applied to the cladding layer.

8. The method for forming a gradient composite cladding coating for cutter rings suitable for extremely hard rock conditions according to claim 5, characterized in that, During the pretreatment of the cladding surface, the initial temperature of the blade ring substrate is controlled at 80–120℃.

9. The method for forming a gradient composite cladding coating for cutter rings suitable for extremely hard rock conditions according to claim 6, characterized in that, The construction process of the laser cladding layered stepwise deposition is as follows: Complete first Ni The entire surface of the substrate interface adapter layer is clad, and after it cools to 150–200°C, it is clad again. FeCoCrNi -nanometer WC The tough and rigid synergistic layer is then clad in final layers. NiCoCrMo Multiphase ceramic wear-resistant and impact-resistant gradient layer.

10. The method for forming a gradient composite cladding coating for cutter rings suitable for extremely hard rock conditions according to claim 5, characterized in that, The parameters for the tempering heat treatment are: Temperature: 200–300℃, holding time: 2–3 h After the heat preservation is completed, the furnace is cooled to room temperature.

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