Ice skate blade TiN composite coating and preparation method thereof

Abstract

The invention belongs to the field of hard coatings, and particularly relates to an ice skate blade TiN composite coating and a preparation method thereof.The ice skate blade TiN composite coating comprises a titanium bottoming layer, a heat conduction regulation and control layer and an ice scrap repelling layer which are sequentially arranged from inside to outside; the heat conduction regulation and control layer is of a columnar crystal TiN structure doped with rare earth elements and has the following characteristics that when the interface temperature is larger than or equal to-25 DEG C and smaller than 0 DEG C, the heat conductivity ranges from 3 W / mK to 8 W / mK; when the interface temperature is greater than or equal to 0 DEG C and the shear stress is less than 1.0 GPa, the columnar crystal maintains the initial orientation, and the thermal conductivity is 8-12W / mK; when the interface temperature is greater than or equal to 0 DEG C and the shear stress is 1.0-2.0 GPa, the columnar crystal is subjected to orientation rearrangement under the action of shear force, and the thermal conductivity is 22-30W / mK. The heat conduction regulation and control layer can rapidly generate a water film at low temperature and rapidly dissipate heat at high temperature and high shear force, so that the water film is prevented from being too thick. The ice scrap repelling layer can actively promote the ice scraps to be quickly separated from the ice skate blade, and the abrasive paper effect generated by ice scrap accumulation is avoided.

Description

Technical Field

[0001] This invention belongs to the field of hard coatings, and in particular to a TiN composite coating for ice skates and its preparation method. Background Technology

[0002] To improve the wear resistance of ice skate blades and reduce gliding resistance, a wear-resistant coating is typically applied to the blade. Traditional wear-resistant coatings can be found in existing technologies such as the drag-reducing composite coating process for ice skate surfaces disclosed in invention patent application CN202310248190.8, the ice skate and its manufacturing method disclosed in invention application CN202110504404.4, and ice skates. The traditional approach involves increasing the hardness of the wear-resistant material and reducing the coefficient of friction to improve the blade's hardness and reduce gliding resistance. However, due to limitations in the material's inherent properties, the effectiveness is limited.

[0003] Chinese invention application CN201910280681.4 discloses a novel ice skate drag reduction technology and its implementation method. By modifying the surface of the ice skate substrate, the thermal conductivity of the ice skate is significantly reduced, as is the heat loss caused by frictional heat conduction to the substrate. This increases the heat flow distribution coefficient from frictional heat to the ice surface, allowing more frictional heat to be used to melt the ice surface and increase the thickness of the water-lubricating film, thus achieving water-based lubrication drag reduction, significantly reducing the ice surface friction coefficient, and improving the tribological properties of the ice skate. However, this technology has the following problems: when skating continuously at high speeds, the frictional heat generation is large, and the ice melting rate is too fast, resulting in an excessively thick water film between the ice skate and the ice surface. This leads to a suction effect and a sharp increase in water film viscous resistance, which in turn significantly increases skating resistance.

[0004] In addition, when ice skate blades cut the ice surface, they also produce a large number of fine ice chips. If the ice chips cannot be removed from the blade in time, they will accumulate on both sides of the blade, forming a sandpaper effect and scraping the ice surface, causing additional resistance. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a TiN composite coating for ice skates and its preparation method, which can prevent the water film from being too thick, and at the same time promote the rapid removal of ice chips and reduce gliding resistance.

[0006] To solve the above problems, the technical solution adopted by the present invention is: a TiN composite coating for ice skates, comprising a titanium underlayer, a thermal conductivity control layer and an ice chip repellency layer arranged sequentially from the inside to the outside; The thermal conductivity control layer is a columnar TiN structure doped with rare earth elements, and the thermal conductivity control layer has the following characteristics: When -25℃≤interface temperature<0℃, the thermal conductivity is 3-8W / mK; When the interface temperature is ≥0℃ and the shear stress is <1.0GPa, the columnar crystals maintain their initial orientation and the thermal conductivity is 8-12W / mK. When the interface temperature is ≥0℃ and the shear stress is 1.0-2.0GPa, the columnar crystals undergo orientation rearrangement under the action of shear force, and the thermal conductivity is 22-30W / mK.

[0007] Furthermore, the rare earth element is lanthanum or cerium, and the rare earth content is 1 at%-3 at%.

[0008] Furthermore, the ice chip repellent layer comprises, from the inside out, an amorphous carbon-based thin film, a ferroelectric material layer doped with HfO2 or AlScN, and a polytetrafluoroethylene nanofiber array layer.

[0009] Furthermore, the polytetrafluoroethylene nanofiber array layer has fibers that are vertically or obliquely oriented, an array porosity of 60%-85%, and a nanoscale wrinkled structure formed on the fiber surface by plasma etching.

[0010] Furthermore, the thickness of the amorphous carbon-based thin film is 1.5-3.0 μm, the thickness of the ferroelectric material layer is 50-200 nm, the diameter of a single fiber in the polytetrafluoroethylene nanofiber array layer is 100-500 nm, the fiber length is 1-5 μm, and the overall thickness of the array layer is 2-10 μm.

[0011] Furthermore, the thickness of the titanium underlayer is 0.1-0.3 μm, and the thickness of the thermally conductive control layer is 2-5 μm.

[0012] The above-mentioned method for preparing the TiN composite coating for ice skates includes the following steps: S1. Pre-treat the ice skate substrate; S2. A titanium underlayer is deposited on the ice blade substrate using magnetron sputtering. S3. A thermally conductive control layer is deposited using a multi-arc ion plating process: the target material is a Ti-La alloy target, nitrogen gas is introduced, the deposition temperature is 450℃-550℃, the bias voltage is -150V to -200V, and a columnar TiN structure doped with rare earth elements is deposited. S4, Deposited ice debris repulsion layer.

[0013] Further, step S4 includes: S41. High-power pulsed magnetron sputtering is used to deposit amorphous carbon-based thin films on the thermally conductive control layer; S42. A ferroelectric material layer doped with HfO2 or AlScN is deposited on an amorphous carbon-based thin film by atomic layer deposition or radio frequency magnetron sputtering. S43. Using electrospinning combined with electric field orientation technology, a polytetrafluoroethylene nanofiber array layer is constructed on the surface of the ferroelectric material layer, and a nanoscale wrinkled structure is formed by plasma etching.

[0014] Further, in step S3, the La content in the Ti-La alloy target is 1-3 at%, the nitrogen partial pressure during deposition is 1.0-2.0 Pa, and the deposition time is 50-90 minutes.

[0015] Further, step S1 includes: mirror polishing the ice blade substrate, followed by ion etching cleaning in a vacuum furnace to remove the surface oxide layer and activate the surface.

[0016] The beneficial effects of this invention are as follows: The titanium base layer is made of pure titanium material, which has good toughness and lattice compatibility. It can effectively alleviate the lattice mismatch and internal stress caused by the difference in crystal structure and thermal expansion coefficient between the ice skate substrate and the outer thermal control layer. It significantly improves the overall film-substrate adhesion of the coating and avoids the failure of the coating such as cracking and peeling under high-speed gliding, impact and alternating stress. It provides a stable and reliable support foundation for the outer functional layer.

[0017] By utilizing the intrinsic thermal conductivity anisotropy of TiN material and combining it with the grain boundary pinning effect of rare earth doping, a thermal conductivity modulation layer with stress-thermal synergistic response was constructed: When the sliding speed is low, there is less frictional heat generation and the temperature is low. Regardless of the shear stress, the pinning effect of rare earth elements on the TiN grain boundaries is dominant, and the grains maintain their original random orientation. At this time, the thermal conductivity is low (3-8 W / mK). A large number of grain boundaries and rare earth doped atoms form strong phonon scattering centers, which inhibit the rapid conduction of heat along the inside of the coating, making the coating exhibit low thermal conductivity characteristics. The heat generated by friction is concentrated in the near-surface area of ​​the coating, which can quickly melt the surface ice layer and form a stable, continuous thin water lubricating film, reducing sliding resistance.

[0018] When the interface temperature reaches the freezing point or above, it indicates that a melting water film has been formed at the interface. However, when the sliding shear stress is small (<1.0 GPa), the shear stress is insufficient to overcome the grain boundary pinning effect of rare earth elements. The TiN columnar crystals still maintain their initial orientation structure. Compared with the low temperature range, the interface temperature rise slightly weakens the grain boundary scattering and slightly increases the thermal conductivity (8–12 W / mK). This ensures a certain water film thickness to maintain lubrication while avoiding rapid heat loss that could cause the water film to freeze prematurely, thus achieving a mild and stable lubrication state.

[0019] When the ice skate is gliding at high speed, interfacial friction intensifies, and the temperature remains above freezing. Simultaneously, the contact shear stress reaches the level of 1.0–2.0 GPa. Under this shear stress, the TiN columnar crystals overcome grain boundary pinning forces and rearrange their orientation along the gliding direction, forming highly oriented phonon transport channels. These channels laterally conduct excess frictional heat along the coating plane to the non-contact area of ​​the ice skate blade, and further transfer it to the ice skate substrate and the surrounding low-temperature environment for dissipation. This prevents heat from continuously accumulating at the friction interface, which could lead to excessive melting, and also prevents an excessively thick water film from creating a suction effect, thus ensuring the water film effectively reduces drag.

[0020] The ice chip repellent layer can actively promote the rapid removal of ice chips from the ice skates, solving the sandpaper effect caused by ice chip accumulation and further reducing gliding resistance. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the TiN composite coating on the ice skates of the present invention; Figure reference numerals: 1—Titanium base layer; 2—Thermal conductivity control layer; 3—Ice chip repellency layer; 31—Amorphous carbon-based thin film; 32—Ferroelectric material layer; 33—Polytetrafluoroethylene nanofiber array layer; 10—Ice blade substrate. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] The TiN composite coating for ice skates of the present invention, such as Figure 1 As shown, it includes a titanium base layer 1, a thermal conductivity control layer 2, and an ice chip repellency layer 3 arranged sequentially from the inside to the outside; The thermal conductivity control layer 2 is a columnar TiN structure doped with rare earth elements, with a thickness of 2-5 μm. The rare earth element is lanthanum or cerium, and the rare earth content is 1 at%-3 at%. The thermal conductivity control layer 2 of this invention has the following characteristics: When -25℃ ≤ interface temperature < 0℃, the thermal conductivity is 3-8 W / mK. Since the temperature of an ice rink is unlikely to drop below -25℃, we will only consider the case where the temperature is above -25℃.

[0024] When the interface temperature is ≥0℃ and the shear stress is <1.0GPa, the columnar crystals maintain their initial orientation and the thermal conductivity is 8-12W / mK. When the interface temperature is ≥0℃ and the shear stress is 1.0-2.0 GPa, the columnar crystals undergo orientation rearrangement under shear force, and the thermal conductivity is 22-30 W / mK. When ice skates glide, shear stress is generated between the coating and the ice layer due to friction. Generally, this shear stress can hardly exceed 2.0 GPa. Therefore, we only consider the case where the shear stress is less than or equal to 2.0 GPa.

[0025] The titanium underlayer 1, with a thickness of 0.1-0.3 μm, is deposited on the blade surface of the ice skate substrate 10. Titanium possesses excellent toughness and lattice compatibility, effectively mitigating lattice mismatch and internal stress caused by differences in crystal structure and thermal expansion coefficients between the ice skate substrate 10 and the outer TiN layer. This significantly enhances the overall film-substrate adhesion of the coating, preventing coating cracking and peeling under high-speed gliding, impact, and alternating stress, thus providing a stable and reliable support foundation for the outer functional layer.

[0026] The thermal conductivity of this invention refers to the thermal conductivity in the direction perpendicular to the coating thickness (i.e., parallel to the side of the ice skate blade).

[0027] The thermal conductivity regulation layer 2 is mainly composed of columnar TiN. TiN single crystals exhibit significant anisotropy in thermal conductivity across different crystal orientations, meaning that the ease with which phonons propagate along different crystal orientations varies; phonon propagation rates are high in some orientations and slow in others. This anisotropy is an intrinsic property of TiN, originating from differences in atomic density and bonding strength across different crystal orientations.

[0028] In this invention, by doping with rare earth elements (La or Ce) and controlling the multi-arc ion plating process, TiN columnar crystals grow perpendicular to the substrate (width 50-300 nm, aspect ratio ≥ 5:1), meaning the length direction of the TiN columnar crystals is consistent with the entire coating thickness direction, and the rare earth elements are concentrated at the grain boundaries of the columnar crystals. Rare earth atoms have a large atomic radius (more than 30% larger than Ti atoms), and their solid solubility in the TiN lattice is limited. During deposition, rare earth atoms are "pushed away" by the growing grain boundaries, eventually concentrating in the grain boundary region, forming a grain boundary pinning effect (see existing literature: Zhang J, Wang L, et al. Microstructure and mechanical properties of La-doped TiN coatings deposited by cathodic arcevaporation [J]. Surface and Coatings Technology, 2020, 395: 125923. DOI:10.1016 / j.surfcoat.2020.125923). This pinning effect anchors the grain boundaries, inhibits grain boundary slip, and has low thermal conductivity in the direction perpendicular to the length of the columnar crystals (i.e., perpendicular to the coating thickness), giving the coating thermal barrier properties and transferring frictional heat to the ice layer for melting ice to generate a water film.

[0029] When the ice skates glide at high speed, the shear stress between the coating interface and the ice layer increases sharply. When the shear stress reaches a threshold (1.0 GPa) and the temperature reaches above the freezing point, the following physical processes occur: The immense shear stress overcomes the pinning force of rare earth atoms, causing the columnar crystals to begin undergoing minute grain boundary slip along the shear direction. Sustained high shear stress induces plastic deformation in the columnar crystals, which initially extend along the coating thickness direction, gradually shifting towards a direction perpendicular to the coating thickness. Once a large number of grains have completed their orientation rearrangement, the phonon transport path changes from "across grain boundaries + low thermal conductivity orientation" to "along the grain interior + high thermal conductivity orientation," resulting in a jump in thermal conductivity from 8-12 W / mK to a high thermal conductivity state of 22-30 W / mK in the direction perpendicular to the coating thickness.

[0030] Before orientation rearrangement, phonon transport requires frequent crossing of rare-earth pinned grain boundaries (resulting in severe interface scattering), and the transport direction corresponds to the low thermal conductivity crystal orientation of TiN single crystals, thus resulting in low thermal conductivity. After orientation rearrangement, phonons mainly transport along the interior of columnar crystals (avoiding grain boundary scattering), and the transport direction corresponds to the high thermal conductivity crystal orientation of TiN single crystals, thus leading to a significant jump in thermal conductivity.

[0031] Temperature plays a "prerequisite" role in the above process. Generally, the thermal conductivity of columnar TiN structures increases slowly with increasing temperature. When the interface temperature is below 0℃, the thermal conductivity can be maintained at 3-8 W / mK. Even if the shear stress reaches the threshold, large-scale, ordered grain rotation and rearrangement cannot be achieved due to weak atomic vibrations and brittle grain boundaries at low temperatures. Therefore, when the interface temperature is below 0℃, the coating can maintain a low thermal conductivity (3-8 W / mK) regardless of the shear force. When the temperature is above or equal to 0℃, if the shear force does not reach the threshold, the thermal conductivity is mainly affected by temperature and remains at 8-12 W / mK; when the shear force reaches the threshold, the thermal conductivity increases rapidly.

[0032] The thermal conductivity of this invention refers to the thermal conductivity in the direction perpendicular to the coating thickness. When the thermal conductivity is low, the heat generated by friction is not easily dissipated along the coating, but mainly propagates along the coating thickness direction, with most of it being transferred to the ice layer for melting and a small portion being transferred to the ice skates. When the thermal conductivity is high, the heat is transferred along the direction parallel to the coating to the ice skates outside the ice layer and can be dissipated quickly.

[0033] The present invention can automatically adjust the thermal conductivity of the heat-conducting control layer 2 according to the temperature and gliding speed, so as to ensure that a water film is generated quickly when gliding at low speed, while avoiding the water film thickness being too large when gliding at high speed, which would increase the gliding resistance.

[0034] The ice chip repellency layer 3 is used to promote the rapid removal of ice chips from the ice skates, avoid the sandpaper effect caused by the accumulation of ice chips, and thus further reduce gliding resistance.

[0035] In this invention, the ice chip repellent layer 3 comprises, from the inside out, an amorphous carbon-based thin film 31, a ferroelectric material layer 32 doped with HfO2 or AlScN, and a polytetrafluoroethylene nanofiber array layer 33.

[0036] The amorphous carbon-based thin film 31 has a thickness of 1.5-3.0 μm, serving as a rigid support and simultaneously as a charge collection and transport layer. The resistivity of the amorphous carbon-based thin film 31 is preferably 10⁻⁶. -2 Up to 10 2 The Ω·cm ensures sufficient lateral charge transport capability while avoiding the depletion of polarization charge due to the formation of a complete ohmic contact with the ferroelectric material layer 32.

[0037] The thickness of the ferroelectric material layer 32 is 50-200 nm. Ferroelectric materials doped with HfO2 or AlScN exhibit spontaneous polarization, and their polarization direction can change with external fields (stress, temperature). During ice skating, the mechanical stress and thermal field generated by friction act on the ferroelectric material layer 32, causing polarization reversal and generating dynamically changing bound charges on the surface. This creates a strong localized electric field at the nanoscale, the intensity and direction of which dynamically change with the skating state (stress magnitude, temperature), forming a dynamic electric field. This dynamic electric field is effective against weakly polarized ice chips (ice crystals with OH groups on their surface). - and H + It generates a continuous electrostatic repulsion force to prevent ice chips from adhering.

[0038] The polytetrafluoroethylene (PTFE) nanofiber array layer 33 has a single fiber diameter of 100-500 nm, a fiber length of 1-5 μm, and an overall array layer thickness of 2-10 μm. The fibers are oriented vertically or at an angle; that is, the fiber length direction of the PTFE nanofiber array layer 33 is aligned with the coating thickness direction, or forms an acute angle with it. The array porosity is 60%-85%, and the fiber surface is etched with plasma to form a nanoscale wrinkled structure.

[0039] Polytetrafluoroethylene (PTFE) is located at the most negative end of the triboelectric series and readily generates a negative charge when rubbed against ice (positively charged). This invention utilizes electrospinning combined with electric field orientation technology to construct vertically or obliquely oriented PTFE nanofiber arrays (fiber diameter 100-500 nm, length 1-5 μm). This structure possesses the following functions: Physical ejection: When ice chips hit nanofibers, the fibers bend and deform like tiny cantilever beams, storing elastic energy, and then quickly rebound, ejecting the ice chips from the surface.

[0040] Low surface energy and anti-stick properties: PTFE has extremely low surface energy, making it difficult for ice particles to adhere to its surface. The nanoscale wrinkled structure formed by plasma etching further reduces the surface energy and enhances the anti-stick effect.

[0041] The polytetrafluoroethylene (PTFE) nanofiber array layer 33 is in direct contact with the ice layer. During gliding, frictional charging occurs between the ice chips and the PTFE nanofiber array layer 33. Electrons from the ice chips transfer to the PTFE nanofiber array layer 33, causing a continuous accumulation of negative electrostatic charge on the surface of the PTFE nanofiber array layer 33. Meanwhile, the ice chips lose electrons and become positively charged and polar (with OH groups on their surface). - and H + This provides a charge basis for subsequent electrostatic repulsion. Simultaneously, due to polarization reversal, dynamic bound charges are induced on the inner and outer surfaces of the ferroelectric material layer 32, supplementing and stabilizing the interfacial electric field and preventing static charges from being rapidly shielded by the ice film and water vapor. The negative charges generated on the surface of the polytetrafluoroethylene nanofiber array layer 33 are first conducted along the fiber body to the fiber root. These negative charges enter the ferroelectric material layer 32 and superimpose with the bound charges generated by the polarization of the ferroelectric material, forming a stable surface charge. Triboelectric charging provides a stable base charge, while the dynamic polarization of the ferroelectric layer compensates in real time for the electric field attenuation caused by water film shielding or charge neutralization. The combination of these two factors achieves a dynamic-static combination and long-term stability of the interfacial electric field. The amorphous carbon-based thin film 31 possesses high conductivity and high toughness. Serving as a charge collection layer and charge transport channel, it rapidly and laterally disperses locally concentrated charges across the entire coating interface, preventing excessive local charge from causing breakdown or dissipation. Excess charge is further conducted through the amorphous carbon-based thin film 31 to the inner thermal conductivity control layer 2 and the ice blade substrate 10, achieving dynamic charge balance and dissipation, and maintaining a stable interfacial electric field. During the aforementioned charge generation and transport process, the polytetrafluoroethylene nanofiber array layer 33 and the ferroelectric material layer 32 together form a stable and dynamically renewed negatively charged electrostatic field at the coating-ice interface. Because the ice chips generated by gliding are positively charged and polarized, they are subjected to Coulomb repulsion under the electrostatic field, making it difficult for them to adhere to and remain on the coating surface.

[0042] The dynamic electric field generated by the ferroelectric material layer 32 and the physical ejection effect of the PTFE nanofiber array create a synergistic effect: the electric field suspends ice chips on the coating surface, reducing the contact pressure between the ice chips and the fibers; the physical ejection of the fibers kicks the ice chips out of the contact area. The combination of these two factors achieves efficient active repulsion of ice chips.

[0043] When the thickness of the amorphous carbon-based thin film 31 is too thin (<1μm), it cannot isolate the interference of the electric field on the underlying TiN, and its wear resistance is insufficient; when the thickness is too thick (>3μm), the internal stress is too large and it is easy to peel off, and the thermal resistance is too large, which affects the heat dissipation of the heat-conducting layer. 1.5-3.0μm is the optimal range that balances electrical insulation and mechanical properties.

[0044] The polarization intensity of ferroelectric materials is related to their thickness. When the thickness is <50nm, the size effect causes the ferroelectricity to disappear, making it impossible to generate a sufficient electric field; when the thickness is >200nm, the grains are coarse, the surface roughness increases, and short-circuit charges are easily generated. A thickness of 50-200nm can balance strong polarization and flexibility.

[0045] The diameter of the polytetrafluoroethylene nanofiber array layer 33 needs to be smaller than the characteristic size of ice chips (micrometer level) to achieve effective ejection; the fiber length needs to ensure a sufficient aspect ratio (>10:1) to provide flexibility, but it cannot be too long to avoid collapsing and sticking together. A diameter of 100-500 nm and a length of 1-5 μm is the optimal balance range. When the porosity is too low (<60%), the fiber density is too high, and adhesion is likely to occur; when the porosity is too high (>85%), the number of effective fibers is insufficient, and the repulsive effect decreases. A porosity of 60%-85% can provide sufficient repulsive surface while ensuring fiber independence.

[0046] The method for preparing the TiN composite coating for ice skates of the present invention includes the following steps: S1. Pre-treatment of the ice skate base 10. Specifically, the ice skate base 10 is made of spring steel with a thickness of 1.5 mm. The ice skate base 10 is mirror polished to achieve a surface roughness Ra≤0.05μm. It is then placed in a vacuum furnace and evacuated to a vacuum level of 5×10⁻⁶. -3 Pa, introduce Ar gas to 0.5 Pa, apply a bias voltage of -800V, and perform ion etching cleaning for 15 minutes to remove the surface oxide layer and activate the surface.

[0047] S2. A titanium underlayer 1 is deposited on the ice blade substrate 10 using magnetron sputtering. A pure Ti target (99.9% purity) is used, with an arc current of 80A and a bias voltage of -200V. The titanium underlayer 1 has a thickness of 0.2μm. This layer is used to alleviate the lattice mismatch between the ice blade substrate 10 and the TiN coating, and to improve the adhesion.

[0048] S3. Deposit thermal conductivity control layer 2 using a multi-arc ion plating process: The target material is a Ti-La alloy target, in which the La content is 1-3 at% (atomic percentage), preferably 2 at%. First, evacuate to 5×10 -3 The deposition process involves applying pressures of Pa, followed by the introduction of nitrogen gas at a partial pressure of 1.0-2.0 Pa, preferably 1.5 Pa. The deposition temperature is 450℃-550℃, preferably 480℃. The bias voltage is -150V to -200V, preferably -180V (duty cycle 40%). The arc current is 90A, and the deposition time is 50-90 minutes, preferably 60 minutes. This results in the deposition of a columnar TiN structure doped with rare earth elements.

[0049] This process allows for the control of the thermal conductivity regulation layer 2 thickness to be maintained between 2-5 μm by controlling the deposition time and deposition rate. The deposition rate is mainly affected by the arc current and the target ionization rate, with the arc current controlling the target evaporation rate. Increasing the arc current increases the number of target metal ions ionized per unit time, resulting in more ions reaching the substrate and thus increasing the deposition rate. An arc current of 90 A is the optimal value balancing deposition efficiency and film quality—too low (<70 A) leads to a slow deposition rate, while too high (>110 A) easily generates large particle spatter. Under a stable deposition rate, the deposition thickness exhibits a linear relationship with time. Under the parameters of this process, the TiN deposition rate is approximately 40-60 nm / min, therefore, 50-90 minutes corresponds to a thickness of approximately 2-5 μm. Appropriate bias voltage enhances the ion bombardment energy, densifying the film without significantly reducing the deposition rate.

[0050] Deposition temperature is crucial for obtaining columnar crystals. At excessively low temperatures (<400℃), atomic mobility is insufficient, resulting in incomplete film growth and the formation of loose, conical crystals or amorphous structures. Excessively high temperatures (>600℃) tend to generate coarse equiaxed crystals and may deteriorate the matrix structure. At a moderate temperature of 450-550℃, deposited atoms possess sufficient surface migration ability and tend to grow along the direction of lowest energy (perpendicular to the substrate), forming a typical columnar crystal structure. An appropriate negative bias voltage attracts ions to bombard the substrate surface perpendicularly, enhancing the preferred growth perpendicular to the substrate. Within a bias voltage range of -150V to -200V, TiN films exhibit a typical columnar crystal morphology. Too low a bias voltage results in insufficient ion energy and indistinct columnar crystals; too high a bias voltage leads to excessive bombardment, potentially disrupting lattice order. An appropriate nitrogen partial pressure ensures the TiN stoichiometry while maintaining plasma density, supporting continuous columnar crystal growth.

[0051] The columnar crystal size is determined by both nucleation density and growth rate, with bias voltage directly affecting ion bombardment energy. As the pulse bias voltage increases, the columnar crystal structure becomes finer, and the film becomes denser. This is because a higher bias voltage enhances ion bombardment, inhibits excessive grain growth, and promotes secondary nucleation, keeping the columnar crystal width within the nanoscale. A bias voltage of -150 to -200V is precisely the optimal range for grain refinement without damage. At a suitable deposition temperature, the atomic mobility is appropriate, allowing grain growth without coarsening. If the temperature is too high, atomic diffusion is too rapid, resulting in coarse grains, and the columnar crystal width may exceed 300 nm. Appropriate nitrogen partial pressure ensures sufficient reaction and avoids the formation of a Ti-rich phase, which can lead to abnormal grain growth. The aspect ratio, the ratio of the length to the width of the TiN columnar crystals, ensures a columnar crystal width of 50-300 nm with a total thickness of 2-5 μm, guaranteeing an aspect ratio of at least 2 μm / 300 nm = 6.7, meeting design requirements.

[0052] Therefore, the present invention can ensure that TiN columnar crystals grow in a direction perpendicular to the substrate, with a width of 50-300 nm, an aspect ratio of ≥5:1, and La elements segregating at the grain boundaries of the columnar crystals.

[0053] S4, Deposited ice debris repulsion layer 3.

[0054] The ice chip repellent layer 3 of the present invention comprises, from the inside out, an amorphous carbon-based thin film 31, a ferroelectric material layer 32 doped with HfO2 or AlScN, and a polytetrafluoroethylene nanofiber array layer 33. Therefore, step S4 specifically includes: S41. High-power pulsed magnetron sputtering is used to deposit an amorphous carbon-based thin film 31 on the thermally conductive control layer 2. A specific and feasible high-power pulsed magnetron sputtering (HiPIMS) process is as follows: using a graphite target, a pulse power density of 1.5 kW / cm², a pulse frequency of 500 Hz, a pulse width of 100 μs, an Ar gas partial pressure of 0.8 Pa, and a deposition time of 30 minutes, an amorphous carbon thin film with a thickness of 2.0 μm can be obtained, which meets the thickness requirements.

[0055] S42. A ferroelectric material layer 32 doped with HfO2 or AlScN is deposited on an amorphous carbon-based thin film 31 using atomic layer deposition (ALD) or radio frequency magnetron sputtering. A specific feasible atomic layer deposition (ALD) process is as follows: the precursors are HfCl4 and H2O, the deposition temperature is 280℃, the number of cycles is 600, and an HfO2 thin film with a thickness of 120nm is obtained, which meets the thickness requirements.

[0056] S43. Using electrospinning combined with electric field orientation technology, a polytetrafluoroethylene nanofiber array layer 33 is constructed on the surface of the ferroelectric material layer 32, and a nanoscale wrinkled structure is formed by plasma etching. A specific feasible electrospinning combined with electric field orientation process is as follows: spinning solution: PTFE emulsion (solid content 10wt%), with polyvinyl alcohol (PEO) added as a template agent; spinning voltage: 25kV; receiving distance: 15cm; additional transverse electric field: 10kV, used to induce vertical fiber orientation; spinning time: 20 minutes.

[0057] After spinning, the fibers are sintered at 380°C for 2 hours to remove the PEO template, leaving pure PTFE fibers. Subsequently, Ar plasma etching is performed for 5 minutes to form a nanoscale wrinkled structure on the fiber surface.

[0058] The obtained PTFE fibers have a diameter of 200-400 nm, a length of 2-4 μm, are vertically oriented, and have an array porosity of about 75%.

[0059] 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 TiN composite coating for ice skates, characterized in that, It includes a titanium base layer (1), a thermally conductive control layer (2), and an ice chip repellency layer (3) arranged sequentially from the inside to the outside. The thermal conductivity control layer (2) is a columnar TiN structure doped with rare earth elements, and the thermal conductivity control layer (2) has the following characteristics: When -25℃≤interface temperature<0℃, the thermal conductivity is 3-8W / mK; When the interface temperature is ≥0℃ and the shear stress is <1.0GPa, the columnar crystals maintain their initial orientation and the thermal conductivity is 8-12W / mK. When the interface temperature is ≥0℃ and the shear stress is 1.0-2.0GPa, the columnar crystals undergo orientation rearrangement under the action of shear force, and the thermal conductivity is 22-30W / mK.

2. The TiN composite coating for ice skates as described in claim 1, characterized in that, The rare earth element is lanthanum or cerium, and the rare earth content is 1at%-3at%.

3. The TiN composite coating for ice skates as described in claim 1, characterized in that, The ice chip repellency layer (3) includes an amorphous carbon-based thin film (31), a ferroelectric material layer doped with HfO2 or AlScN (32), and a polytetrafluoroethylene nanofiber array layer (33) arranged sequentially from the inside to the outside.

4. The TiN composite coating for ice skates as described in claim 3, characterized in that, The polytetrafluoroethylene nanofiber array layer (33) has fibers that are vertically or obliquely oriented, and the array porosity is 60%-85%. The fiber surface is formed with a nanoscale wrinkled structure by plasma etching.

5. The TiN composite coating for ice skates as described in claim 3, characterized in that, The thickness of the amorphous carbon-based thin film (31) is 1.5-3.0 μm, the thickness of the ferroelectric material layer (32) is 50-200 nm, the diameter of a single fiber of the polytetrafluoroethylene nanofiber array layer (33) is 100-500 nm, the fiber length is 1-5 μm, and the overall thickness of the array layer is 2-10 μm.

6. The TiN composite coating for ice skates as described in claim 1, characterized in that, The thickness of the titanium base layer (1) is 0.1-0.3 μm, and the thickness of the thermally conductive control layer (2) is 2-5 μm.

7. The method for preparing the TiN composite coating for ice skates according to claim 1, characterized in that, Includes the following steps: S1. Pre-treat the ice skate substrate (10); S2. A titanium underlayer (1) is deposited on the ice blade substrate (10) by magnetron sputtering. S3. A thermally conductive control layer is deposited using a multi-arc ion plating process (2): The target material is a Ti-La alloy target, nitrogen gas is introduced, the deposition temperature is 450℃-550℃, the bias voltage is -150V to -200V, and a columnar TiN structure doped with rare earth elements is deposited. S4, Deposited ice debris repulsion layer (3).

8. The method for preparing the TiN composite coating for ice skates according to claim 7, characterized in that, Step S4 includes: S41. Amorphous carbon-based thin film (31) is deposited on the thermally conductive control layer (2) by high-power pulsed magnetron sputtering. S42. A ferroelectric material layer (32) doped with HfO2 or AlScN is deposited on an amorphous carbon-based thin film (31) by atomic layer deposition or radio frequency magnetron sputtering. S43. Using electrospinning combined with electric field orientation technology, a polytetrafluoroethylene nanofiber array layer (33) is constructed on the surface of the ferroelectric material layer (32), and a nanoscale wrinkled structure is formed by plasma etching.

9. The method for preparing the TiN composite coating for ice skates according to claim 7, characterized in that, In step S3, the La content in the Ti-La alloy target is 1-3 at%, the nitrogen partial pressure during deposition is 1.0-2.0 Pa, and the deposition time is 50-90 minutes.

10. The method for preparing the TiN composite coating for ice skates according to claim 7, characterized in that, Step S1 includes: mirror polishing the ice blade substrate (10), followed by ion etching cleaning in a vacuum furnace to remove the surface oxide layer and activate the surface.

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