A high-silver introduced hafnium nitride low-infrared emissivity durable thin film material and a preparation method thereof

Abstract

This invention belongs to the field of functional thin film materials technology, and discloses a high-silver-doped hafnium nitride (HfN-Agx) low-infrared-emissivity durable thin film material and its preparation method. It aims to solve the problem of existing technologies failing to simultaneously achieve low infrared emissivity and environmental durability, meeting the extreme operating conditions requirements of lightweight unmanned aerial vehicles (UAVs). The thin film is a silver-doped hafnium nitride solid solution (HfN-Agx), with an Ag atom percentage of 2.9–3.3 at.% (preferably 3.1 at.%), and an infrared emissivity ≤0.05 in the 3–12 μm band, exhibiting excellent wear resistance and corrosion resistance. Preparation is achieved using magnetron sputtering, involving three steps: substrate cleaning, vacuum preparation, and sputtering deposition. The target thin film can be obtained by adjusting the sputtering parameters of the Hf and Ag targets. This invention achieves performance integration through solid solution structure design, and its wear resistance, acid and salt resistance are far superior to Al films. It can be widely used in infrared stealth and surface protection for lightweight UAVs, possessing significant scientific research and application value.

Description

Technical Field

[0001] This invention belongs to the field of functional thin film materials technology, specifically relating to a low infrared emissivity durable thin film material with high silver content and hafnium nitride and its preparation method. Background Technology

[0002] Lightweight and compact unmanned aerial vehicles (LS-UAVs) with dimensions ≤100 cm, as strategic equipment reshaping the future form of warfare, are driving equipment iteration and upgrading in the field of military-civilian integration due to their advantages of lightweight architecture, low-cost manufacturing, low observability, high mobility, and multi-mission integration. They are deeply penetrating military fields such as reconnaissance and guidance, and tactical strikes, and comprehensively empowering civilian scenarios such as resource exploration, disaster relief, geographic mapping, security inspection, and logistics transportation, demonstrating significant consumer market potential, commercial application prospects, and strategic scientific research value. With the leapfrog development of my country's independent innovation system for UAVs, various military / civilian LS-UAVs have completed technical verification at domestic air shows such as Zhuhai and Beijing, as well as international air shows such as Paris, Farnborough, Dubai, and Singapore. With the deepening of the integrated air, space, and sea strategy, LS-UAVs are accelerating their paradigm shift from auxiliary equipment to a core equipment system: deep space exploration UAVs need to maintain the thermal stability of precision instruments under high-energy particle irradiation; stratospheric solar-powered UAVs must ensure photoelectric conversion efficiency while withstanding impacts and scratches from hard objects; and shipborne cruise UAVs urgently need to overcome the challenge of infrared stealth in salt spray-humid heat coupled corrosion environments. These extreme conditions pose disruptive technological requirements for surface functional materials—the development of advanced thin-film systems that combine environmental durability (wear resistance, corrosion resistance, etc.) with low infrared emissivity (emissivity less than 0.20 in the 8-14μm band).

[0003] Current technologies for durable, low-infrared-emissivity thin-film systems are facing severe challenges. The inherent conflict between micrometer / millimeter-level thickness and high-temperature processing and the lightweight and heat-sensitive housing materials required for LS-UAVs means that thermally sprayed metal-based composite coatings used in large aircraft cannot be applied to LS-UAVs. Although existing technologies have reduced film thickness to the nanometer / micrometer level, such as conductive metal oxide films (e.g., ATO, ITO, AZO) and metal / dielectric multilayer films (e.g., Al / SiO2), the infrared emissivity remains above 0.30 when considering durability requirements, still falling short of the ideal. This exposes a fundamental contradiction between durability and low infrared emissivity that traditional technological approaches cannot resolve, becoming a major obstacle to my country's dominance in the high-end unmanned equipment market. Summary of the Invention

[0004] The purpose of this invention is to overcome the aforementioned problems in conventional technologies and provide a durable thin film material with low infrared emissivity and high silver-introduced hafnium nitride, and its preparation method. This material has both low infrared emissivity and good wear resistance and corrosion resistance.

[0005] To achieve the above-mentioned technical objectives and effects, the present invention is implemented through the following technical solution: This invention provides a durable thin film material with low infrared emissivity, characterized in that the thin film material is a silver-doped hafnium nitride solid solution thin film, which is formed by HfN and Ag to form a solid solution structure, denoted as HfN-Ag. x The atomic percentage of Ag is 2.9–3.3 at.%.

[0006] Furthermore, the atomic percentage of Ag is 3.1 at.%.

[0007] Furthermore, the thin film has an infrared emissivity of ≤0.05 in the 3–12 μm band.

[0008] Furthermore, the wear rate of the film under Al2O3 ball abrasion conditions is 1.03 × 10⁻⁶. -5 mm 3 / N -1 m -1 .

[0009] Furthermore, the corrosion current density of the film in a 0.5 mol / L H₂SO₄ solution is 1.14 × 10⁻⁶. -5 A / cm 2 The corrosion current density in a 3.5 wt.% NaCl solution is 1.90 × 10⁻⁶. -6 A / cm 2 .

[0010] This invention also provides a method for preparing a thin film material using magnetron sputtering, comprising the following steps: 1) Substrate cleaning: Select silicon wafers or glass as substrates and clean them sequentially with acetone, ethanol, and deionized water using ultrasonic cleaning. 2) Vacuum preparation: Load the pure Hf target and the pure Ag target into the magnetron sputtering chamber, and evacuate to 4×10⁻⁶. -4 Pa; 3) Sputtering deposition: N2 and Ar are introduced, and the sputtering power of Hf and Ag targets is adjusted to deposit HfN-Ag on the substrate. x film.

[0011] Furthermore, in step 3), the pure Hf target uses a DC power supply with a sputtering power of 150W; the pure Ag target uses an RF power supply with a sputtering power of 40-60W.

[0012] Further, the sputtering conditions in step 3) are as follows: target-substrate distance 70 mm, substrate temperature 200 °C, working pressure 1.0 Pa, bias voltage -160 V; N2 flow rate 2.8 sccm, Ar flow rate 80 sccm; sample rotation 5 r / min, sputtering time 60 min.

[0013] This invention also provides a low infrared emissivity durable thin film material, which uses group IV transition metal nitrides (TiN, ZrN, HfN) as the matrix, incorporates silver to form a solid solution, and constructs an electron-rich strong covalent bond network, which has the properties of low infrared emissivity, wear resistance and corrosion resistance.

[0014] This invention also provides an application of thin film material in infrared stealth and wear-resistant and corrosion-resistant surface protection for lightweight unmanned aerial vehicles.

[0015] The beneficial effects of this invention are: 1. Low infrared emissivity: The introduction of Ag increases the electron concentration of the film, resulting in an infrared emissivity of 0.05 in the 3-12μm band, which is close to the infrared emissivity of Al film (0.03).

[0016] 2. High wear resistance: When the Ag content is 3.1%, the wear rate of the coating against Al2O3 spheres is 1.03×10⁻⁶. -5 mm 3 / N·m, which is 11 times that of Al film.

[0017] 3. High corrosion resistance: In 0.5 mol / L H2SO4 solution and 3.5 wt.% NaCl solution, the corrosion current density of this film is as low as 1.14 × 10⁻⁶. -5 A / cm 2 and 1.90×10 -6 A / cm 2 Its acid resistance and salt resistance are 25 times and 53 times that of Al film, respectively.

[0018] 4. High degree of technology integration: Through solid solution structure design, it achieves the integration of low infrared emissivity and high wear resistance and corrosion resistance, solving the technical problem that is difficult to achieve in existing technologies.

[0019] Of course, any product implementing this invention does not necessarily need to achieve all of the above advantages at the same time. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 X-ray diffraction patterns of pure hafnium nitride film and hafnium nitride film containing 3.1% silver; Figure 2 Infrared emission spectra of hafnium nitride film containing 3.1% silver and pure Al film; Figure 3 Wear diagrams of hafnium nitride film containing 3.1% silver and pure Al film; Figure 4 For 0.5 mol l -1 Potentiodynamic polarization curves of a 3.1% silver hafnium nitride film and a pure Al film in H2SO4 solution; Figure 5 The potentiodynamic polarization curves are shown for a hafnium nitride film containing 3.1% silver and a pure Al film in a 3.5 wt.% NaCl solution. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1 A solid solution structure thin film material with silver-introduced hafnium nitride film, the material being HfN-Ag composed of HfN and Ag. x The membrane contains 3.1 at.% Ag.

[0024] The preparation method of the material in this embodiment is as follows: 1) Select a glass substrate as the substrate and ultrasonically clean it in acetone, ethanol and deionized water for 20 min each in sequence; 2) Place the pure Hf target and Ag target into the magnetron sputtering chamber, adjust the target-to-substrate distance to 70 mm, and evacuate to 4 × 10⁻⁶ mm. -4 Pa, the substrate is heated to 200℃, the pure Hf target uses a DC power supply and the sputtering power is set to 150W, the pure Ag target uses an RF power supply and the sputtering power is set to 50W. 3) Introduce N2 and Ar gases at a flow rate of 2.8 sccm and 80 sccm respectively. Set the working pressure and bias voltage to 1.0 Pa and -160 V, respectively. Allow the sample to rotate at 5 r / min. Deposit HfN-Ag on the substrate. x Film sputtering time 60 min.

[0025] In this embodiment, Ag is introduced into the HfN membrane to prepare HfN-Ag. xThe introduction of Ag increases the electron concentration of the film, resulting in a low emissivity due to the abundance of electrons; simultaneously, Ag and HfN exist in the form of a solid solution. Figure 1 This generates strong covalent bonds, giving the material both good wear resistance and corrosion resistance. When the Ag content is 3.1%, the overall performance of the film reaches its optimal level; within this range, the infrared emissivity in the 3-12 μm band is only 0.05 (…). Figure 2 The infrared emissivity is close to that of the Al film (0.03).

[0026] When the Ag content is 3.1%, the wear rate of this coating against Al2O3 spheres is 1.03 × 10⁻⁶. -5 mm 3 / N -1 m -1 ( Figure 3 The wear resistance is Al (11.76 × 10⁻⁶). -5 mm 3 / N -1 m -1 11 times that of ).

[0027] When the Ag content is 3.1%, the film is in 0.5 mol / L -1 The corrosion current densities in H2SO4 and 3.5 wt.% NaCl solutions are 1.14 × 10⁻⁶. -5 Acm -2 ( Figure 4 ) and 1.90×10 -6 Acm -2 ( Figure 5 The acid resistance and salt resistance of the aluminum film (2.90×10) are respectively -4 Acm -2 1.02×10 -4 Acm -2 25 times and 53 times that of ).

[0028] Example 2 This embodiment provides a low infrared emissivity durable thin film material, which uses a group 4 transition metal nitride (TiN, ZrN or HfN) as the matrix, incorporates silver to form a solid solution, and constructs an electron-rich strong covalent bond network, which has the properties of low infrared emissivity, wear resistance and corrosion resistance.

[0029] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A durable thin film material with low infrared emissivity, characterized in that, The thin film material is a silver-doped hafnium nitride solid solution film, which is a solid solution structure formed by HfN and Ag, denoted as HfN-Ag. x The atomic percentage of Ag is 2.9–3.3 at.%.

2. The thin film material according to claim 1, characterized in that, The atomic percentage of Ag is 3.1 at.%.

3. The thin film material according to claim 1, characterized in that, The thin film has an infrared emissivity of ≤0.05 in the 3–12 μm band.

4. The thin film material according to claim 1, characterized in that, The wear rate of the film under Al2O3 ball abrasion conditions was 1.03 × 10⁻⁶. -5 mm 3 / N -1 m -1 .

5. The thin film material according to claim 1, characterized in that, The corrosion current density of the film in 0.5 mol / L H2SO4 solution is 1.14 × 10⁻⁶. -5 A / cm 2 The corrosion current density in a 3.5 wt.% NaCl solution is 1.90 × 10⁻⁶. -6 A / cm 2 .

6. The method for preparing the thin film material according to any one of claims 1 to 5, characterized in that, The magnetron sputtering method includes the following steps: 1) Substrate cleaning: Select silicon wafers or glass as substrates and clean them sequentially with acetone, ethanol, and deionized water using ultrasonic cleaning. 2) Vacuum preparation: Load the pure Hf target and the pure Ag target into the magnetron sputtering chamber, and evacuate to 4×10⁻⁶. -4 Pa; 3) Sputtering deposition: N2 and Ar are introduced, and the sputtering power of Hf and Ag targets is adjusted to deposit HfN-Ag on the substrate. x film.

7. The preparation method according to claim 6, characterized in that, In step 3), the pure Hf target uses a DC power supply with a sputtering power of 150W; the pure Ag target uses an RF power supply with a sputtering power of 40-60W.

8. The preparation method according to claim 6, characterized in that, Step 3) Sputtering conditions: target-substrate distance 70 mm, substrate temperature 200 °C, working pressure 1.0 Pa, bias voltage -160 V; N2 flow rate 2.8 sccm, Ar flow rate 80 sccm; sample rotation 5 r / min, sputtering time 60 min.

9. A durable thin film material with low infrared emissivity, characterized in that, Using group 4 transition metal nitrides as the parent material, silver is incorporated to form a solid solution, thereby constructing an electron-rich, strongly covalent network.

10. The application of the thin film material according to any one of claims 1 to 5 and 9 in infrared stealth and wear-resistant and corrosion-resistant surface protection for lightweight unmanned aerial vehicles.

Images