A titanium nitride-silver composite thin film material and its preparation method
The titanium nitride-silver composite thin film prepared by magnetron sputtering solves the problem of balancing low infrared emissivity and durability in lightweight unmanned aerial vehicles (UAVs), achieving an integration of low infrared emissivity with excellent resistance to damp heat and salt spray, making it suitable for infrared stealth and protection of lightweight UAVs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- JILIN UNIVERSITY
- Filing Date
- 2026-05-11
- Publication Date
- 2026-06-26
AI Technical Summary
Existing technologies struggle to balance low infrared emissivity and excellent durability in lightweight unmanned aerial vehicles (LS-UAVs). Traditional coatings increase weight, damage the casing, and have poor durability. Research on titanium nitride-silver composite thin films has yet to solve problems such as uneven component dispersion and weak interfacial bonding.
Titanium nitride-silver composite thin films were prepared by magnetron sputtering. TiN was a rhombohedral phase with a (015) preferred orientation, and Ag was a cubic phase with a (002) preferred orientation. The grain sizes were 2.4 nm and 2.0 nm, and the Ag content was 4.4 at.%. The infrared emissivity of the film in the 8-14 μm band was 0.10, and it still met the requirement of less than 0.20 after damp heat and salt spray tests.
It achieves the integration of low infrared emissivity with excellent resistance to damp heat and salt spray, adapting to the lightweight and heat-sensitive requirements of light drones. The film emissivity increases only slightly in extreme environments, and the durability is significantly improved.
Smart Images
Figure CN122279481A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of functional thin film materials technology, specifically relating to a titanium nitride-silver composite thin film material with low infrared emissivity, resistance to damp heat and salt spray, and its preparation method. Background Technology
[0002] Low infrared emissivity thin film materials are core functional materials in the fields of infrared stealth and thermal management, possessing irreplaceable application value in key areas such as high-end unmanned equipment and aerospace. Especially in lightweight unmanned aerial vehicles (LS-UAVs), their performance directly determines the infrared stealth effect and battlefield survivability of the equipment. Currently, durable low infrared emissivity thin film technology faces severe challenges. Existing technologies struggle to balance low infrared emissivity with excellent durability and cannot adapt to the specific usage requirements of lightweight equipment, becoming a "bottleneck" problem restricting my country's ability to seize strategic high ground in high-end unmanned equipment.
[0003] Traditional low infrared emissivity coating technologies are mainly divided into two categories. One is thermal spraying of metal-based composite coatings used in large aerospace equipment. These coatings are prepared through thermal spraying processes, achieving thicknesses ranging from micrometers to millimeters, and the preparation process requires exposure to high-temperature environments. Although they can achieve a certain degree of low infrared emissivity, the extremely high requirements for lightweight airframes in LS-UAVs, coupled with the fact that the airframes are mostly made of heat-sensitive materials such as aluminum alloys, mean that thick coatings would significantly increase the equipment's weight and affect flight endurance. Furthermore, the high-temperature process could damage the airframe and lead to performance degradation. Therefore, this type of coating cannot be applied to LS-UAVs.
[0004] To meet the lightweight and heat-sensitive requirements of light equipment, existing technologies reduce film thickness to the nanometer / micrometer level, mainly including conductive metal oxide films (such as ATO, ITO, AZO, etc.) and metal / dielectric multilayer films (such as Al / SiO2, etc.). Conductive metal oxide films have good light transmittance and conductivity, but when considering durability requirements such as wear resistance and corrosion resistance, the infrared emissivity still remains above 0.30, which is far from the ideal index (≤0.20) required by high-end equipment. Moreover, long-term service is prone to oxidation, cracking, and peeling. Metal / dielectric multilayer films achieve low emissivity by utilizing the high reflectivity of the metal layer. Some silver-based films can achieve emissivity as low as about 0.13. However, silver is chemically reactive and easily oxidized and sulfided, resulting in poor mechanical properties and wear resistance. In addition, the film has weak adhesion to the substrate and the preparation process is complex, making it difficult to meet the requirements of long-term service.
[0005] Titanium nitride (TiN) possesses excellent mechanical properties, wear resistance, corrosion resistance, and high-temperature stability, and also exhibits a certain degree of electrical conductivity. When combined with silver, TiN is expected to compensate for the durability shortcomings of silver films, while silver's high reflectivity can achieve low infrared emissivity, thus resolving the inherent contradiction of achieving both. However, current research on titanium nitride-silver composite thin films, both domestically and internationally, is still in the exploratory stage. Existing composite thin films suffer from problems such as uneven component dispersion, weak interfacial bonding, and complex preparation processes, making it impossible to simultaneously achieve a synergistic effect of low infrared emissivity and excellent durability. Furthermore, they are difficult to adapt to the processing requirements of heat-sensitive substrates such as LS-UAV housings, and thus cannot meet the practical application needs of high-end unmanned equipment. Summary of the Invention
[0006] The purpose of this invention is to overcome the aforementioned problems in conventional technologies and provide a titanium nitride-silver composite thin film material with low infrared emissivity, resistance to damp heat and salt spray, and its preparation method.
[0007] To achieve the above-mentioned technical objectives and effects, the present invention is implemented through the following technical solution:
[0008] This invention provides a titanium nitride-silver composite thin film material, which is a nanocomposite thin film of titanium nitride and silver, wherein TiN is a rhombohedral phase TiN with a preferred (015) orientation. 0.58 The grain size is 2.4 nm, and Ag is a cubic phase element with a preferred (002) orientation and a grain size of 2.0 nm; the atomic compositions of Ti, N, and Ag are 59.0%, 36.6%, and 4.4%, respectively, denoted as TiN. 0.62 -Ag 0.08 .
[0009] Furthermore, in the above-mentioned titanium nitride-silver composite thin film material, the infrared emissivity of the thin film in the 8-14 μm band is 0.10.
[0010] Furthermore, in the aforementioned titanium nitride-silver composite thin film material, the infrared emissivity of the film increases from 0.10 to 0.12 after one cycle of damp heat testing; the cycle of damp heat testing is divided into three stages:
[0011] a) Heating phase: from 30℃ to 65℃, humidity 95%, duration 2 hours;
[0012] b) High temperature and high humidity stage: 65℃, 95% humidity, duration 6h;
[0013] c) Cooling phase: 65℃ to 30℃, humidity 95%, duration 16h.
[0014] Furthermore, in the above-mentioned titanium nitride-silver composite thin film material, after a cumulative 16 hours of salt spray testing, the infrared emissivity of the film increased from 0.10 to 0.14; the conditions for the salt spray test were: sodium chloride solution concentration 5%±1wt.%, pH value 6.5~7.2, with 4 hours of spraying followed by 4 hours of drying as one cycle, and the tests were carried out alternately.
[0015] This invention also provides a method for preparing a titanium nitride-silver composite thin film material, which employs magnetron sputtering and includes the following steps:
[0016] 1) Substrate cleaning: Select silicon wafers or carbon fiber sheets as substrates and clean them sequentially with acetone, ethanol, and deionized water using ultrasonic cleaning.
[0017] 2) Vacuum preparation: Place the pure Ti target and the pure Ag target into the magnetron sputtering chamber and evacuate to 4 × 10⁻⁶. -4 Pa;
[0018] 3) Sputtering deposition: N2 and Ar are introduced, and the sputtering power of Ti target and Ag target is adjusted to deposit TiN-Ag thin film on the substrate.
[0019] Furthermore, in step 3), the pure Ti target uses an RF power supply with a sputtering power of 150W; the pure Ag target uses an RF power supply with a sputtering power of 30-50W.
[0020] Further, the sputtering conditions in step 3) are as follows: target-substrate distance 21.5 cm, substrate temperature 200 °C, working pressure 1.0 Pa, bias voltage -80 V; N2 flow rate 10 sccm, Ar flow rate 200 sccm; sample rotation 5 r / min, sputtering time 5 min.
[0021] This invention also provides the application of titanium nitride-silver composite thin film material in the preparation of infrared stealth, moisture-resistant, and salt-spray-resistant surface protection materials for lightweight unmanned aerial vehicles.
[0022] The beneficial effects of this invention are:
[0023] 1. The introduction of Ag increases the electron concentration of the film. When the Ag content is 4.4 at.%, the infrared emissivity of the film in the 8-14 μm band is as low as 0.10, which is close to the infrared emissivity of the Al film (0.05). Compared with the pure TiN film (0.39), the emissivity is reduced by 74%. The emissivity of this film meets the practical application requirements of less than 0.20 and can achieve excellent infrared stealth effect.
[0024] 2. After one cycle of damp heat test, the emissivity of the film increased from 0.10 to 0.12, an increase of only 20%, still meeting the practical application requirement of less than 0.20. In contrast, after the same damp heat test, the emissivity of the aluminum film (Al film) increased from 0.05 to 0.80, an increase of 15 times. The damp heat resistance of the film is 75 times that of the aluminum film, and it can adapt to extreme environments with high temperature and high humidity.
[0025] 3. After a cumulative 16 hours of salt spray testing, the emissivity increased from 0.10 to 0.14, an increase of 40%, while still meeting the practical application requirement of less than 0.20. In contrast, after the same salt spray test, the emissivity of the aluminum film (Al film) increased from 0.05 to 0.60, an increase of 11 times. The salt spray resistance of this film is 27.5 times that of the aluminum film, which can effectively resist salt spray corrosion and is suitable for the protection of UAVs in salt spray environments such as shipborne applications.
[0026] 4. Through the design of metal-ceramic nanocomposite structure, the integration of low infrared emissivity and high resistance to damp heat and salt spray is achieved, which solves the technical problem that is difficult to achieve in the existing technology. No additional protective layer is required, simplifying the preparation process and reducing costs. At the same time, it is suitable for the lightweight and heat-sensitive requirements of small and light drones.
[0027] 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
[0028] 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.
[0029] Figure 1 XPS atomic composition diagrams of pure TiN film and TiN-Ag composite film containing 4.4 at.% silver;
[0030] Figure 2 X-ray diffraction patterns of pure TiN film and TiN-Ag composite film containing 4.4 at.% silver;
[0031] Figure 3 The XPS narrow scan spectrum of the TiN-Ag composite film containing 4.4 at.% silver includes the core energy level spectra of Ti, N, and Ag.
[0032] Figure 4 Infrared emission spectra of pure Al film, pure TiN film, and TiN-Ag composite film containing 4.4 at.% silver are shown.
[0033] Figure 5 Infrared emission spectra of TiN-Ag composite film containing 4.4 at.% silver and pure Al film before and after one cycle of damp heat test;
[0034] Figure 6 The infrared emission spectra of the TiN-Ag composite film containing 4.4 at.% silver and the pure Al film before and after a cumulative 16 hours of salt spray testing are shown. Detailed Implementation
[0035] 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.
[0036] Example 1
[0037] This embodiment provides a titanium nitride-silver composite thin film material, which is composed of rhombohedral TiN with a preferred (015) orientation. 0.58 A TiN-Ag film composed of cubic Ag with a preferred (002) orientation, wherein the atomic compositions of Ti, N, and Ag are 59.0%, 36.6%, and 4.4%, respectively, denoted as TiN. 0.62 -Ag 0.08 (like Figure 1 ).
[0038] The preparation method of the above-mentioned titanium nitride-silver composite thin film material includes the following steps:
[0039] 1) Select a silicon wafer or carbon fiber sheet as the substrate and ultrasonically clean it in acetone, ethanol and deionized water for 20 minutes each.
[0040] 2) Place the pure Ti target and Ag target into the magnetron sputtering chamber, adjust the target-to-substrate distance to 21.5 cm, and evacuate to 4 × 10⁻⁶. -4 Pa, the substrate is heated to 200℃, the pure Ti target uses an RF power supply with a sputtering power of 150W, and the pure Ag target uses an RF power supply with a sputtering power of 30-50W.
[0041] 3) Introduce N2 gas and Ar gas. The flow rate of N2 gas is 10 sccm and the flow rate of Ar gas is 200 sccm. The working pressure and bias voltage are 1.0 Pa and -80 V, respectively. The sample rotation is 5 r / min. Deposit a TiN-Ag film on the substrate and the sputtering time is 5 min.
[0042] In this embodiment, Ag was successfully introduced into a TiN film to prepare a TiN-Ag composite film. XRD results show that the titanium nitride is a rhombohedral phase TiN with a (015) preferred orientation. 0.58 The grain size is 2.4 nm, while it exists as a cubic elemental form of Ag with a (002) preferred orientation, with a grain size of 2.0 nm. Figure 2 ).
[0043] XPS test results further confirmed that Ag remained elemental in the composite film and did not form chemical bonds with Ti or N, while Ti-N covalent bonds were stably formed between Ti atoms and N atoms. Figure 3 ).
[0044] When the Ag content is 4.4 at.%, TiN-Ag x The composite structure film achieves optimal overall performance. Within this range, the infrared emissivity in the 8-14 μm band is only 0.10, close to that of the Al film (0.05), and is 74% lower than that of the pure TiN film (0.39). Figure 4 This meets the practical application requirements of less than 0.20.
[0045] When the Ag content was 4.4 at.%, after one cycle of damp heat test, including a heating phase (30℃ to 65℃, 95% humidity, 2h), a high temperature and high humidity phase (65℃, 95% humidity, 6h), and a cooling phase (65℃ to 30℃, 95% humidity, 16h), the emissivity of the film increased from 0.10 to 0.12, an increase of only 20%, still meeting the practical application requirement of less than 0.20. In contrast, after the same damp heat test, the emissivity of the aluminum film (Al film) increased from 0.05 to 0.80, an increase of 15 times. The damp heat resistance of the film is 75 times that of the aluminum film. Figure 5 ).
[0046] When the Ag content was 4.4 at.%, in a sodium chloride solution with a concentration of 5% ± 1 wt.% and a pH of 6.5–7.2, after 16 hours of salt spray testing with alternating cycles of 4 hours of spraying followed by 4 hours of drying, the emissivity increased from 0.10 to 0.14, an increase of 40%, still meeting the practical application requirement of less than 0.20. In contrast, after the same salt spray test, the emissivity of the aluminum film (Al film) increased from 0.05 to 0.60, an increase of 11 times. The salt spray resistance of this film is 27.5 times that of the aluminum film. Figure 6 ).
[0047] Example 2
[0048] This embodiment provides a durable thin film material with low infrared emissivity. It uses a Group 4 transition metal nitride (TiN, ZrN, or HfN) as the matrix and forms a metal-ceramic nanocomposite structure with silver. The metal remains elemental, and the ceramic retains its original phase structure, exhibiting both low infrared emissivity and resistance to damp heat and salt spray. The preparation method is similar to that of Example 1, except that the pure Ti target is replaced with a target material corresponding to the Group 4 transition metal nitride, and the target thin film can be obtained by adjusting the sputtering parameters.
[0049] 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 titanium nitride-silver composite thin film material, characterized in that, The thin film material is a nanocomposite structure film of titanium nitride and silver, wherein TiN is a rhombohedral phase TiN with a preferred (015) orientation. 0.58 The grain size is 2.4 nm, and Ag is a cubic phase element with a preferred (002) orientation and a grain size of 2.0 nm; the atomic compositions of Ti, N, and Ag are 59.0%, 36.6%, and 4.4%, respectively, denoted as TiN. 0.62 -Ag 0.08 .
2. The titanium nitride-silver composite thin film material according to claim 1, characterized in that, The thin film has an infrared emissivity of 0.10 in the 8–14 μm band.
3. The titanium nitride-silver composite thin film material according to claim 1, characterized in that, After one cycle of damp heat test, the infrared emissivity of the film increased from 0.10 to 0.12; the cycle of damp heat test consisted of three stages: a) Heating phase: from 30℃ to 65℃, humidity 95%, duration 2 hours; b) High temperature and high humidity stage: 65℃, 95% humidity, duration 6h; c) Cooling phase: 65℃ to 30℃, humidity 95%, duration 16h.
4. The titanium nitride-silver composite thin film material according to claim 1, characterized in that, After a cumulative 16 hours of salt spray testing, the infrared emissivity of the film increased from 0.10 to 0.
14. The conditions for the salt spray test were: sodium chloride solution concentration of 5% ± 1 wt.%, pH value of 6.5 to 7.2, with 4 hours of spraying followed by 4 hours of drying as one cycle, and the tests were carried out alternately.
5. The method for preparing the titanium nitride-silver composite thin film material as described in claim 1, wherein magnetron sputtering is employed, characterized in that... Includes the following steps: 1) Substrate cleaning: Select silicon wafers or carbon fiber sheets as substrates and clean them sequentially with acetone, ethanol, and deionized water using ultrasonic cleaning. 2) Vacuum preparation: Place the pure Ti 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 Ti target and Ag target is adjusted to deposit TiN-Ag thin film on the substrate.
6. The preparation method according to claim 5, characterized in that, In step 3), the pure Ti target uses an RF power supply with a sputtering power of 150W; the pure Ag target uses an RF power supply with a sputtering power of 30-50W.
7. The preparation method according to claim 6, characterized in that, The sputtering conditions for step 3) are as follows: target-substrate distance 21.5 cm, substrate temperature 200 °C, working pressure 1.0 Pa, bias voltage -80 V; N2 flow rate 10 sccm, Ar flow rate 200 sccm; sample rotation 5 r / min, sputtering time 5 min.
8. The application of the titanium nitride-silver composite thin film material as described in any one of claims 1-4 in the preparation of infrared stealth, moisture-resistant, and salt-spray-resistant surface protection materials for lightweight unmanned aerial vehicles.